CN103326350B - Inverter controller, energy conversion system, photovoltaic energy conversion system and method - Google Patents

Inverter controller, energy conversion system, photovoltaic energy conversion system and method Download PDF

Info

Publication number
CN103326350B
CN103326350B CN201210080623.5A CN201210080623A CN103326350B CN 103326350 B CN103326350 B CN 103326350B CN 201210080623 A CN201210080623 A CN 201210080623A CN 103326350 B CN103326350 B CN 103326350B
Authority
CN
China
Prior art keywords
isolated island
signal
protection module
energy
output
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201210080623.5A
Other languages
Chinese (zh)
Other versions
CN103326350A (en
Inventor
公茂忠
谭卓辉
刘云峰
邬雪琴
朱慧斌
大卫.史密斯
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by General Electric Co filed Critical General Electric Co
Priority to CN201210080623.5A priority Critical patent/CN103326350B/en
Priority to PCT/US2013/033062 priority patent/WO2013142553A2/en
Publication of CN103326350A publication Critical patent/CN103326350A/en
Application granted granted Critical
Publication of CN103326350B publication Critical patent/CN103326350B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/388—Islanding, i.e. disconnection of local power supply from the network
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
    • Y02E40/30—Reactive power compensation

Abstract

The present invention discloses a kind of energy conversion system, and it comprises converter device, becomes to export energy for the input power conversion provided by energy source, and inverter controller, for real component and the idle component of regulation output energy.This inverter controller comprises isolated island protection module, it is for receiving the electrical parameter values measured by this converter device output, and at least produce isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement, and this isolated island disturbing signal and disturbance compensation signal function become to regulate in this output energy in real component and idle component any one or all, the electrical parameter values of this measurement is shifted out outside normal range (NR) when there is isolated island situation.

