CN102969730B - A kind of control method of double stage chain type energy storage converter - Google Patents
A kind of control method of double stage chain type energy storage converter Download PDFInfo
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- 238000004146 energy storage Methods 0.000 title claims abstract description 62
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Abstract
The invention provides a kind of control method of double stage chain type energy storage converter, the method carrys out by the voltage ripple controlling double-stage chain type current transformer intermediate dc electric capacity C the 100Hz fluctuating power that buffering accumulated energy system exchanges with electrical network, and maintenance electric capacity C voltage mean value is constant simultaneously; The two-way DC/DC current transformer of prime, by controlling the voltage of DC capacitor C, carrys out the secondary pulsation of level and smooth battery current, thus the charge-discharge electric power of level and smooth battery; And chain type energy accumulation current converter is used as the interface of energy-storage battery group and electrical network, realizes high pressure direct grid-connected, and complete power dispatching.Control method of the present invention is simple for described double stage chain type energy storage converter topological structure, and control objectives is clear and definite, obviously can improve the charge-discharge electric power of battery, increases the life-span of battery, improves the reliability of system for chain type energy storage.
Description
Technical field
The present invention relates to technical field of electric automation equipment, particularly, relate to a kind of control method of double stage chain type energy storage converter.
Background technology
Battery energy storage dynamic response is fast, can fluctuate by smooth power, strengthens system schedulability, improve electrical network static and dynamic performance.In addition, because energy-storage system can also operate in STATCOM pattern, reactive power support can be provided to electrical network where necessary.
Chain type topology, as energy accumulation current converter, directly can access high-voltage fence.Chain type energy accumulation current converter has multiple concrete topology as energy accumulation current converter: energy storage battery group directly accesses each H bridge DC side of chain type current transformer, its topology as shown in Figure 1, this topology makes energy storage battery need directly to bear each 100Hz fluctuating power exchanged with electrical network of chain type energy accumulation current converter, and namely the charging and discharging currents of battery is 100Hz pulsating current; As shown in Figure 2, thus negative effect is caused to the life-span of energy storage battery.And if want the fluctuating power that level and smooth battery bears, then need to increase DC bus capacitor C, and effect is unsatisfactory.
A kind of double stage chain type battery energy storage current transformer, as shown in Figure 3, namely its principal character adds a two-way DC/DC current transformer to its topology in the middle of energy-storage battery group and H bridge module.Under common control strategy, be steady state value by the voltage controlling DC bus capacitor C by adjustment duty ratio, the low pressure of battery is only converted to constant high pressure by its function, now the charging and discharging currents of battery side is still the pulsating current of 100Hz, then now double stage chain type battery energy storage current transformer can not improve the charge-discharge characteristic of battery.
Find through retrieval, the people such as Jin Yiding are in " Electric Power Automation Equipment " article " Large Copacity chain type battery energy storage system and charge and discharge balancing thereof control " literary composition that 31 volumes the 3rd phase delivered by the end of March in 2011, for realizing high busbar voltage, the net energy storage of jumbo city. in conjunction with chain type DC/AC converter topology and the two-way DC/DC Semiconductor Converting Technology of multiplex, propose one and be suitable for Large Copacity, the battery energy storage system structure of many energy-storage modules, this energy-storage system can not directly access 10kV above bus by step-up transformer, and good output harmonic wave characteristic can be issued to compared with low switching frequency, in system, the direct voltage of each series unit can improve further on the basis of battery pack terminal voltage, and allows many Battery packs parallel connection access, proposes three grades of battery charging and discharging balance policies for connection delta chained form system.By the object of this topology in this article, one is reduce the voltage of battery side, and one is can many Battery packs in parallel, thus improves overall capacity.Its control strategy is general control strategy recited above, can not improve the charge-discharge characteristic of battery.
Summary of the invention
For defect of the prior art, the object of this invention is to provide a kind of control method of double stage chain type energy storage converter, the method carrys out by the voltage ripple controlling double stage chain type energy storage converter intermediate dc electric capacity C the fluctuating power that buffering accumulated energy system and electrical network exchange, and reaches the object of buffer battery energy-storage system charge-discharge electric power.
For achieving the above object, the present invention is by the following technical solutions:
The invention provides a kind of control method of double stage chain type energy storage converter, described double stage chain type energy storage converter circuit topology comprises energy-storage battery group, two-way DC/DC current transformer, intermediate dc electric capacity C, chain type current transformer and networking filter reactor L
s.Wherein energy-storage battery group is through the intermediate dc electric capacity C of each H bridge of two-way DC/DC current transformer access chain type current transformer, and chain type current transformer is through networking filter reactor L
saccess high-voltage fence; Described control method of double stage chain type energy storage converter carrys out by the voltage ripple that described two-way DC/DC current transformer controls intermediate dc electric capacity C the fluctuating power that buffering accumulated energy system and electrical network exchange, do not affecting under the prerequisite that chain type current transformer normally works, DC capacitor C is allowed to fluctuate by given instruction in setting range, thus avoid the fluctuation of energy-storage battery power, maintain intermediate dc electric capacity C voltage mean value constant simultaneously.
Preferably, described DC/DC current transformer adopts double-loop control, adopts inductor current feedback inner ring to control and the control of middle dc voltage feedback outer shroud, controls intermediate capacitance average voltage constant when energy-storage system charging, electric discharge; Chain type current transformer adopts current decoupled control according to dispatching of power netwoks order, by dispatching command to absorbing, sending corresponding active power, reactive power.
Preferably, in described control method of double stage chain type energy storage converter, the voltage of intermediate dc electric capacity C is allowed to have 100Hz to fluctuate.
Preferably, the voltage of described intermediate dc electric capacity C is directly controlled by described two-way DC/DC current transformer, by controlling the voltage of described intermediate dc electric capacity C, described intermediate dc electric capacity C voltage is made to produce the fluctuation of 100Hz, thus the fluctuating power that the battery making described two-way DC/DC current transformer connect bears diminishes, the average voltage simultaneously maintaining described intermediate dc electric capacity C is constant.
Preferably, described DC/DC current transformer adopts double-loop control, adopts inductor current feedback inner ring to control and the control of middle dc voltage feedback outer shroud, controls described intermediate dc electric capacity C voltage mean value constant when energy-storage system charging, electric discharge; Chain type current transformer adopts current decoupled control according to dispatching of power netwoks order, by dispatching command to absorbing, sending corresponding active power, reactive power.
More preferably, prime DC/DC current transformer outer shroud Voltage Feedback in described double stage chain type energy storage converter adopts low pass filter to obtain the mean value of intermediate capacitance voltage, the inner ring given value of current that outer shroud voltage controller provides is 100Hz ripple, described DC/DC current transformer will control inductive current without 100Hz ripple, namely battery current is without 100Hz ripple, the power that now described chain type current transformer and electrical network exchange is that secondary is pulsed, namely the energy stored by described intermediate dc electric capacity C has 100Hz to fluctuate, and is reflected as the 100Hz fluctuation of described intermediate dc electric capacity C voltage.
More preferably, the prime DC/DC current transformer outer shroud Voltage Feedback of described double stage chain type energy storage converter adopts and directly feeds back, the cut-off frequency of design outer shroud voltage controller is less than 100Hz, namely the 100Hz voltage ripple misaligning a DC capacitor C voltage controls, the inner ring given value of current that outer shroud voltage controller provides is 100Hz ripple, then described DC/DC current transformer will control inductive current without 100Hz ripple, namely battery current is without 100Hz ripple, the power exchanged due to described chain type current transformer and electrical network is that secondary is pulsed, namely the energy stored by described intermediate dc electric capacity C has 100Hz to fluctuate, be reflected as the 100Hz fluctuation of the voltage of described intermediate dc electric capacity C.
Compared with prior art, the present invention has following beneficial effect:
A kind of control method of double stage chain type energy storage converter that the present invention proposes, can not affect under the prerequisite that chain type current transformer normally works, DC capacitor C is allowed to fluctuate by given instruction within the specific limits, thus avoid the fluctuation of energy-storage battery power, reach the object of buffer battery energy-storage system charge-discharge electric power.
Accompanying drawing explanation
By reading the detailed description done non-limiting example with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:
Fig. 1 is existing chain type energy accumulation current converter circuit topology;
The work wave of each H bridge inverter when Fig. 2 is stable state;
Fig. 3 is double stage chain type energy storage converter circuit topology;
Fig. 4 is the double-stage chain type current transformer being with two-way buck/boost;
Fig. 5 is the first control method block diagram;
Fig. 6 is the second control method block diagram;
The work wave of two-way buck/boost current transformer when Fig. 7 is stable state.
Embodiment
Below in conjunction with specific embodiment, the present invention is described in detail.Following examples will contribute to those skilled in the art and understand the present invention further, but not limit the present invention in any form.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, some distortion and improvement can also be made.These all belong to protection scope of the present invention.
With reference to Fig. 3, a kind of double stage chain type energy storage converter circuit topology, this circuit topology comprises energy-storage battery group, two-way DC/DC current transformer, intermediate dc electric capacity C, chain type current transformer and networking filter reactor L
s.Wherein: described energy-storage battery group accesses the described intermediate dc electric capacity C of described chain type current transformer each H bridge through described two-way DC/DC current transformer, and described chain type current transformer is through described networking filter reactor L
saccess high-voltage fence (3.3kV, 6.6kV, 10kV).