Description

Inverter controller, energy conversion system, photovoltaic energy conversion system and method
Technical field
Execution mode disclosed by the invention relates to energy conversion system and method, particularly a kind of system and method detected the isolated island situation of this energy conversion system.
Background technology
Electricity generation system, particularly distributed generation system (such as, photovoltaic generating system and wind generator system etc.) there is so-called " isolated island " operation conditions, it refers to that distributed generation system is with after main electrical network disconnects and being electrically connected, and still continues to provide electric energy to a part for electric system.The electricity generation system run under " isolated island " situation can cause the misgivings of some secure contexts.Wherein misgivings are when electrical network is lost or depart from connection, if sent with charge free the personnel making working service do not recognize its part of carrying out keeping in repair still when receiving the electric energy that electricity generation system provides, may be subjected to security impairments.Another misgivings is when electrical network trips, this electrical network can lose the control of voltage to the electric energy that electricity generation system sends and frequency, therefore, when electrical network recovers again, larger phase difference may be there is between line voltage and current transformer output voltage, and large phase difference may cause larger impulse current to flow to electricity generation system, thus the DC-to-AC converter etc. in electricity generation system may be damaged.
Industry has developed to be made some industrial standards (such as, IEEE1547 and UL1741) and solves above-mentioned safety worries.Usually; these Industry standards call electricity generation systems need to possess anti-islet operation function; also be; islet operation situation can be detected by the protection mechanism arranged especially; and within the regular hour, (such as, in 2 seconds) connection (or stopping to local load supplying) between electricity generation system and local load can be disconnected after islet operation situation being detected.Basically, existing island detection method can be divided into two classes.The first kind is passive type detection method, and it is by detecting voltage or the frequency of electricity generation system output passively, and when the measured value of detected voltage or frequency exceedes default threshold value or default threshold range, carries out corresponding isolated island fence operation.Equations of The Second Kind island detection method is active detection method, it is by introducing a less disturbing signal (such as to system on one's own initiative, frequency disturbance signal, meritorious disturbing signal or reactive disturbance signal), then positive feedback mechanism act under, the voltage of electricity generation system output or frequency are shifted out default threshold range, thus realizes the detection of islet operation.But above-mentioned two kinds of detection methods all also exist non-surveyed area (Non-DetectionZone, NDZ) problem.When non-surveyed area generally betides and to there is coupling between electricity generation system and load, and when matching to a certain degree, no matter be all isolated island situation cannot be detected by active detection method or by passive type detection method.
Therefore, be necessary to provide a kind of system and method for improvement to solve above-mentioned technical problem.
Summary of the invention
Because above-mentioned technical problem, one aspect of the present invention is to provide a kind of energy conversion system.This energy conversion system comprises converter device and inverter controller.The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, and this inverter controller is configured for real component and the idle component of regulation output energy.This inverter controller comprises isolated island protection module, and this isolated island protection module is connected with the output electrical communication of this converter device.This isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produces isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement.This isolated island protection module be also configured to this isolated island disturbing signal and disturbance compensation signal function to become to regulate in this output energy in real component and idle component any one or all, the electrical parameter values of this measurement is shifted out outside critical field when there is isolated island situation.
In some embodiments, in the energy conversion system that this provides, this isolated island protection module comprises frequency change detecting unit, disturbance generation unit and compensating unit.This frequency change detecting unit is configured for the frequency signal receiving the phase-locked loop apparatus in this energy conversion system and obtain, and produces frequency variation signal based on this frequency signal.This disturbance generation unit is configured to receive this frequency variation signal, and produces this isolated island disturbing signal based on this frequency variation signal, so that the frequency values of this output energy is shifted out normal frequency range.This compensating unit and this disturbance generation unit are electrically connected, and this compensating unit is configured for and produces this disturbance compensation signal, for the unexpected variable quantity compensated caused by isolated island disturbing signal.
In some embodiments, in the energy conversion system provided, this isolated island disturbing signal comprises reactive current disturbing signal or reactive power disturbance signal.
In some embodiments, in the energy conversion system provided, this isolated island disturbing signal comprises reactive current disturbing signal and reactive power disturbance signal.
In some embodiments, in the energy conversion system provided, this disturbance compensation signal comprises q shaft voltage compensating signal.
In some embodiments, in the energy conversion system provided, this compensating unit is also configured to produce disturbance overcompensation signal.When there is isolated island situation, this this isolated island disturbing signal of disturbance overcompensation signal combination makes the frequency of this converter device output accelerate to shift out normal frequency range.
In some embodiments, in the energy conversion system provided, this isolated island protection module comprises frequency change rate detecting unit and dynamic gain adjustment unit further.This frequency change rate detecting unit is configured for and produces frequency change rate signal based on this frequency variation signal; This dynamic gain adjustment unit and this frequency change rate detecting unit are electrically connected, and this dynamic gain adjustment unit is configured to produce corresponding dynamic gain signal based on this frequency change rate signal.This dynamic gain signal is applied this disturbance generation unit, for the amplitude of the isolated island disturbing signal that this disturbance generation unit of dynamic conditioning produces.
In some embodiments, in the energy conversion system provided, this isolated island protection module comprises voltage change detection unit, disturbance generation unit and compensating unit.This voltage change detection unit is configured for the voltage signal receiving the voltage transformation module in this energy conversion system and obtain, and produces voltage change signal based on this voltage signal.This disturbance generation unit is configured to receive this voltage change signal, and produces this isolated island disturbing signal based on this voltage change signal, so that the magnitude of voltage of this output energy is shifted out normal voltage range.This compensating unit and this disturbance generation unit are electrically connected, and this compensating unit is configured for and produces this disturbance compensation signal, for the unexpected variable quantity compensated caused by isolated island disturbing signal.
In some embodiments, in the energy conversion system provided, this disturbance compensation signal comprises d shaft voltage compensating signal.
In some embodiments, in the energy conversion system provided, this compensating unit can also be configured to produce disturbance overcompensation signal.When there is isolated island situation, this this isolated island disturbing signal of disturbance overcompensation signal combination makes the voltage of this converter device output accelerate to shift out normal voltage range.
In some embodiments, in the energy conversion system provided, this isolated island protection module comprises voltage change ratio detecting unit and dynamic gain adjustment unit further.This voltage change ratio detecting unit is configured for and produces voltage change ratio signal based on this voltage change signal.This dynamic gain adjustment unit and this voltage change ratio detecting unit are electrically connected, this dynamic gain adjustment unit is configured to produce corresponding dynamic gain signal based on this voltage change ratio signal, this dynamic gain signal is applied this disturbance generation unit, for the amplitude of the isolated island disturbing signal that this disturbance generation unit of dynamic conditioning produces.
Another aspect of the present invention is to provide a kind of energy conversion system.This energy conversion system comprises converter device and inverter controller.The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, and this inverter controller is configured for real component and the idle component of regulation output energy.This inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this frequency variation signal measured by converter device output and frequency change rate signal, and at least produces isolated island disturbing signal and disturbance compensation signal according to the frequency variation signal of this measurement and frequency change rate signal.
Another aspect of the present invention is to provide a kind of energy conversion system.This energy conversion system comprises converter device and inverter controller.The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, and this inverter controller is configured for real component and the idle component of regulation output energy.This inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this voltage change signal measured by converter device output and voltage change ratio signal, and at least produces isolated island disturbing signal and disturbance compensation signal according to the voltage change signal of this measurement and voltage change ratio signal.
Another aspect of the present invention is to provide a kind of energy conversion system.This energy conversion system comprises converter device and inverter controller.The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, this inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component regulating this output energy, and this second control loop is configured to the idle component regulating this output energy.This inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement, this isolated island protection module is also configured to this isolated island disturbing signal is applied to this second control loop, to do disturbance to the idle component of this output energy.This isolated island protection module is also configured to this disturbance compensation signal function to this second control loop, the voltage instruction that this second control loop produces being compensated, keeping stable with the real component maintaining this first control loop when acting on this isolated island disturbing signal.
Another aspect of the present invention is to provide a kind of energy conversion system.This energy conversion system comprises converter device and inverter controller.The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, this inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component regulating this output energy, and this second control loop is configured to the idle component regulating this output energy.This inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produces isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement.This isolated island protection module is also configured to this isolated island disturbing signal to be applied to this first control loop, to do disturbance to the real component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this first control loop, the voltage instruction that this first control loop produces being compensated, keeping stable with the idle component maintaining this second servo loop when acting on this isolated island disturbing signal.
Another aspect of the present invention is to provide a kind of inverter controller, and it is configured for and controls converter device execution energy conversion operation.This inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement, this isolated island protection module be also configured to this isolated island disturbing signal and disturbance compensation signal function to become to regulate in this output energy in real component and idle component any one or all, the electrical parameter values of this measurement is shifted out outside critical field when there is isolated island situation.
Another aspect of the present invention is to provide a kind of inverter controller, and it is configured for and controls converter device execution energy conversion operation.This inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component of the output energy regulating this converter device to provide, and this second control loop is configured to the idle component of the output energy regulating this converter device to provide.This inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produces isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement.This isolated island protection module is also configured to this isolated island disturbing signal to be applied to this second control loop, to do disturbance to the idle component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this second control loop, the voltage instruction that this second control loop produces being compensated, keeping stable with the real component maintaining this first control loop when acting on this isolated island disturbing signal.
Another aspect of the present invention is to provide a kind of inverter controller, and it is configured for and controls converter device execution energy conversion operation.This inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component of the output energy regulating this converter device to provide, and this second control loop is configured to the idle component of the output energy regulating this converter device to provide.This inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produces isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement.This isolated island protection module is also configured to this isolated island disturbing signal is applied to this second control loop, to do disturbance to the idle component of this output energy.This isolated island protection module is also configured to this disturbance compensation signal function to this second control loop, the voltage instruction that this second control loop produces being compensated, keeping stable with the real component maintaining this first control loop when acting on this isolated island disturbing signal.
Another aspect of the present invention is to provide a kind of method for carrying out islanding detect to energy conversion system.The method at least comprises the steps: to receive this electrical quantity measured by energy conversion system output; At least produce isolated island disturbing signal and disturbance compensation signal based on this electrical quantity; Act on this isolated island disturbing signal, to shift out outside normal range (NR) when there is isolated island situation by this electrical quantity; And act on this disturbance compensation signal, to compensate the unexpected variable quantity caused by isolated island disturbing signal.
Another aspect of the present invention is to provide a kind of method for carrying out island protect to energy conversion system.The method at least comprises the steps: to receive this electrical quantity measured by energy conversion system output; At least produce isolated island disturbing signal and disturbance compensation signal based on this electrical quantity; Act on this isolated island disturbing signal, to shift out outside normal range (NR) when there is isolated island situation by this electrical quantity; Act on this disturbance compensation signal, to compensate the unexpected variable quantity caused by isolated island disturbing signal; And when the electrical quantity measured by this output is judged to be outside this normal range (NR), make this energy conversion system stop exporting energy.
Another aspect of the present invention is to provide a kind of photovoltaic energy conversion system.This photovoltaic energy conversion system comprises DC bus, photovoltaic converter and photovoltaic controller.This DC bus is configured for the direct current energy receiving photovoltaic energy source and provide.This photovoltaic converter is configured to convert the direct current energy at this DC bus place to AC energy.This photovoltaic controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this photovoltaic converter, this isolated island protection module is configured to receive this electrical parameter values measured by photovoltaic converter output, and at least producing isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement, this isolated island protection module is also configured to this isolated island disturbing signal to become with disturbance compensation signal function and the electrical parameter values of this measurement is shifted out outside critical field when generation isolated island situation.
In some embodiments, in the energy conversion system provided, this photovoltaic energy conversion system also comprises maximum power point tracking device, and this maximum power point tracking device is configured to produce direct voltage reference signal based on the photovoltaic voltage signal measured at this photovoltaic energy source place and photovoltaic current signal.Wherein, when there is isolated island situation, this this direct voltage reference signal of isolated island disturbing signal bypass.
Another aspect of the present invention is to provide a kind of photovoltaic energy conversion system.This photovoltaic energy conversion system comprises DC bus, photovoltaic converter and photovoltaic controller.This DC bus is configured for the direct current energy receiving photovoltaic energy source and provide.This photovoltaic converter is configured to convert the direct current energy at this DC bus place to AC energy.This photovoltaic controller comprises d axle control loop and q axle control loop, this d axle control loop is configured to regulate the real component in this photovoltaic converter output AC energy, and this q axle control loop is configured to regulate the idle component in this photovoltaic converter output AC energy.This photovoltaic controller also comprises isolated island protection module, and this isolated island protection module is connected with the output electrical communication of this photovoltaic converter.This isolated island protection module is configured to receive this electrical parameter values measured by photovoltaic converter output, and at least produces isolated island disturbing signal and disturbance compensation signal according to the electrical parameter values of this measurement.This isolated island protection module is also configured to this isolated island disturbing signal is applied to this d axle control loop, to do disturbance to the real component of this output energy.This isolated island protection module is also configured to by this disturbance compensation signal function to this d axle control loop, compensates the voltage instruction that this d axle control loop produces, and keeps stable with the idle component maintaining this q axle control loop when acting on this isolated island disturbing signal.
Energy conversion system provided by the invention, inverter controller, photovoltaic energy conversion system, islet operation detecting method, and islet operation guard method etc., disturbance is carried out by introducing the target electrical quantity of isolated island disturbing signal to energy conversion system output on one's own initiative, to facilitate, the islet operation situation of this energy conversion system is detected, and in the process introducing isolated island disturbing signal, by disturbance compensation signal dynamics, the unexpected variable quantity that isolated island disturbing signal causes is compensated, isolated island disturbing signal is made more effectively to carry out disturbance to target electrical quantity, to detect islet operation situation rapidly and accurately.In addition, in the mechanism of disturbing signal, by overcompensation mechanism, the movement of target electrical quantity can also be accelerated, to shorten the islanding detect time.Further, dynamic gain Regulation mechanism can also be passed through, the amplitude of dynamic conditioning isolated island disturbing signal, to accelerate islanding detect process and to maintain system stability.
Accompanying drawing explanation
Be described for embodiments of the present invention in conjunction with the drawings, the present invention may be better understood, in the accompanying drawings:
Figure 1 shows that the module diagram of a kind of execution mode of energy conversion system;
Figure 2 shows that the module diagram of a kind of execution mode of the photovoltaic energy conversion system of the isolated island protection module being configured with improvement;
Figure 3 shows that the detailed module diagram of a kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 4 shows that the detailed module diagram of a kind of execution mode of the current regulator shown in Fig. 3 and dynamic compensation unit;
Figure 5 shows that the detailed module diagram of a kind of execution mode of the current regulator shown in Fig. 3 and dynamic overcompensation unit;
Figure 6 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 7 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 8 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 9 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 10 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 11 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 12 shows that the detailed module diagram of a kind of execution mode of the current regulator shown in Figure 11 and dynamic compensation unit;
Figure 13 shows that the detailed module diagram of a kind of execution mode of the current regulator shown in Figure 11 and dynamic overcompensation unit;
Figure 14 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 15 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 16 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module shown in Fig. 2;
Figure 17 shows that the module diagram of the another kind of execution mode of the photovoltaic energy conversion system of the isolated island protection module being configured with improvement; And
Figure 18 shows that the flow chart of a kind of execution mode of islet operation detection or guard method.
Embodiment
One or more execution mode that the present invention discloses relates to energy conversion system, particularly active alone island detection method and can perform the energy conversion system of this active alone island detection method, to carry out detection and the protection of isolated island situation.Here so-called " active alone island detection method " refers to by having a mind to or introducing artificially or inject the control structure of a less disturbance quantity to system; break the equilibrium condition of system; one or more target electrical quantity of energy conversion system output is forced to change; be beneficial to the islet operation situation finding or detect system, and provide protection to system and load.Further, on the basis of active alone island detection method, the present invention proposes one " isolated island disturbance compensation mechanism " or " isolated island disturbance compensation algorithm " or " isolated island disturbance compensation method ", " isolated island disturbance compensation mechanism; algorithm or method " can effectively should eliminate or reduce usually to be present in traditional energy generating system, such as, non-detection zone in the distributed generation system having local load to connect by performing." the isolated island disturbance compensation mechanism; algorithm or method " here mentioned refers to a kind of controlling mechanism or control algolithm, it can produce corresponding disturbance compensation signal based on isolated island disturbing signal in the process performed, and by the control loop of this disturbance compensation signal function to system, to eliminate, offset or reduce the unexpected variable quantity because effect isolated island disturbing signal causes.Such as, this unexpected variable quantity can be unexpected meritorious variable quantity, and this unexpected meritorious variable quantity may be due to after such as q axle control loop introduces reactive current or reactive power disturbance signal, and produce at d axle control loop.In traditional energy conversion system or distributed generation system, if not unexpected to this variable quantity compensates, this unexpected variable quantity can slow down the disturbance of isolated island disturbing signal to target electrical quantity in the reverse direction, thus the detection of isolated island disturbance is become be not so effective." the isolated island disturbing signal " here mentioned may also be referred to as perturbation signal, it is a small-signal, is introduced into or is injected in the control loop of system, under the prerequisite not affecting the normal power generation the output of process quality of power supply, change one or more electrical quantity of energy conversion system output (such as, voltage, frequency, phase place, impedance, harmonic wave, active power and/or reactive power etc.), thus more easily detect isolated island situation when electrical network departs from energy conversion system.
In some embodiments, produced and the disturbance compensation signal acted on by this " isolated island disturbance compensation mechanism ", can offset or eliminate the unexpected variable quantity caused by isolated island disturbing signal exactly well.In other embodiments, this disturbance compensation signal can be produced by specific mode and act on, it not only eliminates unexpected variable quantity, and positive feedback effect can be played to the movement of target electrical quantity, also namely, be consistent with the disturbance effect of isolated island disturbing signal, accelerate the movement of target electrical quantity, to make target electrical quantity can shift out normal threshold range more quickly, such compensation way also can be called " isolated island disturbance overcompensation mechanism ".
Further, in some embodiments, as can in an alternative manner or on the basis of " the isolated island disturbance compensation mechanism " of foregoing description, this energy conversion system can also perform " dynamic gain Regulation mechanism ", when connecting to depart from electrical network, detect islet operation situation faster.Refer in the production process of isolated island disturbing signal at this so-called " dynamic gain Regulation mechanism ", the dynamic or adjustable yield value of the rate of change effect one according to observed target electrical quantity.Referred in this " dynamic or adjustable yield value " can be a continuous print variable (be also, a corresponding target electrical quantity rate of change value of yield value), also can be a discrete variable (also namely, a corresponding one section of target electrical quantity rate of change value of yield value or corresponding multiple target electrical quantity rate of change value).For example, when the stage injects isolated island disturbing signal in early days, the rate of change of target electrical quantity may be smaller, now can act on a relatively large yield value, to accelerate the skew of target electrical quantity; And when mid-term or later stage injecting isolated island disturbing signal, because the rate of change possibility of this target electrical quantity is relatively large under the effect of positive feedback, now suitably can reduce yield value, to maintain the stable of system.
Carry out detection and the protection of islet operation situation by performing " isolated island disturbance compensation mechanism " proposed by the invention, the present invention at least can obtain the technological merit or technique effect that reduce non-detection zone.By reducing non-detection zone, islanding detect can be made to become more reliable and accurately, provide better safety guarantee also can to the personnel performing working service, also can avoid the impact damage because power system restoration DC-to-AC converter suffers simultaneously.In addition, owing to can eliminate or reduce unexpected variable quantity by performing " isolated island disturbance compensation mechanism ", therefore can introduce relatively little disturbing signal and carrying out islanding detect, reducing disturbing signal to the technique effect of systematic influence to obtain.Further technique effect or technological merit are: by performing disturbance overcompensation mechanism, or dynamic gain Regulation mechanism, or it combines, and can shorten the detection time of isolated island situation.
One or more embodiment of the present invention below will be described.First it is to be noted, in the specific descriptions process of these execution modes, in order to carry out brief and concise description, this specification can not all do detailed description to all features of the execution mode of reality.Should be understandable that; in the actual implementation process of any one execution mode; as in the process of any one engineering project or design object; in order to realize the objectives of developer; or in order to meet that system is correlated with or that business is relevant restriction; usually can make various concrete decision-making, and this also can change to another kind of execution mode from a kind of execution mode.In addition, it will also be appreciated that, although effort done in this development process may be complicated and tediously long, but for those of ordinary skill in the art relevant to content disclosed by the invention, some designs that the basis of the technology contents of disclosure exposure is carried out, manufacture or production etc. changes just conventional technological means, not should be understood to content of the present disclosure insufficient.
Unless otherwise defined, the technical term used in the present specification and claims or scientific terminology should be in the technical field of the invention the ordinary meaning that the personage with general technical ability understands." first " or " second " that use in this specification and claims and similar word do not represent any order, quantity or importance, and are only used to distinguish different parts.The similar word such as " one " or " one " does not represent restricted number, but represents to there is at least one." or " comprise in cited project any one or all." comprise " or the similar word such as " comprising " mean to appear at " comprising " or " comprising " before element or object contain the element or object and equivalent element thereof that appear at " comprising " or " comprising " presented hereinafter, do not get rid of other elements or object." connection " or " being connected " etc. similar word be not defined in physics or the connection of machinery, no matter but can comprise electrical connection, be direct or indirectly.In addition, the set that " circuit " or " Circuits System " and " controller " etc. can comprise single component or directly or be indirectly connected by multiple active member or passive device, such as one or more integrated circuit (IC) chip, to provide the corresponding function described.
Figure 1 shows that the outline module diagram of a kind of execution mode of the energy conversion system 10 that the present invention discloses.In the illustrated embodiment, this energy conversion system 10 roughly comprises converter device 14, this converter device 14 is configured to convert the first electric energy 121 obtained from energy source 12 to second electric energy 141, and this second electric energy 141 is supplied to load 19 and/or electrical network 16.This first electric energy 121 can be direct current energy, and such as, this direct current energy can be produced by devices such as such as photovoltaic panels; This first electric energy 121 also can be AC energy, and such as, this AC energy can be produced by devices such as such as wind turbines.In other embodiments, this is used for providing the energy source 12 of the first electric energy 121 to be the distributed power generation unit of any type, includes but not limited to, fuel cell, storage battery, Microturbine, water turbine, tidal energy turbine etc.When the first electric energy 121 is direct current energy, this converter device 14 can be configured to the converter structure of the converter structure of single-stage or twin-stage (such as, DC-AC current transformer and AC-DC current transformer), direct current energy can be converted to the AC energy with specific voltage and frequency when operating by it, carry with power supply network 16, and/or consume for local load 19.When the first electric energy 121 is AC energy, this converter device 14 also can be configured to the converter structure of the converter structure of single-stage or twin-stage (such as, AC-DC current transformer and DC-AC current transformer), it can perform the map function exchanged to exchanging when operating, to provide the AC energy power supply network 16 of suitable voltage and frequency to carry, and/or consume for local load 19.
In the illustrated embodiment, this energy conversion system 10 can also comprise inverter controller 18, this inverter controller 18 can be configured to communicate to connect with the output of this converter device 14, with one or more electrical parameter values measured by the output being received in this converter device 14 (such as, voltage, frequency, phase place, impedance, harmonic wave, active power, and/or reactive power), these electrical quantitys can be obtained by one or more transducer (not shown in figure 1) measurement or be calculated by the data measured.In some embodiments, can between converter device 14 and electrical network 16 on connection line any selection a bit measure these electrical quantitys.Especially, in specific execution mode, the position 143 being commonly referred to as points of common connection (PointofCommonCoupling, PCC) can be selected to carry out the measurement of electrical quantity.After the signal of telecommunication 142 measured by obtaining, in conjunction with one or more instruction or reference signal, this inverter controller 18 can perform one or more control algolithm or controlling mechanism, and transmit control signal 182 (such as based on execution result, control the switching signal of semiconductor switch device in converter device 14) to converter device 14, control the running of converter device 14, and then one or more electrical parameter values of converter device 14 output is regulated.More specifically, this inverter controller 18 can be configured to execution first controlling mechanism (such as, d axle control loop), to regulate the active power of converter device 14 output, or regulate the direct voltage at converter device 14 input DC bus place.This inverter controller 18 can also be configured to execution second controlling mechanism (such as, q axle control loop), to regulate the reactive power of converter device 14 output.In specific execution mode, this first controlling mechanism and this second controlling mechanism can carry out uneoupled control, to realize controlling the independence of active power and reactive power.
Please continue to refer to Fig. 1, this inverter controller 18 can comprise islanding detect module or isolated island protection module 180, this isolated island protection module 180 can be performed by inverter controller 18, with electrical network tripping operation or with energy conversion system 10 disconnect be electrically connected time, the islet operation situation of detected energy converting system 10, and when determining that energy conversion system 10 operates in isolated island situation really, interrupt the Power supply to load 19 and/or electrical network 16.In a particular embodiment, this isolated island protection module 180 can be presented as one section of computer program, this computer program can comprise some the program command that can be performed by computer, and this program command can be stored in the storage device of non-momentary (non-transitory), for reading and execution; This isolated island protection module 180 also can be presented as one piece of hardware circuit, and this hardware circuit can comprise multiple interconnective electronic device, and it is configured to perform islanding detect function and provide corresponding defencive function equally.In the illustrated embodiment, this isolated island comprises module 180 can be the same with the second controlling mechanism as other first controlling mechanisms, is arranged on inverter controller 18 inside and performs, and form a single device.In other embodiments, this isolated island protection module 180 also should can be configured to relative inverter controller 180 independently device.
Please continue to refer to Fig. 1, in one embodiment, the isolated island protection module 180 shown in Fig. 1 is also configured to produce isolated island disturbing signal and disturbance compensation signal.This isolated island disturbing signal can according to the variable quantity of one or more electrical quantity measured by converter device 14 output (such as, frequency change and/or change in voltage) produce, and this isolated island disturbing signal can act in the control loop in inverter controller 18, to change one or more command signal in this control loop or reference signal, thus change one or more electrical parameter values of this converter device 14 output, to facilitate the detection of islet operation situation.For example, this isolated island disturbing signal can be q axle reactive current disturbing signal, and it is used to the command signal revising reactive current, and then changes the reactive power exported, thus causes the frequency of output to change.But, due to the impact of the cross-coupling mechanisms between controlled loop, such as, cross coupling effect between d axle control loop and q axle control loop, the active power that the q axle reactive current disturbing signal injected can cause converter device 14 to export simultaneously changes, the change of this unexpected active power makes the frequency change exported can not reach the numerical value of expectation, thus makes disturbance become effective not.For addressing this problem, in one embodiment, injecting the process of isolated island disturbing signal, produce a disturbance compensation signal simultaneously, and this disturbance compensation signal is acted in some way in the control loop in current transformer control 18, to avoid or to reduce the active power variation because isolated island disturbing signal such as reactive current disturbing signal causes as far as possible.Certainly, in other embodiments, this disturbance compensation signal also can be produced by specific mode and be applied in the control loop in inverter controller 18, such as, this disturbance compensation signal can be overcompensation signal, and this overcompensation signal carries out disturbance with the type of action identical with isolated island disturbing signal to target electrical quantity, under the effect of positive feedback, rapidly target electrical quantity is disturbed out normality threshold scope, to realize the detection of islet operation situation.