Described two-way DC/DC current transformer adopts double-loop control, adopts inductor current feedback inner ring to control and the control of middle dc voltage feedback outer shroud, controls intermediate capacitance average voltage constant when energy-storage system charging, electric discharge; Chain type current transformer adopts current decoupled control according to dispatching of power netwoks order, by dispatching command to absorbing, sending corresponding active power, reactive power.
Described control method of double stage chain type energy storage converter cushions by the voltage ripple controlling intermediate dc electric capacity C the 100Hz fluctuating power that chain type current transformer and electrical network exchange, avoid the fluctuation of energy-storage battery power, maintain intermediate dc electric capacity C voltage mean value constant simultaneously.
The specific implementation of described control method of double stage chain type energy storage converter has two kinds of methods, as Fig. 4 is described for the control of stage type chain type current transformer of two-way buck/boost circuit and chain type current transformer composition.
The first control method as shown in Figure 5: the prime DC/DC current transformer outer shroud Voltage Feedback u in double stage chain type energy storage converter
cthe mean value of intermediate capacitance voltage is obtained through low pass filter
direct voltage reference value with
difference through outer shroud voltage controller, the inner ring current reference value provided.After this current reference value and battery current i
batthe empty ratio of point is produced again through electric current loop.Because current reference value is without 100Hz ripple, therefore will to control inductive current constant for DC/DC current transformer, and namely battery current is without 100Hz ripple.The power now exchanged due to chain type current transformer and electrical network is that secondary is pulsed, and the energy namely stored by intermediate dc electric capacity has 100Hz to fluctuate, and is reflected as the 100Hz fluctuation of intermediate capacitance voltage.
The second control method as shown in Figure 6: the prime DC/DC current transformer outer shroud Voltage Feedback of double stage chain type energy storage converter adopts directly feedback, direct voltage reference value and u
cdifference through outer shroud voltage controller, the inner ring current reference value provided.The cut-off frequency now designing outer shroud voltage controller is less than 100Hz, and the 100Hz voltage ripple namely misaligning a capacitance voltage controls, and the inner ring current reference that outer shroud voltage controller provides is without 100Hz ripple.After this current reference value and battery current i
batthe empty ratio of point is produced again through electric current loop.Because current reference value is without 100Hz ripple, therefore DC/DC current transformer will control inductive current without 100Hz ripple, and namely battery current is without 100Hz ripple.The power now exchanged due to chain type current transformer and electrical network is that secondary is pulsed, and the energy namely stored by intermediate dc electric capacity C has 100Hz to fluctuate, and is reflected as the 100Hz fluctuation of intermediate capacitance voltage.
With reference to Fig. 7, during battery discharge, the work wave of two-way DC/DC current transformer, flows through the current i of battery
batfor steady state value, two-way DC/DC current transformer output capacitance voltage v
2there is the voltage ripple of 100Hz, flow to the low frequency component i of power network current from the intermediate dc electric capacity C of H bridge
dcfor the form of the Sine-squared of 100Hz.
Compared with the general control strategy of topology shown in the control strategy of the present invention and traditional chain type current transformer and Fig. 3, can not affect under the prerequisite that chain type current transformer normally works, allow DC capacitor C to fluctuate by given instruction within the specific limits, thus reach the object of buffer battery energy-storage system charge-discharge electric power.As above-described embodiment allows the voltage of intermediate dc lateral capacitance to have 100Hz to fluctuate, thus avoid the fluctuation of energy-storage battery power.Chain type energy accumulation current converter is used as the interface of energy-storage battery group and electrical network, realizes high pressure direct grid-connected, and completes power dispatching.
Control method of double stage chain type energy storage converter of the present invention is for described double stage chain type energy storage converter topology, structure is simple, and control objectives is clear and definite, obviously can improve the charge-discharge electric power of battery, increase the life-span of battery, improve the reliability of system for chain type energy storage.
Above specific embodiments of the invention are described.It is to be appreciated that the present invention is not limited to above-mentioned particular implementation, those skilled in the art can make various distortion or amendment within the scope of the claims, and this does not affect flesh and blood of the present invention.