Figure 2 shows that the module diagram of a kind of execution mode of the photovoltaic energy conversion system 20 that the present invention discloses.Although, in this embodiment, photovoltaic energy conversion system 20 is by as specific example, the island detection method of the improvement that the present invention relates to or algorithm are described in detail, but, therefore and by protection scope of the present invention photovoltaic art should be only limited to, this area is had to the personnel of usual knowledge, by in the island detection method of this improvement disclosed or algorithm application to the energy conversion system or distributed generation system of other types, such as fuel cell generation, in wind generator system and waterpower or tidal power system, should also be feasible.As shown in Figure 2, this photovoltaic energy conversion system 20 roughly comprises photovoltaic converter device 24, this photovoltaic converter device 24 is configured to convert the direct current energy provided by photovoltaic energy source 22 AC energy with appropriate voltage and frequency to, carry with power supply network 34, and/or consume for local load 36.In one embodiment, this photovoltaic energy source 420 can comprise one or more photovoltaic array, wherein each photovoltaic array comprises again the multiple photovoltaic cells interconnected, and converts solar radiant energy to direct current energy for according to photoelectric effect.
In one embodiment, this photovoltaic converter device 24 shown in Fig. 2 is based on the framework of two-stage type, it comprises photovoltaic side converter 26 (also namely near the current transformer of side, photovoltaic energy source 22) and net side converter 32 (also namely near the current transformer of electrical network 34 side, also referred to as net side inverter).This photovoltaic side converter 26 can comprise DC-DC converter, such as Boost DC-DC convertor, and it can raise the direct voltage being changed output by photo-voltaic power supply 22, and the direct voltage after raising is supplied to DC bus 28.This DC bus 28 can comprise one or more capacitor, and the magnitude of voltage in order to the direct voltage by DC bus 28 maintains specific numerical value, thus can control the energy flow from DC bus 28 to electrical network 34.This net side converter 32 can comprise DC-AC current transformer, in order to the direct voltage at DC bus 28 place to be converted to the alternating voltage that applicable AC network 34 is carried.For convenience of describing, the photovoltaic energy conversion system 20 shown in Fig. 2 illustrate only the connecting line be connected between net side converter 32 and electrical network 34, for exemplarily representing single-phase current signal and the measurement of voltage signal.Be understandable that, the photovoltaic energy conversion system 20 disclosed at this can be applied to the occasion with multiple connected mode, includes but not limited to three-phase connection system and/or heterogeneous connection system.In addition, between this net side converter 32 and electrical network 34, can further include net side filter 154.This net side filter 154 comprises one or more capacitive element and inductive element, the harmonic component the alternating current exported from net side converter 32 in order to filtering or alternating voltage.Although do not do further signal in fig. 2, this photovoltaic energy conversion system 20 should comprise one or more other elements according to the application of reality, include but not limited to, transformer, contactor, circuit breakers etc., these elements can be configured and be connected between this net side converter 32 and electrical network 34.
In one embodiment, photovoltaic energy conversion system 20 shown in Fig. 2 comprises photovoltaic converter control system 38 further, this photovoltaic converter control system 38 is by performing specific controlling mechanism or control algolithm, based on various feedback signal and command signal, the running of Controling network side converter 32.More specifically, this photovoltaic converter control system 38 comprises current transformation unit 164, and this current transformation unit 164 receives the current signal 162 measured by current sensor 152 (being placed between net side converter 32 and load 36 or electrical network 34).In one embodiment, this current transformation unit 164 performs the coordinate transform operation under static coordinate system to rotating coordinate system, the current signal 162 of measurement is transformed into the d axis current signal 216 under rotating coordinate system and q axis current signal 218.This d axis current signal 216 and q axis current signal 218 are transmitted to current regulator 208 to regulate electric current.
In one embodiment, this photovoltaic converter control system 38 shown in Fig. 2 also comprises voltage transformation module 166, and this voltage transformation module 166 has the structure similar with current transformation unit 164, and performs corresponding voltage-converting operation.In interchangeable execution mode, also can configure single converter unit, the coordinate transform operation making it simultaneously perform voltage and current.This voltage transformation module 166 receives the voltage signal 158 measured by voltage sensor 156 (being placed between net side converter 32 and load 36 or electrical network 34).In one embodiment, this voltage transformation module 166 performs the coordinate transform operation under static coordinate system to rotating coordinate system, the voltage signal 158 of measurement is transformed into the d shaft voltage signals 175 under rotating coordinate system and q shaft voltage signals 174.About the detail of the coordinate transform operation under static coordinate system to rotating coordinate system, for this area has known by the personnel of general knowledge, therefore will not be described in detail it in present embodiment.
In the embodiment shown in figure 2, the q shaft voltage signals 174 produced by voltage transformation module 166 is transmitted to phase-locked loop apparatus 168, for generation frequency signal or angular frequency signal 176.Phase-locked loop apparatus 168 is generally used for following the trail of the frequency of electrical network and phase place, and it can be performed by traditional hardware or software service, and the detailed construction therefore about phase-locked loop apparatus 168 is not also described in detail in the present embodiment.In the illustrated embodiment, this d shaft voltage signals 175 and frequency signal 176 are transmitted to isolated island protection module 172 (with isolated island protection module 180 described in conjunction with Figure 1 is similar) above.In one embodiment, this d shaft voltage signals 175 and frequency signal 176 are two kinds of reflection output electrical quantity, and it is used for assessing photovoltaic energy conversion system 20 especially and whether operates in island state.For example, when assessed electrical quantity exceedes default normal range (NR) threshold value (such as, exceed upper limit threshold, or lower than lower threshold), then think that this photovoltaic energy conversion system 20 is in island operation state.In other embodiments, except frequency signal and voltage signal, the parameter signal of other types, such as phase place, impedance, harmonic wave etc. also can be used to separately or whether this photovoltaic energy conversion system 20 of evaluation that combines operates in island state.In one embodiment, when this frequency signal 176 and this d shaft voltage signals 175 be judged as do not violate default islet operation rule time, also be, this frequency signal 176 and this d shaft voltage signals 175 are within default normality threshold scope, and this isolated island protection module 172 can be configured to produce isolated island disturbing signal 178 and disturbance compensation signal 184 according to the combination of this frequency signal 176 or this d shaft voltage signals 175 or these two kinds of signals.Once judge that photovoltaic energy conversion system 20 operates in island state, island protect function can be started, by load 36 and/or electrical network 34 isolated with photovoltaic energy conversion system 20.
In one embodiment, this isolated island protection module 172 produce isolated island disturbing signal 178 and disturbance compensation signal 184 be applied in the first controlling mechanism 185 or the second controlling mechanism 187.More specifically, this first controlling mechanism 185 comprises d axle control loop, and this second controlling mechanism 187 comprises q axle control loop.This d axle control loop 185 comprises direct current voltage regulator 194, and it is configured to receive the direct voltage command signal 192 that the direct voltage feedback signal 188 that measured by direct current voltage sensor 186 and representative are desirably in the direct voltage that DC bus 28 place obtains.This direct current voltage regulator 194 produces d shaft current command signal 196 according to this direct voltage feedback signal 188 and this direct voltage command signal 192.This q axle control loop 187 comprises voltage-Reactive-power control device 198, it is configured to the idle command signal 204 and the idle feedback signal 202 that receive the reactive power that representative obtains desired by net side converter 32 output, and the signal received is made adjustments, to produce q shaft current command signal 206.Idle feedback signal 202 current signal 162 that can obtain according to above-mentioned measurement and voltage signal 158 calculate referred in this.
In the embodiment shown in figure 2, this first control loop 185 is connected with current regulator 208 with this second control loop 187, this current regulator 208 is configured to the d shaft current command signal 196 that reception direct current voltage regulator 194 provides, the q shaft current command signal 206 that voltage-Reactive-power control device 198 provides, and the d shaft current feedback signal 216 that provides of current transformation unit 164 and q shaft current feedback signal 218.This current regulator 208, according to the d axle received and q shaft current feedback signal and command signal, carries out Current adjustment, to produce d shaft voltage command signal 212 and q shaft voltage command signal 214.This d shaft voltage command signal 212 and q shaft voltage command signal 214 are provided to coordinate transform and modulating unit 138, according to the frequency signal 176 that phase-locked loop apparatus 168 provides, received d shaft voltage command signal 212 and q shaft voltage command signal 214 are rotated back to the voltage signal rest frame by this coordinate transform and modulating unit 138 from d-q reference frame, and use the signal after conversion to modulate carrier signal, to produce the control signal 182 for net side converter 32.In order to simplify, Fig. 2 uses single module 138 to show coordinate transform function and modulation function, in other embodiments, two modules can be used to realize this two functions respectively.Below how detailed description isolated island protection module 172 is produced isolated island disturbing signal 178 and disturbance compensation signal 184, and how this isolated island disturbing signal 178 and disturbance compensation signal 184 are applied in control loop 185 and 187.
Fig. 3 to Figure 10 shows several execution modes of the isolated island protection module 172 shown in Fig. 2, wherein, the isolated island disturbing signal 178 that this isolated island protection module 172 produces is applied in q axle control loop or idle control loop 187, and this disturbance compensation signal 184 is applied into elimination or alleviates the negative effect owing to injecting caused by isolated island disturbing signal 178.
Figure 3 shows that the detailed module diagram of a kind of execution mode of the isolated island protection module 172 shown in Fig. 2.In the illustrated embodiment, this isolated island protection module 172 comprises frequency change detecting unit 222 and disturbance generation unit 226.This frequency change detecting unit 222 is connected with this phase-locked loop apparatus 168, to receive the frequency signal 176 that this phase-locked loop apparatus 168 produces.In one embodiment, this frequency variation unit 222 is configured to judge whether the frequency signal 176 of this reception departs from normal frequency values (such as, 60Hz or 50Hz).More specifically, this frequency signal 176 can be compared with normal frequency values by this frequency change detecting unit 222, and draws frequency departure signal 224.In one embodiment, this frequency departure signal 224 is provided to disturbance generation unit 226, with generation current disturbing signal 228.
In one embodiment, this current disturbing signal 228 comprises q shaft current disturbing signal 228, and this q shaft current disturbing signal 228 can be produced by the gain suitable to the frequency departure signal function provided by frequency change detecting unit 222 one.This q shaft current disturbing signal 228 is applied in q axle control loop 187, to revise q shaft current command signal 238.In the execution mode shown in Fig. 3, this q shaft current disturbing signal 228 carries out amplitude restriction through the first clipping unit 232.Then the q shaft current disturbing signal 228 of this restriction is provided to summator 236, to revise q shaft current command signal 238, and obtains that revise or after disturbance q shaft current command signal 242.In another execution mode, unrestriced q shaft current disturbing signal 228 also can be used to revise or disturbance q shaft current command signal 238.After the q shaft current command signal 242 of this amendment is carried out amplitude restriction by the second clipping unit 244, be transmitted to current regulator 208, to carry out Current adjustment.In interchangeable execution mode, the q shaft current command signal 242 of this amendment also directly can be given current regulator 208 and be carried out Current adjustment, and produces d shaft voltage command signal 212 and q shaft voltage command signal 214.
Please continue to refer to Fig. 3, in one embodiment, this isolated island protection module 172 comprises disturbance compensation unit 248 further, for generation disturbance compensation signal 252.This disturbance compensation signal 252 for compensating owing to introducing q shaft current disturbing signal 228 or 234, in the unexpected change that d axle control loop 185 occurs.Do not exist under disturbing signal or steady state situations, the active power of net side converter 32 output and reactive power can pass through following equation expression:
P inv=1.5 (V di d+ V qi q) formula (1),
Q inv=1.5 (V qi d-V di q) formula (2),
Wherein, in formula (1) and formula (2), V dand V qbe respectively the d shaft voltage component of output voltage under d-q rotating coordinate system and q shaft voltage component, I dand I qbe respectively the d shaft current component of output current under d-q rotating coordinate system and q shaft current component, V invand Q invbe respectively active power and the reactive power of net side converter 32 output.Passable according to formula (2), the reactive power that the current disturbing Δ I that superposition one is little on the basis of q shaft current command signal 238 can cause net side converter 32 to export changes.In addition, reactive power also can be expressed by following formula (3):
Q inv = V inv 2 ( 1 ωL - ωC ) Formula (3),
Wherein, V invfor the output voltage of net side converter 32, ω is the output frequency of net side converter 32, L with C is respectively inductance value and the capacitance of the local load be connected with net side converter 32.According to formula (3), the change of reactive power can cause the output of net side converter 32 to produce frequency change Δ ω, this frequency change Δ ω is used for generation current disturbance Δ I further, this current disturbing has the symbol identical with frequency change, disturbance is so made to operate in the mode of positive feedback, thus the accumulation that the frequency change of each time is continued in one direction, finally make the frequency exported be disturbed out outside normal frequency range.In one embodiment, this normal scope is configured to have a higher limit and a lower limit.In interchangeable execution mode, for some other electrical quantity, this normal scope only can have a higher limit or only have a lower limit.In normal operation; when electrical network 34 is connected with net side converter 32; frequency due to electrical network is enough stable the frequency of output substantially to be remained unchanged or only have the fluctuation of little Fu but can not trigger the relevant action of island protect; therefore the frequency disturbance caused by isolated island disturbing signal can due to the regulating action of electrical network; and accumulation can not be continued in one direction, thus do not affect the output of normal electric energy.But, when electrical network tripping operation or with photovoltaic energy conversion system 20 lose be electrically connected time, electrical network loses the control to photovoltaic energy conversion system 20 output frequency, therefore, the frequency change Δ ω caused by Injection Current disturbance Δ I can continue accumulation, thus can shift out outside normal frequency range by output frequency the most at last.In this case, islet operation situation can be detected, and corresponding operation can be started, such as, open the switch be connected between net side converter device 32 and local load 36, local load 36 is kept apart with net side converter device 32, or net side converter device 32 is closed, to cut off the Power supply to local load 36.
By formula (3), when action current disturbing signal, more satisfactory situation is that the voltage maintaining net side converter 32 output remains unchanged, to make reactive power only relevant with frequency.But when the unexpected variable quantity do not caused acted on isolated island disturbing signal does any compensation, usually things turn out contrary to one's wishes.More specifically, when q shaft current disturbing signal 228 or 234 is applied q axle control loop, the active power of this net side converter 32 output can be expressed as follows:
P inv_dis=P inv+ Δ P formula (4),
Δ P=1.5 (I q+ Δ I q) Δ V qformula (5),
Wherein, in formula (4) and formula (5), Δ I qfor q shaft current disturbing signal, Δ V qfor effect q shaft current disturbing signal Δ I qcaused q shaft voltage change, P inv_disfor the active power of net side converter 32 output after disturbance, Δ P is effect q shaft current disturbing signal Δ I qcaused active power change.As can be seen from formula (4) and (5), introduce q shaft current disturbing signal, not only make the reactive power of output change, less desirable active power can be caused simultaneously to change.Because active power also can be expressed as follows:
P inv = V inv 2 R Formula (6),
Wherein, in formula (6), V invfor the output voltage of net side converter 32 output, R is the resistance value of the local load be connected with net side converter 32 output.In order to solve above-mentioned unexpected active power variation issue, in one embodiment, the active power change caused by the q shaft current disturbing signal 228 injected by effect voltage compensation signal, can make final q shaft voltage changes delta V qvanishing.Therefore, the output frequency of this net side converter 32 output can be changed more effectively by introducing q shaft current disturbing signal, and not by the impact of unexpected active power.
This disturbance compensation signal 252 produced by this disturbance compensation unit 248 in one embodiment comprises q shaft voltage compensating signal 252.In one embodiment, this q shaft voltage compensating signal 252 carries out amplitude restriction by clipping element 254, and this voltage signal 256 through amplitude restriction is transmitted to summator 258.Q shaft voltage command signal 214 and q shaft voltage compensating signal 256 are added by this summator 258, to produce the q shaft voltage command signal 262 after compensation.
Please consult Fig. 4 further, it is depicted as the module diagram of a kind of execution mode of the element at least comprising the dynamic compensation unit 248 shown in Fig. 3 and current regulator 208.This current regulator 208 comprises d shaft current adjuster 227, it is configured to regulate according to d shaft current deviation signal 225, to produce d shaft voltage command signal 229, wherein, this d shaft current deviation signal 225 is obtained by d shaft current command signal 196 and d shaft current feedback signal 216 being subtracted each other by summator 223.This d shaft voltage command signal 229 is transmitted to summator 230, and summed element 230 is used for subtracting each other with the voltage signal 231 at least calculated by q shaft current feedback signal 218 and impedance 235, to produce d shaft voltage command signal 233.This current regulator 208 comprises q shaft current adjuster further, it is configured to regulate according to q shaft current deviation signal 239, to produce q shaft voltage command signal 243, wherein, this q shaft current deviation signal 239 by summator 237 by the combination of q shaft current command signal 206 and q shaft current disturbing signal 228 or 234 and q shaft current feedback signal 218 are subtracted each other and are obtained.This q shaft voltage command signal 243 is transmitted to summator 258, this summator 258 receives the voltage signal 249 at least calculated by d shaft current feedback signal 216 and impedance 247, also receive q shaft voltage compensating signal 259, and to the signal summation received, the q shaft voltage command signal 251 after being compensated.
In the execution mode shown in Fig. 4, this dynamic compensation unit 248 comprises q axle compensated regulator 253 and unit 257 of negating.This q axle compensated regulator 253 can by acting on a gain, to obtain q shaft voltage compensating signal 255 to received q shaft current disturbing signal 228 or 234.This q shaft voltage compensating signal 255 is negated after unit 257 negates, its negate after voltage compensation signal 259 be used to compensate the unexpected voltage signal caused by the q shaft current disturbing signal 228 or 234 acted at q axle control loop 187.In one embodiment, this negate after voltage compensation signal 259 voltage signal unexpected with this be added after be zero substantially.Also namely, even if make the active power of net side converter 32 output when there being the disturbing signal effect of q shaft current by voltage compensation mechanism, still substantially remain unchanged.Therefore, the target electrical quantity of this net side converter 32 output, such as, frequency, can only be correlated with q shaft current disturbing signal 228 or 234.When electrical network lose or depart from and the electrical connection of photovoltaic energy conversion system 20 time, the frequency of this net side converter 32 output within the scope of official hour (such as, two seconds), can be shifted out outside normal frequency range more rapidly.Then, can detect that this photovoltaic energy conversion system 20 operates in isolated island situation, and carry out correspondingly protection act, such as, net side converter 32 be closed, stop supply electric energy to local load 19.
Please consult Fig. 5 further, it is depicted as the module diagram of the another kind of execution mode of the element at least comprising the dynamic compensation unit 248 shown in Fig. 3 and current regulator 208.Element shown in Fig. 5 is basic and the element shown in Fig. 4 is similar.Especially, in Figure 5, this dynamic compensation unit 248 is configured to have overcompensation function, or is called dynamic overcompensation unit.This dynamic overcompensation unit 248 comprises q axle compensated regulator 253 and gain unit 261.This q axle compensated regulator 253 produces voltage compensation signal 255 according to q shaft current disturbing signal 228 or 234.This gain unit 261 is connected with this q axle compensated regulator 253, gives this voltage compensation signal 255, to produce q shaft voltage overcompensation signal 263 with action gain COEFFICIENT K.In one embodiment, this gain coefficient K can be regulated according to the situation of reality, to adjust the overcompensation degree to target electrical quantity that q shaft voltage overcompensation signal 263 can provide.By voltage overcompensation mechanism, the target electrical quantity of net side converter 32 output, such as output frequency, can be moved out of outside normal frequency range more rapidly, therefore, can shorten the detection time of isolated island situation.In other embodiments, this dynamic compensation unit shown in Fig. 4 and Fig. 5 or this dynamic overcompensation unit 248 can also comprise the element of one or more other functions, such as, one or more filter element, be applied before paired voltage instruction compensates at compensating signal 259 or overcompensation signal 263, perform filtering operation.
Figure 6 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2, wherein, this execution mode is also by increasing dynamic gain adjustment function to adjust the amplitude of isolated island disturbing signal.More specifically, in one embodiment, this isolated island protection module 172 comprises frequency change rate detecting unit 298 and dynamic gain adjustment unit 304 further.This frequency change rate detecting unit 298 is connected with this frequency change detecting unit 222, with receive frequency deviation signal 224, and produces frequency change rate signal 302 according to frequency departure signal 224.This dynamic gain adjustment unit 304 is configured to be connected with this frequency change rate detecting unit 298, with receive frequency rate of change signal 302, and produces the gain signal 306 of following this frequency change rate signal 302 dynamic change.In the process detecting isolated island situation, early stage frequency (such as, electrical network departs from the frequency connecting the rear incipient stage) may with less rate of change in change, therefore, in order to accelerate the movement of frequency, to carry out the detection of isolated island situation easily and fast, increasing disturbance quantity that can be suitable, to reach this object.In this case, gain signal 306 can be adjusted, and be applied to current disturbing generation unit 226 to produce the current disturbing signal 228 with higher magnitude.Under another situation, along with the effect of current disturbing signal 228, and under positive feedback effect, in the middle and later periods of disturbance, the frequency of this net side converter 32 output can have larger rate of change.In order to maintain the stable of system, gain signal 306 can be adjusted to less numerical value according to this larger frequency change rate by this dynamic gain adjustment unit 304, suitably to reduce produced current disturbing signal 228.
Figure 7 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2.In the illustrated embodiment, to carry out isolated island condition detection different from use q shaft current disturbing signal mentioned above, this isolated island protection module 172 comprises reactive disturbance generation unit 308, and this reactive disturbance generation unit 308 is configured to produce reactive disturbance signal 312 according to frequency variation signal 224.This reactive disturbance signal 312 or the reactive disturbance signal 314 after the first clipping unit 232 carries out amplitude restriction are transmitted to summator 316, this reactive disturbance signal 312 or 314 is added with reactive power command signal 204 by this summator 316, to modify or disturbance to idle command signal 204, obtain amended idle command signal 318.This is transmitted to voltage-Reactive-power control device 198 through amended idle command signal 318, and it regulates according to idle feedback signal 202 (see Fig. 2) and voltage feedback signal etc., produces q shaft current command signal 322.This q shaft current command signal 322 is after the second clipping element 244 carries out amplitude restriction, and the q shaft current command signal 324 after its restriction produced is transmitted to current regulator 208 and regulates.In interchangeable execution mode, also can directly send the q shaft current command signal 322 limited without amplitude to current regulator 208 and regulate.Further, in the illustrated embodiment, this dynamic compensation unit 248 uses this reactive disturbance signal 312 or 314 to produce voltage compensation signal 252.The q shaft voltage command signal 214 that this voltage compensation signal 252 is used to current regulator 208 provides is modified or compensates, and changes in the unexpected active power that d axle produces to offset or reduce owing to introducing reactive disturbance signal 312 or 314 at q axle control loop 187.The structure of the dynamic compensation unit 248 shown in Fig. 7 and the dynamic compensation unit shown in Fig. 4 and Fig. 5 similar, also can be configured to that there is dynamic overcompensation function equally.
Figure 8 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2, wherein, frequency change rate detecting unit 298 is used to the rate of change detecting frequency.This isolated island protection module 172 also comprises dynamic gain adjustment unit 304, and it is used to produce gain signal 306 according to detected frequency change rate.Similarly, this gain signal 306 is applied this reactive disturbance generation unit 308, with the amplitude of dynamic conditioning reactive disturbance signal 312.
Figure 9 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2.This isolated island protection module 172 comprises compound disturbing signal generation unit 326, for the multiple disturbing signal of generation.In one embodiment, the frequency departure signal 224 of this compound disturbing signal generation unit 326 detected by frequency change detecting unit 222 produces q shaft current disturbing signal 328 and reactive disturbance signal 332.This q shaft current disturbing signal 328 and this reactive disturbance signal 332 can carry out corresponding amplitude restriction through the first clipping unit 334, and the q shaft current disturbing signal 336 after restriction and reactive disturbance signal 338 are transmitted to the first summator 236 and the second summator 316 respectively, to revise respectively or disturbance q shaft current command signal 344 and idle command signal 204.Further, this isolated island protection module 172 also comprises dynamic compensation unit 248, and it produces q axle disturbance compensation signal 252 according to this q shaft current disturbing signal 328 or 336 and reactive disturbance signal 332 or 338.This q axle disturbance compensation signal 252 is after the 3rd clipping element 254 carries out amplitude restriction, q axle disturbance compensation signal 256 after its restriction is transmitted to summator 258, with amendment or compensate q shaft voltage instruction 214, thus offset or reduce the unexpected active power change that produces at d axle owing to introducing q shaft current disturbing signal 328 or 336 and reactive disturbance signal 332 or 338 at q axle control loop 187.
Figure 10 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2, wherein, this isolated island protection module 172 also comprises dynamic gain Regulation mechanism.More specifically, the gain signal 306 produced by dynamic gain adjustment unit 304 can have larger numerical value in disturbing signal mechanism in early days, make compound disturbing signal generation unit 326 can produce q shaft current disturbing signal 328 and the reactive disturbance signal 332 of bigger numerical according to this gain signal 306, with the target electrical quantity that this can will export, such as, the frequency of net side converter 32 output disturbs out normal frequency range fast, to facilitate islanding detect.Further, in the disturbing signal mechanism in mid-term or later stage, by dynamic gain adjustment unit 304 produced gain signal can be adjusted to and there is less numerical value, compound disturbing signal generation unit 326 is made to produce q shaft current disturbing signal 328 compared with fractional value and reactive disturbance signal 332, to maintain system stability according to this gain signal 306.
Figure 11 to Figure 16 shows other several execution mode of the isolated island protection module 172 shown in Fig. 2, wherein, the isolated island disturbing signal 178 that this isolated island protection module 172 produces is applied in d axle control loop or real power control loop 185, and this disturbance compensation signal 184 is applied into elimination or alleviates owing to injecting isolated island disturbing signal 178 at d axle control loop 185 and negative effect caused by q axle control loop.
Figure 11 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2.In the illustrated embodiment, this isolated island protection module 172 comprises voltage change detection unit 352 and disturbance generation unit 356.This voltage change detection unit 352 is connected with voltage transformation module 166, to receive the d shaft voltage feedback signal 175 of being carried out coordinate transform generation by this voltage transformation module 166.This voltage change detection unit 352 is configured to judge whether the d shaft voltage feedback signal 175 of this reception changes, and such as, whether departs from normal magnitude of voltage.More specifically, the d shaft voltage feedback signal 175 of this reception compares with normal magnitude of voltage by this voltage change detection unit 352, and obtains voltage deviation signal 354.This voltage deviation signal 354 is provided to disturbance generation unit 356, for generation disturbing signal.In other embodiments, also whether can be changed by the frequency of checking network side converter 32 output, and produce disturbing signal according to frequency change, such as, the frequency departure signal 224 that the frequency change detecting unit 222 described by Fig. 3 and Fig. 6 to Figure 10 produces produces disturbing signal.In some other execution modes, the frequency departure signal 224 that the voltage deviation signal 354 that also can simultaneously provide in conjunction with voltage change detection unit 352 and frequency change detecting unit 222 provide is to produce disturbing signal.
Please continue to refer to Figure 11, in one embodiment, the disturbing signal that this disturbance generation unit 356 produces comprises d shaft current disturbing signal 362.This d shaft current disturbing signal 362 can act on a suitable gain by the voltage deviation signal 354 that voltage change detection unit 352 provided and obtain.Be appreciated that this d shaft current disturbing signal 362 is mainly used to carry out disturbance to d axle control loop 185.As shown in above-mentioned formula (1), a slight current disturbing amount Δ I is done to d shaft current command signal 196, the active power of net side converter 32 output can be caused to change.Further according to formula (6), active power change can force the voltage of net side converter 32 output to change.And this voltage variety Δ V can be used for generation current disturbance Δ I further, and the symbol of this current disturbing is consistent with the symbol of change in voltage.Therefore, by this positive feedback mechanism, the change of voltage can be accumulated in the same direction, and finally disturbed out outside normal voltage range values.In normal operation, when electrical network 34 keeps normal electrical to be connected with net side converter 32, because the voltage compare of electrical network 34 is stablized, its enough by the voltage clamp of net side converter 32 output within normal voltage range values, therefore disturbing signal can't to export voltage have an impact.And when electrical network 34 loses the electrical connection with net side converter 32, electrical network 34 is lost the control to output voltage, and therefore, the disturbance quantity applied for each time is under the effect of positive feedback, can continue accumulation, and output voltage is disturbed out outside normal voltage range the most at last.In this case; when judging that the output voltage of net side converter 32 is disturbed out outside normal voltage really; also namely photovoltaic energy conversion system 20 operates when island state; corresponding protection act can be started; such as by isolated with net side converter 32 for local load 19; cut off Power supply, or directly close net side converter 32.
In the execution mode shown in Figure 11, d shaft current disturbing signal 362 carries out amplitude restriction by the first clipping unit 364, and the d shaft current disturbing signal 362 after restriction is transmitted to summator 368, to revise or disturbance d shaft current command signal 196.In another execution mode, also can directly use the d shaft current disturbing signal 362 limited without amplitude to revise d shaft current command signal 196.Amended d shaft current command signal 372 can carry out amplitude restriction through the second clipping unit 374, and the d shaft current command signal 376 after restriction is transmitted to current regulator 208 and regulates.In the execution mode replaced, also directly can directly send this amended d shaft current command signal 372 to current regulator 208 and regulate, and produce d shaft voltage command signal 212 and q shaft voltage command signal 214.
Please consult Figure 11 further, in one embodiment, this isolated island protection module 172 also comprises disturbance compensation unit 248, and this disturbance compensation unit 248 is for producing disturbance compensation signal 382 according to d shaft current disturbing signal 362 or 366.This disturbance compensation signal 382 is used to compensate owing to acting on disturbing signal at d axle control loop 185, such as d shaft current disturbing signal 362 or 366 and the unexpected reactive power change that causes at q axle.