Claims (2)
1. a control method of double stage chain type energy storage converter, described double stage chain type energy storage converter circuit topology comprises: energy-storage battery group, two-way DC/DC current transformer, intermediate dc electric capacity (C), chain type current transformer and networking filter reactor (L
s), wherein said energy-storage battery group is through the described intermediate dc electric capacity (C) of described two-way DC/DC current transformer access chain type current transformer each H bridge, and described chain type current transformer is through described networking filter reactor (L
s) access high-voltage fence; It is characterized in that, the voltage ripple controlling intermediate dc electric capacity (C) by described two-way DC/DC current transformer carrys out the fluctuating power that buffering accumulated energy system and electrical network exchange, do not affecting under the prerequisite that chain type current transformer normally works, DC capacitor (C) is allowed to fluctuate by given instruction in setting range, thus avoid the fluctuation of energy-storage battery power, maintain intermediate dc electric capacity (C) average voltage constant simultaneously;
Described DC/DC current transformer adopts double-loop control, adopts inductor current feedback inner ring to control or the control of middle dc voltage feedback outer shroud, controls described intermediate dc electric capacity (C) average voltage constant when energy-storage system charging, electric discharge; Chain type current transformer adopts current decoupled control according to dispatching of power netwoks order, by dispatching command to absorbing, sending corresponding active power, reactive power;
Prime DC/DC current transformer outer shroud Voltage Feedback in described double stage chain type energy storage converter adopts low pass filter to obtain the mean value of intermediate capacitance voltage, the inner ring given value of current that outer shroud voltage controller provides is 100Hz ripple, described DC/DC current transformer will control inductive current without 100Hz ripple, namely battery current is without 100Hz ripple, the power that now described chain type current transformer and electrical network exchange is that secondary is pulsed, namely the energy stored by described intermediate dc electric capacity (C) has 100Hz to fluctuate, and is reflected as the 100Hz fluctuation of described intermediate dc electric capacity (C) voltage;
The prime DC/DC current transformer outer shroud Voltage Feedback of described double stage chain type energy storage converter adopts and directly feeds back, the cut-off frequency of design outer shroud voltage controller is less than 100Hz, namely the 100Hz voltage ripple misaligning a DC capacitor (C) voltage controls, the inner ring given value of current that outer shroud voltage controller provides is 100Hz ripple, then described DC/DC current transformer will control inductive current without 100Hz ripple, namely battery current is without 100Hz ripple, the power exchanged due to described chain type current transformer and electrical network is that secondary is pulsed, namely the energy stored by described intermediate dc electric capacity (C) has 100Hz to fluctuate, be reflected as the 100Hz fluctuation of the voltage of described intermediate dc electric capacity (C).
2. control method of double stage chain type energy storage converter according to claim 1, it is characterized in that, the voltage of described intermediate dc electric capacity (C) is directly controlled by described two-way DC/DC current transformer, by controlling the voltage of described intermediate dc electric capacity (C), described intermediate dc electric capacity (C) voltage is made to produce the fluctuation of 100Hz, thus the fluctuating power that the battery making described two-way DC/DC current transformer connect bears diminishes, the average voltage simultaneously maintaining described intermediate dc electric capacity (C) is constant.
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| CN103280829B (en) * | 2013-04-26 | 2016-06-01 | 上海交通大学 | A kind of isolation double-stage chain type current transformer being applied to high capacity cell energy storage |
| CN103457271A (en) * | 2013-08-02 | 2013-12-18 | 上海交通大学 | Chained static synchronous compensator with active power adjusting capacity and cascading unit thereof |
| CN106877726B (en) * | 2017-03-30 | 2019-05-03 | 上海交通大学 | A kind of control method of the accumulation energy type converter topology with fault ride-through capacity |
| CN106877713B (en) * | 2017-03-30 | 2019-05-17 | 上海交通大学 | A kind of accumulation energy type converter topology with fault ride-through capacity |
| CN107017798B (en) * | 2017-03-30 | 2019-06-07 | 上海交通大学 | A kind of modular multi-level converter topology with energy-storage function |
| CN106936149B (en) * | 2017-04-19 | 2024-02-02 | 上海蔚来汽车有限公司 | Chain type energy storage equipment and energy storage power station |
| CN109327130B (en) * | 2018-10-26 | 2020-04-03 | 南方电网科学研究院有限责任公司 | Single-stage chained energy storage converter control method, device, equipment and storage medium |
| CN109728369B (en) * | 2018-12-21 | 2020-09-04 | 上海交通大学 | Self-adaptive control method and system of chain type energy storage system based on power battery |
| CN110350564B (en) * | 2019-07-30 | 2020-04-21 | 清华大学 | High-voltage direct-hanging energy storage device and power control method |
| CN113567748B (en) * | 2020-04-28 | 2022-05-31 | 株洲中车时代电气股份有限公司 | Converter direct current capacitance detection method, life prediction method and system |
| CN113489025B (en) * | 2021-07-15 | 2023-03-07 | 西安热工研究院有限公司 | Control method for assisting AGC frequency modulation super-capacitor device of thermal power generating unit |
| CN114123424B (en) * | 2021-12-03 | 2023-09-05 | 香港理工大学深圳研究院 | Reliable and rapid battery depolarized charge and discharge control operation method |
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Application publication date: 20130313 Assignee: Shanghai Zhonglv New Energy Technology Co.,Ltd. Assignor: SHANGHAI JIAO TONG University Contract record no.: X2024980003752 Denomination of invention: A control method for a two-stage chain energy storage inverter Granted publication date: 20151209 License type: Common License Record date: 20240401 |