More specifically, in one embodiment, this disturbance compensation signal 382 produced by this disturbance compensation unit 248 comprises d shaft voltage compensating signal.After this d shaft voltage compensating signal 382 first can carry out amplitude restriction by the 3rd clipping unit 384, send the d shaft voltage compensating signal 386 after restriction to summator 388 again, then by this summator 388, this d shaft voltage compensating signal 386 is added with d shaft voltage command signal 212, to produce the d shaft voltage command signal 392 after compensation.After this voltage compensation, can eliminate or reduce the above-mentioned unexpected reactive power change caused at q axle mentioned.
Figure 12 shows that the detailed module diagram of a kind of execution mode of the isolated island protection module 172 at least comprising the elements such as the current regulator 208 shown in Figure 11 and dynamic compensation unit 248.Subelement shown in the subelement of Figure 12 and Fig. 4 is similar, therefore about these likes be described in this omit.In fig. 12, d shaft current disturbing signal 362 or 366 is imported into summator 223, to carry out disturbance to d shaft current command signal 196, and produces the d shaft current deviation signal 225 of disturbance.This d shaft current deviation signal 225, after d shaft current adjuster 227 regulates, obtains d shaft voltage command signal 227.Further, should comprise d axle compensated regulator 265 by disturbance compensation unit 248, this d axle compensated regulator 265 receives this d shaft current disturbing signal 362 or 366, and produces voltage compensation signal 271 accordingly.This voltage compensation signal 271 is transmitted to summator 229, then this voltage compensation signal 271 is added with this d shaft voltage command signal 227 by summator 229, with the d shaft voltage command signal 233 be compensated.By this compensation mechanism, the change of the reactive power caused owing to introducing active current disturbing signal can be eliminated or reduce, and when reactive power remains unchanged substantially, the voltage impelling net side converter 32 to export or frequency move outside normal voltage or frequency range values.Therefore; when electrical network 34 loses the electrical connection with net side converter 32; active current perturbation action can be passed through; frequency or voltage is made to disturb out outside normal value range; and after detecting that photovoltaic energy conversion system 20 is operated in island state; start corresponding protection act, guarantee the safety of system.In one embodiment; can the simultaneously voltage of checking network side converter 32 output or frequency; any one in voltage or frequency is detected at first is disturbed out outside the normal range (NR) of its correspondence; such as; output voltage is detected specific output frequency and first departs from its normal value range; namely think and isolated island situation detected, and start corresponding protection act.
The detailed module diagram of the another kind of execution mode of the isolated island protection module 172 for elements such as the current regulator 208 shown in Figure 11 and dynamic compensation unit 248 is at least comprised shown in Figure 13.In the illustrated embodiment, this dynamic compensation unit 248 is also configured to have dynamic overcompensation function, therefore also can be referred to as dynamic overcompensation unit.Especially, this dynamic overcompensation unit 248 comprises d axle overcompensation adjuster 267, and this d axle overcompensation adjuster 267 produces d axle overcompensation voltage signal 275 according to d shaft current disturbing signal 362 or 366.By this voltage overcompensation mechanism, not only can eliminate the unexpected idle change caused at q axle owing to injecting disturbing signal at d axle control loop 185, and mode that can be identical with d axle disturbing signal impels target electrical quantity, the change of such as voltage or frequency, to disturb out it more quickly outside normal voltage or frequency range.
Figure 14 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2.This isolated island protection module 172 shown in Figure 14 comprises voltage change ratio detecting unit 404 and dynamic gain adjustment unit 408.This voltage change ratio detecting unit 404 is connected with this voltage change detection unit 352, with receiver voltage deviation signal 354, and produces voltage change ratio signal 406 accordingly.This dynamic gain adjustment unit 408 is connected with this voltage change ratio detecting unit 404, to receive this voltage change ratio signal 406, and produces the gain signal 412 of following this voltage change ratio signal 406 dynamic change accordingly.For example, can be adjusted at the early stage of disturbance or this gain signal 412 of initial stage and there is relatively large numerical value, to make current disturbing generation unit 356 can produce relatively large disturbing signal, accelerate the disturbance to target electrical quantity; Along with carrying out further of disturbance, in stage middle and later periods, this gain signal 412 can be adjusted to has relatively little numerical value, to reduce the amplitude of the disturbing signal that current disturbing generation unit 356 produces, maintains system stability.
Figure 15 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2.In the execution mode shown in Figure 15, this isolated island protection module 172 comprises voltage disturbance generation unit 414, and its voltage change signal 354 being configured to detect according to voltage change detection unit 352 produces direct voltage disturbing signal 416.With described in conjunction with Figure 11 above to revise d shaft voltage command signal 196 similar, this direct voltage disturbing signal 416 is used to amendment direct voltage command signal 192, to change the active power of net side converter 32 output, and the voltage of output or frequency is impelled to change.Certainly, also can carry out amplitude limit by the first clipping unit 418 to this direct voltage disturbing signal 416, and modify or disturbance by the 422 pairs of direct voltage command signals 192 of the disturbing signal after amplitude limit.Further, in one embodiment, this direct voltage disturbing signal 416 or 422 is fed to dynamic compensation unit 248, and is used for producing d shaft voltage compensating signal 382 by this dynamic compensation unit 248.Especially, this d shaft voltage compensating signal 382 is done after amplitude restriction through the 3rd clipping unit 384, d shaft voltage compensating signal 386 after its restriction is transmitted to summator 388, the d shaft voltage command signal 212 that this d axle compensating signal 386 and current regulator 208 produce is combined by this summator 388, to obtain d shaft voltage command signal 392 that is that revise or that compensate.By compensating d shaft voltage command signal 392, can eliminate or reduce the unexpected reactive power change owing to injecting caused by direct voltage disturbing signal 416 or 422, thus making the disturbance of direct voltage disturbing signal 414 or 422 more effective.
Figure 16 shows that the detailed module diagram of the another kind of execution mode of the isolated island protection module 172 shown in Fig. 2.Similar with the execution mode above described by composition graphs 6,8,10,14, this isolated island protection module 172 also comprises dynamic gain Regulation mechanism.By this dynamic gain Regulation mechanism, dynamic gain signal 412 can be acted on to produce the adjustable direct voltage disturbing signal 416 of amplitude, isolated island situation can be detected rapidly to make this photovoltaic energy conversion system 20 and also can maintain system stability simultaneously.
Figure 17 shows that the module diagram of the another kind of execution mode of the photovoltaic energy conversion system 40 of the isolated island protection module 172 being configured with improvement.In the illustrated embodiment, the photovoltaic converter device 14 of this photovoltaic energy conversion system 40 is based on the framework of single stage type.More specifically, this photovoltaic converter device 14 comprises net side converter 148, and it is configured to directly convert the direct voltage at DC bus 146 place the alternating voltage with appropriate frequency and amplitude to, with feed-in electrical network 16.This photovoltaic energy conversion system 40 comprises photovoltaic converter control device 18 further, and this photovoltaic converter control device 18 is connected with this photovoltaic converter device 14, for transmitting control signal 182 to this photovoltaic converter device 14, runs to control it.This photovoltaic converter control device 18 is similar with the photovoltaic converter control device 18 shown in Fig. 2.Equally, the element that function is similar, such as current transformation unit 164, voltage transformation module 166, phase-locked loop apparatus 168, current regulator 208, voltage-Reactive-power control device 198, the detail of the elements such as coordinate transform and modulating unit 138 or module is not shown in this omission.
In the execution mode shown in Figure 17, similar with the execution mode above described by composition graphs 2 to Figure 16, this photovoltaic converter control device 18 is also configured to the ability that can perform islanding detect mechanism or algorithm, especially, this photovoltaic converter control device 18 can perform such as disturbance compensation mechanism or algorithm, or disturbance overcompensation mechanism or algorithm, and dynamic gain Regulation mechanism or algorithm.Also namely, injecting the process of isolated island disturbing signal, simultaneously by producing and acting on disturbance compensation signal, with the unexpected change eliminated or reduce caused by the isolated island disturbing signal owing to injecting or counter productive.In one embodiment, the photovoltaic energy conversion system 40 of this single stage type can also perform maximum power point tracking (MaximumPowerPointTracking, MPPT) mechanism or algorithm.So a kind of controlling mechanism or algorithm is referred at this so-called " maximum power point tracking mechanism or algorithm ", it can be performed by photovoltaic converter control device 18, even if when to guarantee the irradiation energy change received in photovoltaic energy source 12, also maximum photovoltaic power can be extracted from photovoltaic energy source 12.
Refer to Figure 17, this photovoltaic energy conversion system 40 comprises maximum power point tracking device 26, this maximum power point tracking device 26 receives respectively by the photovoltaic current signal 112 detected by current sensor 28 and voltage sensor 32 and photovoltaic voltage signal 114, wherein, this current sensor 28 and photovoltaic sensor 32 are placed between this photovoltaic energy source 12 and this DC bus 146.This maximum power point tracking device 26 is configured to photovoltaic current signal 112 according to this reception and photovoltaic voltage signal 114 further, perform maximum power point tracking algorithm, such as, disturbance observation method or conductance increment method, to search out the best operating point in this photovoltaic energy source 12.In one embodiment, this maximum power point tracking device 26 provides direct voltage reference signal 192 according to this photovoltaic current signal 112 and photovoltaic voltage signal 114.Because the voltage at DC bus 146 place is substantially identical with the output voltage in photovoltaic energy source 12, the voltage therefore by controlling DC bus 146 place can search out maximum power point.The representative of this direct voltage reference signal 192 is desirably in the direct voltage that this DC bus 146 place obtains, it is transmitted to direct current voltage regulator 194, and be used for basis by the direct voltage feedback signal 188 measured by direct current voltage sensor 186 by direct current voltage regulator 194, produce d shaft current command signal 196, this d shaft current command signal also regulates to sending current regulator 208 to further.
Please consult Figure 17 further, this isolated island protection module 172 also can receive the frequency signal 176 provided by phase-locked loop apparatus 168 and the d shaft voltage signals 175 provided by voltage transformation module 166, according to the input frequency change received and change in voltage, and producing isolated island disturbing signal 178 and disturbance compensation signal 184 according to the frequency change detected and/or change in voltage.In one embodiment, this isolated island disturbing signal is applied into amendment or disturbance direct voltage reference signal 192.In one embodiment, the direct voltage reference signal 192 that this maximum power point tracking device 26 provides can be revised by isolated island disturbing signal 178, to change input power and power output, thus the poised state broken between net side converter 148 output with load (scheming not shown), to make more effectively to detect islet operation situation.Similarly, this disturbance compensation signal 184 is applied into elimination or reduces the unexpected change because introducing isolated island disturbing signal 178 produces.
Figure 18 shows that the flow chart of a kind of execution mode of islet operation detection or guard method 4000; perform this islet operation to detect or guard method 4000 conveniently can detect the photovoltaic energy conversion system 20 and 40 shown in Fig. 2 and Figure 17 of coming in and going out and whether operates in isolated island situation, and corresponding protection act can be started after isolated island situation being detected.In the following detailed description, each step of the method flow chart 4000 is mainly described in conjunction with this energy conversion system 20, the method flow chart 4000 can be programmed for program command or computer software, and is kept on the storage medium that can be read by computer or processor.When this program command is performed by computer or processor, each step as shown in the flowchart can be realized.Be appreciated that the medium of computer-readable can comprise volatibility with non-volatile, in any method or technology realize moveable and non-moveable medium.More specifically, the medium of computer-readable includes but not limited to random access storage device, read-only memory, electrically erasable read-only memory, flash memories, or the memory of other technologies, compact disc read-only memory, digitlization disk storage, or other forms of optical memory, cassette, tape, magnetic disc, or other forms of magnetic storage, and the storage medium that can be used to the predetermined information that stored energy is accessed by instruction execution system of any other form.
In one embodiment, the method 4000 can perform from step 4002.In step 4002, obtain one or more electrical quantity of energy conversion system 20 output.For example, obtain net side converter 32 output frequency by phase-locked loop apparatus 168, obtained the d axle component of net side converter 32 output voltage by voltage transformation module 166.
In step 4004, whether at least one electrical quantity that the method 4000 continues to detect this acquisition changes.For example, frequency can be detected by frequency change detecting unit 222 and whether change, voltage can also be detected by voltage change detection unit 352 and whether change.
In step 4006, as an optional step.Isolated island disturbing signal is produced by performing dynamic gain Regulation mechanism.Step 4006 can comprise sub-step 4003 and 4005, with by determining that the rate of change of electrical quantity determines corresponding gain signal.For example, in sub-step 4003, detect voltage change ratio signal and frequency change rate signal further by detected voltage change signal or frequency variation signal.In sub-step 4005, according to this voltage change ratio signal and or frequency change rate signal generation gain signal.More specifically, when frequency or change in voltage slower time, gain signal can be adjusted to and there is larger numerical value, the amplitude of disturbing signal is strengthened, to accelerate the movement of target electrical quantity, and when frequency or change in voltage very fast time, can suitably the numerical value of gain signal be turned down, the amplitude of disturbing signal is reduced, to maintain system stability.
In step 4012, produce isolated island disturbing signal.In one embodiment, the change of electrical quantity that can be extremely detected by the yield value that effect is fixing, produces isolated island disturbing signal.Such as, this isolated island disturbing signal can comprise q shaft current disturbing signal, reactive disturbance signal or its combination.In another execution mode, also can be produced isolated island disturbing signal by the dynamic gain produced in step 4006, can adjust to make the amplitude of isolated island disturbing signal.
In step 4014, produce disturbance compensation signal, to eliminate or to reduce the unexpected change caused by isolated island disturbing signal.In one embodiment, this disturbance compensation signal can comprise q shaft voltage compensating signal, and it is applied into elimination or reduces owing to injecting q shaft current disturbing signal or reactive power disturbance signal etc. at q axle control loop 187 and change in the unexpected active power that d axle control loop produces.In another execution mode, this step 4014 also can produce disturbance overcompensation signal.This disturbance overcompensation signal not only can eliminate above-mentioned unexpected change, and such as active power change, and can contribute other disturbance quantity, with step 4012 generations disturbing signal with identical type of action, the movement of promotion target electrical quantity.
In step 4016, at least produce based on above-mentioned isolated island disturbing signal and disturbance compensation signal the control signal controlling converter device running.This control signal can comprise the switching signal of opening or closing the semiconductor switch device in converter device.
In step 4018, judge whether one or more electrical parameter values exceeds default normal range (NR).More specifically, in one embodiment, this determining step 4018 can judge whether the frequency of this net side converter 32 output exceeds normal frequency range, or this determining step 4018 also can judge whether the voltage of this net side converter 32 output exceeds normal voltage range, or this determining step 4018 also can judge whether this net side converter 32 output frequency and output voltage exceed normal frequency range and normal voltage range respectively simultaneously.If when the one in this one or more electrical quantity or many persons are judged out and exceed its normal value range, the method flow process 4000 turns to step 4022 to perform; And if one in this one or more electrical quantity or many persons are judged out when not exceeding its normal value range, the method flow process 4000 turns to step 4002 to perform, to proceed isolated island condition detection.
In step 4022, the affirmative determination of response done by determining step 4018, also namely photovoltaic energy conversion system 20 operates in island state, the protection act of starting-up response.In one embodiment, this protection act is open the switch be connected between photovoltaic energy conversion system 20 and local load 36, to cut off Power supply between the two.In another execution mode, also can directly the such as net side converter 32 of the converter device 24 in photovoltaic energy conversion system 20 be closed, to stop exporting energy.
Although describe the present invention in conjunction with specific execution mode, those skilled in the art will appreciate that and can make many amendments and modification to the present invention.Therefore, recognize, the intention of claims is to be encompassed in all such modifications in true spirit of the present invention and scope and modification.

Claims (26)

1. an energy conversion system, is characterized in that: this energy conversion system comprises converter device and inverter controller, the input power conversion that this converter device is configured for be provided energy source becomes to export energy, this inverter controller and this converter device are electrically connected, and this inverter controller is configured for real component and the idle component of regulation output energy, this inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this disturbance compensation signal is for compensating the unexpected variable quantity caused by this isolated island disturbing signal, this isolated island protection module be also configured to this isolated island disturbing signal and disturbance compensation signal function to become to regulate in this output energy in real component and idle component any one or all, the electrical parameter values of this measurement is shifted out outside normal range (NR) when there is isolated island situation.
2. energy conversion system as claimed in claim 1, is characterized in that: this isolated island protection module comprises frequency change detecting unit, disturbance generation unit and compensating unit; This frequency change detecting unit is configured for the frequency signal receiving the phase-locked loop apparatus in this energy conversion system and obtain, and produces frequency variation signal based on this frequency signal; This disturbance generation unit is configured to receive this frequency variation signal, and produces this isolated island disturbing signal based on this frequency variation signal, so that the frequency values of this output energy is shifted out normal frequency range; This compensating unit and this disturbance generation unit are electrically connected, and this compensating unit is configured for and produces this disturbance compensation signal.
3. energy conversion system as claimed in claim 2, is characterized in that: this isolated island disturbing signal comprises reactive current disturbing signal or reactive power disturbance signal.
4. energy conversion system as claimed in claim 2, is characterized in that: this isolated island disturbing signal comprises reactive current disturbing signal and reactive power disturbance signal.
5. energy conversion system as claimed in claim 2, is characterized in that: this disturbance compensation signal comprises q shaft voltage compensating signal.
6. energy conversion system as claimed in claim 2, is characterized in that: this compensating unit is also configured to produce disturbance overcompensation signal; When there is isolated island situation, this this isolated island disturbing signal of disturbance overcompensation signal combination makes the frequency of this converter device output accelerate to shift out normal frequency range.
7. energy conversion system as claimed in claim 2, it is characterized in that: this isolated island protection module comprises frequency change rate detecting unit and dynamic gain adjustment unit further, this frequency change rate detecting unit is configured to produce frequency change rate signal based on this frequency variation signal; This dynamic gain adjustment unit and this frequency change rate detecting unit are electrically connected, this dynamic gain adjustment unit is configured to produce corresponding dynamic gain signal based on this frequency change rate signal, this dynamic gain signal is applied this disturbance generation unit, for the amplitude of the isolated island disturbing signal that this disturbance generation unit of dynamic conditioning produces.
8. energy conversion system as claimed in claim 1, is characterized in that: this isolated island protection module comprises voltage change detection unit, disturbance generation unit and compensating unit; This voltage change detection unit is configured for the voltage signal receiving the voltage transformation module in this energy conversion system and obtain, and produces voltage change signal based on this voltage signal; This disturbance generation unit is configured to receive this voltage change signal, and produce this isolated island disturbing signal based on this voltage change signal, the magnitude of voltage of this output energy shifted out normal voltage range or to shift out outside normal frequency range by the frequency values of this output energy; This compensating unit and this disturbance generation unit are electrically connected, and this compensating unit is configured for and produces this disturbance compensation signal, for the unexpected variable quantity compensated caused by isolated island disturbing signal.
9. energy conversion system as claimed in claim 8, is characterized in that: this disturbance compensation signal comprises d shaft voltage compensating signal.
10. energy conversion system as claimed in claim 8, is characterized in that: this compensating unit is also configured to produce disturbance overcompensation signal; When there is isolated island situation, this this isolated island disturbing signal of disturbance overcompensation signal combination makes the voltage of this converter device output or frequency accelerate to move out normal voltage range or frequency range.
11. energy conversion systems as claimed in claim 9, it is characterized in that: this isolated island protection module comprises voltage change ratio detecting unit and dynamic gain adjustment unit further, this voltage change ratio detecting unit is configured for and produces voltage change ratio signal based on this voltage change signal; This dynamic gain adjustment unit and this voltage change ratio detecting unit are electrically connected, this dynamic gain adjustment unit is configured to produce corresponding dynamic gain signal based on this voltage change ratio signal, this dynamic gain signal is applied this disturbance generation unit, for the amplitude of the isolated island disturbing signal that this disturbance generation unit of dynamic conditioning produces.
12. 1 kinds of energy conversion systems, is characterized in that: this energy conversion system comprises converter device and inverter controller; The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, and this inverter controller is configured for real component and the idle component of regulation output energy; This inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this frequency variation signal measured by converter device output and frequency change rate signal, and at least produce isolated island disturbing signal according to the frequency variation signal of this measurement and frequency change rate signal and produce disturbance compensation signal based on this isolated island disturbing signal, this disturbance compensation signal is for compensating the unexpected variable quantity caused by this isolated island disturbing signal.
13. 1 kinds of energy conversion systems, is characterized in that: this energy conversion system comprises converter device and inverter controller; The input power conversion that this converter device is configured for be provided energy source becomes to export energy; This inverter controller and this converter device are electrically connected, and this inverter controller is configured for real component and the idle component of regulation output energy; This inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this voltage change signal measured by converter device output and voltage change ratio signal, and at least produce isolated island disturbing signal according to the voltage change signal of this measurement and voltage change ratio signal and produce disturbance compensation signal based on this isolated island disturbing signal, this disturbance compensation signal is for compensating the unexpected variable quantity caused by this isolated island disturbing signal.
14. 1 kinds of energy conversion systems, is characterized in that: this energy conversion system comprises converter device and inverter controller, the input power conversion that this converter device is configured for be provided energy source becomes to export energy, this inverter controller and this converter device are electrically connected, this inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component regulating this output energy, and this second control loop is configured to the idle component regulating this output energy, this inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this isolated island protection module is also configured to this isolated island disturbing signal to be applied to this second control loop, to do disturbance to the idle component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this second control loop, the voltage instruction that this second control loop produces is compensated, keep stable with the real component maintaining this first control loop when acting on this isolated island disturbing signal.
15. 1 kinds of energy conversion systems, is characterized in that: this energy conversion system comprises converter device and inverter controller, the input power conversion that this converter device is configured for be provided energy source becomes to export energy, this inverter controller and this converter device are electrically connected, this inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component regulating this output energy, and this second control loop is configured to the idle component regulating this output energy, this inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this isolated island protection module is also configured to this isolated island disturbing signal to be applied to this first control loop, to do disturbance to the real component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this first control loop, the voltage instruction that this first control loop produces is compensated, keep stable with the idle component maintaining this second control loop when acting on this isolated island disturbing signal.
16. 1 kinds of inverter controllers, it is configured for and controls converter device execution energy conversion operation, it is characterized in that: this inverter controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this disturbance compensation signal is for compensating the unexpected variable quantity caused by this isolated island disturbing signal, this isolated island protection module be also configured to this isolated island disturbing signal and disturbance compensation signal function to become to regulate in this output energy in real component and idle component any one or all, the electrical parameter values of this measurement is shifted out outside critical field when there is isolated island situation.
17. 1 kinds of inverter controllers, it is configured for and controls converter device execution energy conversion operation, it is characterized in that: this inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component of the output energy regulating this converter device to provide, and this second control loop is configured to the idle component of the output energy regulating this converter device to provide, this inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this isolated island protection module is also configured to this isolated island disturbing signal to be applied to this second control loop, to do disturbance to the idle component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this second control loop, the voltage instruction that this second control loop produces is compensated, keep stable with the real component maintaining this first control loop when acting on this isolated island disturbing signal.
18. 1 kinds of inverter controllers, it is configured for and controls converter device execution energy conversion operation, it is characterized in that: this inverter controller comprises the first control loop and the second control loop, this first control loop is configured for the real component of the output energy regulating this converter device to provide, and this second control loop is configured to the idle component of the output energy regulating this converter device to provide, this inverter controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this converter device, this isolated island protection module is configured to receive this electrical parameter values measured by converter device output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this isolated island protection module is also configured to this isolated island disturbing signal to be applied to this first control loop, to do disturbance to the real component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this first control loop, the voltage instruction that this first control loop produces is compensated, keep stable with the idle component maintaining this second control loop when acting on this isolated island disturbing signal.
19. 1 kinds, for carrying out the method for islanding detect to energy conversion system, is characterized in that: the method at least comprises the steps:
Receive this electrical quantity measured by energy conversion system output;
At least produce isolated island disturbing signal based on this electrical quantity and produce disturbance compensation signal based on this isolated island disturbing signal;
Act on this isolated island disturbing signal, to shift out outside normal range (NR) when there is isolated island situation by this electrical quantity; And
Act on this disturbance compensation signal, to compensate the unexpected variable quantity caused by isolated island disturbing signal.
20. methods as claimed in claim 19, is characterized in that: the method also comprises the steps:
At least produce disturbance overcompensation signal based on this electrical quantity;
Act on this disturbance overcompensation signal, with in conjunction with this isolated island disturbing signal, this electrical quantity is accelerated to shift out outside this normal range (NR).
21. methods as claimed in claim 19, it is characterized in that: this step at least producing isolated island disturbing signal and disturbance compensation signal based on this electrical quantity comprises: the frequency variation signal at least measured by this energy conversion system output, or voltage change signal, or the combination of frequency variation signal and voltage change signal produces this isolated island disturbing signal and disturbance compensation signal.
22. methods as claimed in claim 19, is characterized in that: the method also comprises the steps:
Electrical quantity rate of change signal is produced based on this electrical quantity;
Corresponding dynamic gain signal is produced based on this electrical quantity rate of change signal; And
Act on this dynamic gain signal to regulate the amplitude of this isolated island disturbing signal.
23. 1 kinds, for carrying out the method for island protect to energy conversion system, is characterized in that: the method at least comprises the steps:
Receive this electrical quantity measured by energy conversion system output;
At least produce isolated island disturbing signal based on this electrical quantity and produce disturbance compensation signal based on this isolated island disturbing signal;
Act on this isolated island disturbing signal, to shift out outside normal range (NR) when there is isolated island situation by this electrical quantity;
Act on this disturbance compensation signal, to compensate the unexpected variable quantity caused by isolated island disturbing signal; And
When the electrical quantity measured by this output be judged out exceed this normal range (NR) time, make this energy conversion system stop export energy.
24. 1 kinds of photovoltaic energy conversion system, is characterized in that: this photovoltaic energy conversion system comprises DC bus, photovoltaic converter and photovoltaic controller, this DC bus is configured for the direct current energy receiving photovoltaic energy source and provide, this photovoltaic converter is configured to convert the direct current energy at this DC bus place to AC energy, this photovoltaic controller comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this photovoltaic converter, this isolated island protection module is configured to receive this electrical parameter values measured by photovoltaic converter output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this disturbance compensation signal is for compensating the unexpected variable quantity caused by this isolated island disturbing signal, this isolated island protection module is also configured to this isolated island disturbing signal to become with disturbance compensation signal function and the electrical parameter values of this measurement is shifted out outside critical field when there is isolated island situation.
25. photovoltaic energy conversion system as claimed in claim 24, it is characterized in that: this photovoltaic energy conversion system also comprises maximum power point tracking device, this maximum power point tracking device is configured to produce direct voltage reference signal based on the photovoltaic voltage signal measured at this photovoltaic energy source place and photovoltaic current signal; Wherein, when there is isolated island situation, this isolated island disturbing signal revises this direct voltage reference signal.
26. 1 kinds of photovoltaic energy conversion system, is characterized in that: this photovoltaic energy conversion system comprises DC bus, photovoltaic converter and photovoltaic controller, this DC bus is configured for the direct current energy receiving photovoltaic energy source and provide, this photovoltaic converter is configured to convert the direct current energy at this DC bus place to AC energy, this photovoltaic controller comprises d axle control loop and q axle control loop, this d axle control loop is configured to regulate the real component in this photovoltaic converter output AC energy, and this q axle control loop is configured to regulate the idle component in this photovoltaic converter output AC energy, this photovoltaic controller also comprises isolated island protection module, this isolated island protection module is connected with the output electrical communication of this photovoltaic converter, this isolated island protection module is configured to receive this electrical parameter values measured by photovoltaic converter output, and at least produce isolated island disturbing signal according to the electrical parameter values of this measurement and produce disturbance compensation signal based on this isolated island disturbing signal, this isolated island protection module is also configured to this isolated island disturbing signal is applied to this d axle control loop, to do disturbance to the real component of this output energy, this isolated island protection module is also configured to this disturbance compensation signal function to this d axle control loop, the voltage instruction that this d axle control loop produces is compensated, keep stable with the idle component maintaining this q axle control loop when acting on this isolated island disturbing signal.
CN201210080623.5A 2012-03-23 2012-03-23 Inverter controller, energy conversion system, photovoltaic energy conversion system and method Active CN103326350B (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CN201210080623.5A CN103326350B (en) 2012-03-23 2012-03-23 Inverter controller, energy conversion system, photovoltaic energy conversion system and method
PCT/US2013/033062 WO2013142553A2 (en) 2012-03-23 2013-03-20 System and method for islanding detection and protection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201210080623.5A CN103326350B (en) 2012-03-23 2012-03-23 Inverter controller, energy conversion system, photovoltaic energy conversion system and method

Publications (2)

Publication Number Publication Date
CN103326350A CN103326350A (en) 2013-09-25
CN103326350B true CN103326350B (en) 2016-03-16

Family

ID=48050942

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201210080623.5A Active CN103326350B (en) 2012-03-23 2012-03-23 Inverter controller, energy conversion system, photovoltaic energy conversion system and method

Country Status (2)

Country Link
CN (1) CN103326350B (en)
WO (1) WO2013142553A2 (en)

Families Citing this family (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104600725B (en) * 2013-10-31 2017-09-29 西门子公司 photovoltaic series compensation system
CN103606907A (en) * 2013-11-15 2014-02-26 江苏兆伏新能源有限公司 An anti-islanding detection method
JP6159271B2 (en) * 2014-02-21 2017-07-05 株式会社日立製作所 Power converter and control method of power converter
CN104135206B (en) * 2014-07-15 2017-01-11 邯郸美的制冷设备有限公司 Motor control system and current regulator for same
WO2016149926A1 (en) * 2015-03-26 2016-09-29 国网河北省电力公司电力科学研究院 Anti-islanding method and device for distributed power source of direct-current electric distribution network
CN105048471B (en) * 2015-07-08 2017-12-12 国网山东省电力公司电力科学研究院 Wind electric converter net side SVG mode progress control methods in a kind of micro-grid system
ES2818048T3 (en) * 2015-08-31 2021-04-09 Otis Elevator Co Automatic commissioning of controller for active three-phase power electronic converters
US20180241211A1 (en) * 2015-09-02 2018-08-23 United Technologies Corporation Multifunctional power correction device
US10965153B2 (en) 2016-02-05 2021-03-30 Duke Energy Corporation Methods of microgrid communications and connection transitions
WO2018222650A1 (en) * 2017-05-31 2018-12-06 Schneider Electric Solar Inverters Usa, Inc. Systems and methods for islanding detection
DE102017114306B4 (en) * 2017-06-28 2019-01-17 Sma Solar Technology Ag METHOD FOR OPERATING AN ISLAND NETWORK AND ISLAND NETWORK
EP3692617A1 (en) 2017-10-06 2020-08-12 Vestas Wind Systems A/S Method for operating a wind power facility
JP6996444B2 (en) * 2018-07-20 2022-01-17 住友電気工業株式会社 Power converter and flicker detection method
CN114336723B (en) * 2020-09-29 2024-02-02 南京南瑞继保电气有限公司 Island fault ride-through control method and device for converter of flexible direct current transmission system
CN114362180B (en) * 2021-12-28 2023-04-14 国网江苏省电力有限公司电力科学研究院 LCL type grid-connected inverter compensation method, system, storage medium and computing equipment
CN117856267A (en) * 2024-03-07 2024-04-09 上海融和元储能源有限公司 Isolated network system control strategy and system for disturbance rejection optimization processing from data source

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102262182A (en) * 2011-07-07 2011-11-30 浙江大学 Method for detecting island of photovoltaic grid-connected inverter

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7016793B2 (en) * 2003-10-01 2006-03-21 General Electric Company Method and apparatus for anti-islanding protection of distributed generations
US7906870B2 (en) * 2006-10-13 2011-03-15 Pv Powered, Inc. System and method for anti-islanding, such as anti-islanding for a grid-connected photovoltaic inverter
CN101257209B (en) * 2008-01-10 2010-06-16 清华大学深圳研究生院 Islet operation detecting method of photovoltaic parallel network generating system
KR101120367B1 (en) * 2010-06-22 2012-03-02 성균관대학교산학협력단 Apparatus and method for anti-islanding of power conditioning system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102262182A (en) * 2011-07-07 2011-11-30 浙江大学 Method for detecting island of photovoltaic grid-connected inverter

Also Published As

Publication number Publication date
CN103326350A (en) 2013-09-25
WO2013142553A3 (en) 2014-02-27
WO2013142553A2 (en) 2013-09-26

Similar Documents

Publication Publication Date Title
CN103326350B (en) Inverter controller, energy conversion system, photovoltaic energy conversion system and method
Baghaee et al. A decentralized power management and sliding mode control strategy for hybrid AC/DC microgrids including renewable energy resources
Ahmad et al. An improved power control strategy for grid‐connected hybrid microgrid without park transformation and phase‐locked loop system
CN112086997B (en) Photovoltaic coordination frequency modulation control method based on variable power tracking and super capacitor storage
CN102904272A (en) Energy conversion system with improved transient event ride through and method
CN102904273A (en) Maximum power point tracking (MPPT) control of energy conversion system and relevant method
Zhong et al. DC-side synchronous active power control of two-stage photovoltaic generation for frequency support in Islanded microgrids
CN108599259B (en) Micro-grid active operation decision method based on sensitivity analysis
Samadi et al. Reactive power dynamic assessment of a PV system in a distribution grid
Behera et al. A novel resilient control of grid-integrated solar PV-hybrid energy storage microgrid for power smoothing and pulse power load accommodation
Chandak et al. Load shedding strategy coordinated with storage device and D-STATCOM to enhance the microgrid stability
Pouresmaeil et al. Double synchronous controller for integration of large-scale renewable energy sources into a low-inertia power grid
Mahdavian et al. Microgrid small‐signal stability analysis considering dynamic load model
Firdaus et al. Auxiliary signal‐assisted droop‐based secondary frequency control of inverter‐based PV microgrids for improvement in power sharing and system stability
Demirtas et al. Small-signal modeling and robust multi-loop PID and H∞ controllers synthesis for a self-excited induction generator
Mosa et al. Frequency support of AC microgrid with high penetration of photovoltaic using super-capacitor
Chandak et al. Robust power balancing scheme for the grid‐forming microgrid
Karaki et al. Frequency and voltage restoration for droop controlled AC microgrids
Qian et al. Analysis and implementation of virtual impedance for fixed‐frequency control strategy in microgrid
Zhang et al. Bus voltage stabilization control of photovoltaic DC microgrid based on fuzzy-PI dual-mode controller
CN103116074A (en) Alternate current network phase change detection and compensation system and method
Mohamed New control algorithms for the distributed generation interface in grid-connected and micro-grid systems
Zhu et al. Advanced control for grid-connected system with coordinated photovoltaic and energy storage
Chang et al. Parameter identification of controller for photovoltaic inverter based on LM method
CN104143832A (en) System and method for detecting and controlling voltage collapse condition

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant