CN102611131B - For operating the method and system of electricity generation system - Google Patents

Abstract

The present invention relates to the method and system for operating electricity generation system.Describe a kind of photovoltaic (PV) electricity generation system (100).This system includes multiple PV collector unit (102), and it includes at least one PV battery (124) and collector side single-phase inverter (122).These multiple PV collector unit are disposed for exchanging (AC) load (18) coupling with symmetrical multi-phase.This system also includes the system controller (108) being configured to control the operation of these multiple PV collector unit.

Description

For operating the method and system of electricity generation system

Technical field

Embodiment described herein and relate generally to photovoltaic (PV) electricity generation system, and more particularly, to for by multiple Variable input single-phase direct current (DC) power supply is coupled to the system of symmetrical three-phase alternating current (AC) electrical network.

Background technology

Solar energy has gradually become the noticeable energy and has had been considered as cleaning, the alternative shape of the reproducible energy Formula.The solar energy using sunlight form can be converted to electric energy by solaode.For converting light to the dress of electric energy The more generic term put is " photovoltaic (PV) battery ".Sunlight is the subset of light.Thus, solaode is photovoltaic (PV) battery Subset.PV battery includes that pair of electrodes and the light being disposed there between absorb PV material.When with photoirradiation PV material, PV material In be restricted to the electronics of atom and discharged to move freely through by luminous energy.So, free electron and hole are just created.These are certainly It is sufficiently separated so that extracting electric energy constantly by electronics and hole.The PV battery of Current commercial uses quasiconductor PV material Material, typically silicon.

In order to obtain higher electric current and voltage, electrical connection solaode is to form solar energy module.Except multiple sun Outside energy battery, solar energy module may also include sensor, such as irradiation sensor, temperature sensor, and/or power meter.Also may be used Connect solar energy module to form module string.Typically, the D/C voltage of module string output is supplied to grid inverters, and such as DC is extremely AC voltage inverter.D/C voltage is converted to single-phase or three-phase alternating current (AC) voltage or electric current by this DC to AC voltage inverter.Three The output of phase AC can be supplied to power transformer, and it makes voltage rise to produce the three-phase high-voltage AC being applied to power distribution network.

The electricity being applied to power distribution network needs to meet the expection of electrical network connectedness.These requirements solve safety problem and electric power matter Amount is paid close attention to.Such as, the expection of electrical network connectedness is easy in the case of being included in transient affair (such as power surges or power failure) Electricity generation system is made to disconnect from electrical network.The expection of another electrical network connectedness is that the electric power produced is adjusted to guarantee electric power and flow through electricity The voltage of the electricity of net and frequency coupling.Such as, Institute of Electrical and Electric Engineers (IEEE) have been written that solution includes can be again The standard (IEEE1547-2003) of the distributed power generation that the electrical network of raw energy system connects.Underwriters Laboratory (UL) is the most Develop UL 1741 standard to prove to produce the inverter of the rechargeable energy system connected with electrical network for independent power, turn Parallel operation, electric charge control device and o controller.UL 1741 confirms that the IEEE connecting application for electrical network observed by inverter 1547。

Specifically, electrical network connect PV electricity generation system must be fulfilled for public interconnection demand, it include low-voltage crossing (LVRT), Voltage Cortrol and PFC.

Summary of the invention

In one aspect, it is provided that photovoltaic (PV) electricity generation system.This system includes multiple PV collector unit, it include to A few PV battery and collector side single-phase inverter.These multiple PV collector unit are configured to exchange (AC) with symmetrical multi-phase Load coupling.This system also includes the system controller being configured to control the operation of these multiple PV collector unit.

In yet another aspect, it is provided that for direct current (DC) electric power being converted to the exchange (AC) for being transported to electric loading The method of electric power.This DC electric power is produced by multiple variable input powers.The method includes providing multiple photovoltaic (PV) catcher Unit, each of which includes at least one PV battery and collector side single-phase inverter.These multiple PV collector unit are configured to Produce D/C voltage and this D/C voltage is converted into single-phase AC output.The method farther includes at least one system controller It is communicably coupled to these multiple PV collector unit, and system controller is programmed to control these multiple PV catcher lists The operation of unit.

In still another aspect, it is provided that electric power coversion system.This system includes multiple collector side single-phase inverter, its It is configured to receive variable input direct-current (DC) voltage.This system also includes system controller, and it is coupled to multiple collector side Single-phase inverter and be configured to control the operation of multiple collector side single-phase inverter.Multiple collector side single-phase inverters are joined It is set to provide symmetrical multi-phase exchange (AC) to electric loading.

Accompanying drawing explanation

Fig. 1 is the block diagram of known photovoltaic (PV) electricity generation system.

Fig. 2 is the block diagram of the first one exemplary embodiment of the PV electricity generation system including multiple collector side inverter.

Fig. 3 is the block diagram of the second one exemplary embodiment of PV electricity generation system shown in figure 2.

Fig. 4 is the block diagram of the one exemplary embodiment that may be included in the system controller in the PV electricity generation system shown in Fig. 2.

Fig. 5 is the block diagram of the first alternative of the PV electricity generation system including multiple collector side inverter.

Fig. 6 is the block diagram of the second alternative of the PV electricity generation system including multiple collector side inverter.

Fig. 7 is for controlling the flow chart of the exemplary method of the operation of PV electricity generation system illustrated in figs. 2-6.

Detailed description of the invention

Method described herein and system are easy to control multiple variable input single-phase power supply and are applicable in symmetry to produce The electric power distributed on three phase network and/or transmit.Method described herein and system realize electrical network connectedness expection, it include but Be not limited to, it is provided that stable state and transient state symmetry, the reactive power that controls, in response to symmetrical or asymmetrical fault current, finishing Ramp rate (ramp rate) and provide low-voltage crossing (LVRT) ability, minimize simultaneously Capital expenditure, electric power transition loss with And line loss.Method described herein and system are also convenient at the temporary fault of a part of generation assets or permanent regression Period supports the symmetry of electrical network.

The technique effect of method described herein and system includes following at least one: (a) provides multiple photovoltaic (PV) Collector unit, each of which includes at least one PV battery and collector side single-phase inverter, wherein these multiple PV catchers Cell location becomes to produce D/C voltage and this D/C voltage is converted into single-phase AC output；B at least one system controller is led to by () It is coupled to multiple PV collector unit letter；And, the programming of this at least one system controller is collected by (c) to control multiple PV The operation of device unit.

Fig. 1 is the block diagram of known photovoltaic (PV) electricity generation system 10.System 10 include PV collection device 12, inverter 14, Transformator 16 and electrical network 18.As mentioned in this article, electrical network 18 is to be configured to electricity distribution and/or the conductor of transmission and device Network.Typically, PV collection device 12 includes the multiple PV modules such as coupled by DC switchgear (the most not shown) String, this DC switchgear collects the D/C voltage from PV module string and output dc voltage 30.D/C voltage 30 is supplied to inverter 14.Inverter 14 regulates D/C voltage 30.Such as, inverter 14 can be DC/AC voltage inverter, and it is configured to D/C voltage 30 Be converted to three-phase low-voltage AC 32.

Three-phase low-voltage AC 32 is supplied to power transformer 16.Transformator 16 produces three-phase high-voltage AC 34, and it is applied to Load, such as, electrical network 18.System 10 also includes system controller 36.System controller 36 is coupled to inverter 14 and configures Become to control the operation of inverter 14.

Fig. 2 is the block diagram of the first one exemplary embodiment of the PV electricity generation system 100 including multiple PV collector unit 102. In this first one exemplary embodiment, multiple PV collector unit 102 use triangular arrangement to couple.Fig. 3 is to include multiple PV The block diagram of the second one exemplary embodiment of the PV electricity generation system 100 of collector unit 102.In this second one exemplary embodiment, Multiple PV collector unit 102 use star like arrangement (configuration of also referred to as Y word) to couple.

In the first one exemplary embodiment and the second one exemplary embodiment, PV electricity generation system 100 also includes grid side Inverter 104, power transformer 106 and system controller 108.Symmetry three-phase AC is supplied to electrical network by PV electricity generation system 100 18 (figure 1 illustrates).Although described herein as provide AC to electrical network 18, but system 100 AC can be supplied to any properly Load.In an exemplary embodiment, each of multiple PV collector unit 102 includes PV collection device and collector side inversion Device.Such as, a PV collector unit 120 includes the first collector side inverter being coupled to a PV collection device 124 122.2nd PV collector unit 126 includes the second collector side inverter 128 being coupled to the 2nd PV collection device 130.The Three PV collector unit 132 include the 3rd collector side inverter 134 being coupled to the 3rd PV collection device 136.4th PV receives Collector Units 138 includes the 4th collector side inverter 140 being coupled to the 4th PV collection device 142.5th PV catcher list Unit 144 includes the 5th collector side inverter 146 being coupled to the 5th PV collection device 148.6th PV collector unit 150 is wrapped Include the 6th collector side inverter 152 being coupled to the 6th PV collection device 154.Although illustratively including six PV catcher lists Unit, but system 100 can include any appropriate number of catcher list that permission system 100 works as described herein like that Unit.PV collection device 124,130,136,142,148 and 154 can include single PV battery, be assembled into multiple PV electricity of PV module Pond, assemble to form multiple PV modules of PV module string, or permission system 100 work like that as described herein any its He configures by PV battery.

Due to each PV collection device and collector side inverter of including of multiple PV collector unit 102, multiple PV receive The each of Collector Units 102 can about operate with power factor (unity power factor).Grasp close to unity power factor Make to be easy to maximum actual power be flowed to electrical network 18 with minimizing line loss.Additionally, multiple PV collector unit 102 is every Individual also being able at the maximum power point for inverter/collector combination operates.More specifically, each collector side inverter Can be separately controlled to mate the impedance of corresponding PV collection device, and therefore, operate at maximum power point.Such as, One collector side inverter 122 is controlled by system controller 108 with at the maximum power point for a PV collection device 124 Operation.Because each of multiple inverters can operate at different maximum power points, from PV collection device 124,130, 136,142,148 and 154 unique peak power is extracted.

In the first exemplary embodiment, as shown in Figure 2, multiple PV collector unit 102 low pressure exported Single-phase AC 158 is applied in three conductors (first conductor the 160, second conductor 162 or the 3rd conductor 164) of three-phase system Between two.Single-phase inverter 122,128,134,140,146 and 152 is alternatively coupled to three phase network 18 so that each inversion Device is connected between three conductors 160,162 and any two of 164.Conductor 160,162 and 164 is coupled to power transformer 106 and grid side inverter 104.

In the second one exemplary embodiment, as figure 3 illustrates, multiple PV collector unit 102 low pressure exported Single-phase AC 158 is applied in three conductors (first conductor the 160, second conductor 162 or the 3rd conductor 164) of three-phase system At least one.Single-phase inverter 122,128,134,140,146 and 152 is alternatively coupled to three phase network so that inverter every An individual output is connected in three conductors and each residue output of inverter is connected to neutral conductor 166. Conductor 160,162,164 and 166 is coupled to power transformer 106 by grid side inverter 104.

Power transformer 106 can be standard three-phase transformer, and it produces high pressure three-phase AC 174 and is used for being applied to electrical network 18 (figure 1 illustrates).In an exemplary embodiment, grid side inverter 104 make to be transported to the voltage stabilization of electrical network 18 and Adjust this voltage.During the steady state operation of system 100, symmetrical three-phase AC is provided by grid side inverter 104.In transient state thing During part, such as, along during the grid event such as the power surges of electrical network or LVRT event, grid side inverter 104 such as passes through Detect and compensate voltage disturbance (by the reactive power led or lag being injected on electrical network 18) and be easy to LVRT and zero electricity Pressure passes through (ZVRT).Additionally, grid side inverter 104 also can provide PFC during steady state operation.

In an exemplary embodiment, system controller 108 provides control signal 176 to perform to grid side inverter 104 Functions described herein.Additionally, when grid event being detected, system controller 108 provide power factor reference signal and/or It is one or more that power reduction signal is given in multiple collector unit 102, and more specifically, gives collector side inverter 122, at least one in 128,134,140,146 and 152.This system controller 108 can provide additional information, and (it includes reality And reactive power command) give those inverters being connected to common conductor 160,162 or 164.System 100 make inverter 122, 128, coordination necessary between 134,140,146 and 152 minimizes, thus is conducive to processing the life about system controller 108 Order, and it is easy to the higher electric power of each generation from multiple PV collector unit 102.System 100 is easy at each maximum work Operate each of multiple collector unit 102 at rate point, eliminate between collector unit 102 and grid side inverter 104 DC wiring, and during grid event provide collector unit 102 Fast Reduction.

Even if additionally, during the temporary derangement of subset and/or permanent regression of multiple PV collector unit 102, receiving Storage side inverter 122,128,134,140,146 and 152 permission system 100 provides symmetrical 3-phase AC power.Such as, even if receiving One or more in storage side inverter 122,128,134,140,146 and 152 had been lost efficacy, and system 100 provides symmetrical three Phase AC electric power.If the loss of the one or more generation in collector side inverter 122,128,134,140,146 and 152 Cause in electricity generation system 100 less desirable asymmetric, then control DC/AC transducer 104 and make reality and reactive power from tool The conductor having too much generating is extracted and provided to lack the conductor of generating.In certain embodiments, it is also possible to control system 100 makes Controlled asymmetric electricity generation system must be presented to electrical network 18 asymmetric to compensate the such as electrical network such as single-phase fault or asymmetrically placed load Property.It is to say, system 100 is easy to each reality and the reactive power controlling to be applied to conductor 160,162 and 164 respectively.

In certain embodiments, collector side inverter 122,128,134,140,146 and 152 are each includes memorizer list Unit 178.Such as, memory cell 178 is placed in collector side inverter 122, or is coupled to collector side inverter 122.Memory cell 178 stores the operating parameter of the operation for controlling collector side inverter 122.More specifically, make inverse Change device 122 can pass through the operating parameter of grid event and be storable in memory cell 178.Grid event can be by system control Device 108 identifies and/or is identified by inverter 122.Such as, memory cell 178 can store threshold value line voltage power command, electricity Pressure passes through return command and/or reactive power command.In certain embodiments, when line voltage is less than the threshold value electrical network electricity of storage During pressure, inverter 122 operates based on threshold value line voltage power command.The threshold value line voltage of storage may indicate that low-voltage crossing thing Part or no-voltage pass through the generation of event.Voltage ride-through return command can include predetermined amount of time, after which, inverter 122 It is instructed to start to provide electric power to electrical network 18.Voltage ride-through return command may also include predetermined ramp rate, thereby indicates that inverter 122 provide electric power to electrical network 18.Reactive power command can control the reactive power output of inverter 122 and (include when inverter 122 When will provide reactive power).Inverter 122 is easy in operation in response to the operating parameter being stored in memory cell 178 Autonomous Control (such as, based on be not from system controller 108 receive operating parameter control inverter 122).Additionally, storage Device unit 178 can include computer-readable medium, such as but not limited to, random access memory (RAM), flash memory, firmly Disk drive, solid-state drive, floppy disk, flash drive, CD, digital video dish, and/or can store, retrieve and/or Perform instruction and/or any applicable memorizer of data.Additionally, system controller 108 can be before grid event occurs The operating parameter that regulation is stored.

Additionally, in certain embodiments, multiple PV collector unit 102 are disperseed geographically.System controller 108 is controlled Collector unit 120 processed is with the different reactive power level provided from provided by collector unit 150.Multiple it is geographically spread out PV collector unit 102 each discriminably control so that the balancing run of PV electricity generation system 100 and be easy to make be System system loss minimization within 100.

Fig. 4 is the block diagram of the one exemplary embodiment of system controller 108 (figure 1 illustrates).In certain embodiments, it is System controller 108 includes bus 180 or other communicators of the information of transmission.One or more processors 182 are coupled to bus 180 to process information, and it includes the information from the sensor being included in PV collector unit 102.Processor 182 can include At least one computer.As it is used herein, term computer is not limited to be referred to as in the art the integrated circuit of computer, But broadly refer to processor, microcontroller, microcomputer, programmable logic controller (PLC) (PLC), special IC With other programmable circuits, and these terms the most alternatively use.

System controller 108 may also include one or more random access memory (RAM) 184 and/or other storage dresses Put 186.RAM 184 and storage device 186 be coupled to information that bus 180 to perform by processor 182 with storage and transmission and Instruction.RAM 184 (and/or storing device 186, if included) can also be used to be stored in and referred to by processor 182 execution Temporary variable during order or other average informations.System controller 108 may also include one or more read only memory (ROM) 188 and/or be coupled to other static memories of bus 180 with static (such as, the immovable) information of storage and instruction will It is supplied to processor 182.Processor 182 processes from multiple electricity and the electricity that may include but be not limited to irradiation sensor and power meter The information that sub-device transmits.The instruction being performed includes but not limited to, resident conversion and/or comparator algorithm.The execution of instruction Order is not limited to any particular combination of hardware circuit and software instruction.

System controller 108 may also include input/output device 190 or can be coupled to input/output device 190.Input/ Output device 190 can include known in the art providing input data to system controller 108 and/or provide output (such as, But be not limited to, solar panel location output and/or inverter control output) any device.Instruction can be by remotely connecting Connect (its be to provide access one or more can the wired or wireless connection of medium of electronic access) from including such as disk, read-only Memorizer (ROM) integrated circuit, the storage device 186 of CD-ROM and/or DVD are supplied to RAM 184.In certain embodiments, Hard-wired circuitry can substitute software instruction and uses or be used in combination with software instruction.Thus, regardless of whether be described herein as And/or illustrate, the execution sequence of instruction is not limited to any particular combination of hardware circuit and software instruction.And, exemplary In embodiment, input/output device 190 can include, but not limited to associate with operator interface (e.g., man machine interface (HMI)) Computer peripheral, such as mouse and keyboard (the most not shown in FIG. 4).Additionally, in an exemplary embodiment, additional defeated Go out passage can include, such as operator interface monitor and/or alarm device (the most not shown in FIG. 4).System controller 108 May also include sensor interface 192, it allows system controller 108 and sensor communication.Sensor interface 192 can include one Or multiple analog-digital converter, it converts analog signals into the digital signal that can be used by processor 182.System controller 108 may also couple to external monitoring systems, such as supervisory control and data acquisition (SCADA) (SCADA) system, such as with utility company and/ Or the SCADA that electric substation or network controller associate.

Fig. 5 is the block diagram of the alternative 200 of the PV electricity generation system including multiple PV collector unit 102.System 100 (illustrating in figs 2 and 3) identifies with identical label with the total parts of system 200.In this embodiment, PV electricity generation system 200 include grid side inverter 104 and system controller 108.PV electricity generation system 200 also includes power transformer 202.Real at this Executing in example, multiple PV collector unit 102 include PV collector unit the 120, the 2nd PV collector unit the 126, the 3rd PV Collector unit 132 and the 4th PV collector unit 138.Multiple PV collector unit 102 each include PV collection device and Single-phase collector side inverter.Described above, a PV collector unit 120 includes being coupled to a PV collection device The first collector side inverter 122 of 124.2nd PV collector unit 126 includes be coupled to the 2nd PV collection device 130 Two collector side inverters 128.3rd PV collector unit 132 includes the 3rd collection being coupled to the 3rd PV collection device 136 Device side inverter 134.4th PV collector unit 138 includes that the 4th collector side being coupled to the 4th PV collection device 142 is inverse Become device 140.

In this embodiment, PV collector unit 102 each can be configured to include any power of unity power factor Factor operation.Additionally, each of multiple PV collector unit 102 also is able in the maximum for inverter/collection device combination Operate at power points.Such as, the first collector side inverter 122 is configured at the maximum work for a PV collection device 124 Operate at rate point.Because each of multiple inverters can operate at different maximum power points, from PV collection device 124, 130,136 and 142 peak power is extracted.

In this embodiment, as shown in fig. 5, power transformer 202 exports three-phase AC from biphase AC.First collects Device unit 120 and the second collector unit 126 couple and provide low pressure AC 260 with the first phase.3rd collector unit 132 and the 4th collector unit 138 couple and provide low pressure AC 262 with the second phase.Power transformer 202 will have Low pressure AC 260 (electric current i.e. provided by a PV collector unit 120 and the 2nd PV collector unit 126) of the first phase and There is low pressure AC 262 (electric current i.e. provided by the 3rd collector unit 132 and the 4th collector unit 138) point of the second phase Become the high pressure three-phase AC 174 of balance in the upper transmission of electrical network 18 (figure 1 illustrates).Power transformer 202 can include, but It is not limited to, Scott-T transformator.

In this embodiment, and as above for described in system 100, grid side inverter 104 makes to be transported to electrical network The voltage stabilization of 18 and adjust this voltage.During the steady state operation of system 200, symmetrical three-phase AC is by grid side inverter 104 provide.During transient affair, such as along during the grid event such as the power surges of electrical network or LVRT event, grid side Inverter 104 is such as by detection and compensation voltage disturbance (by the reactive power led or lag is injected into electrical network 18) It is easy to LVRT.Therefore, grid side inverter 104 can provide PFC.In an exemplary embodiment, system controller 108 provide control signal 176 to perform functions described herein to grid side inverter 104.Additionally, when grid event being detected Time, system controller 108 provides one or more in multiple collector unit 102 of reduction signal, and more specifically, gives At least one in inverter 122,128,134 and 140.System 200 makes necessity between inverter 122,128,134 and 140 Coordination minimizes, thus be conducive to processing about the order of system controller 108 and be easy to from PV collection device 124,130, 136 and 142 produce higher electric power.System 200 is easy at each maximum power point operate multiple collector unit 102, just Connect up and provide during grid event PV to receive in the DC eliminated between collector unit 102 and grid side inverter 104 The Fast Reduction of Collector Units 102.Additionally, when compared with system 100, system 200 reduces wiring complexity.Additionally, be System 200 reduces the quantity of power electronic device required in grid side inverter 104.

Fig. 6 is the block diagram of another alternative 300 of the PV electricity generation system including multiple collector unit 102.? System 100 (illustrating in figs 2 and 3), the identical mark of parts shared between system 200 (figure 4 illustrates) and system 300 Number mark.

In this embodiment, as shown in fig. 6, PV electricity generation system 300 includes system controller 108 and power transformer Device 302.Multiple PV collector unit 102 include that PV collector unit the 301, the 2nd PV collector unit the 312, the 3rd PV receives Collector Units the 314, the 4th PV collector unit the 316, the 5th PV collector unit 318 and the 6th PV collector unit 320.Multiple The each of PV collector unit 102 includes PV collection device and single-phase collector side inverter.Oneth PV collector unit 310 is wrapped Include the first collector side inverter 330 being coupled to a PV collection device 124.2nd PV collector unit 312 includes coupling The second collector side inverter 332 to the 2nd PV collection device 130.3rd PV collector unit 314 includes being coupled to the 3rd 3rd collector side inverter 334 of PV collection device 136.4th PV collector unit 316 includes that being coupled to the 4th PV collects 4th collector side inverter 336 of device 142.5th PV collector unit 318 includes being coupled to the 5th PV collection device 148 The 5th collector side inverter 338.6th PV collector unit 320 includes being coupled to the 6th of the 6th PV collection device 154 Collector side inverter 340.

In this embodiment, each being configured to of PV collector unit 102 is including the wide power factor of unity power factor Scope operates.Multiple PV collector unit 102 can be configured to such as but not limited to from about-0.9 to unity power factor to 0.9 Power factor scope operation.Additionally, each of multiple PV collector unit 102 also is able to for inverter/collection dress Put and operate at the maximum power point of combination.Such as, the first collector side inverter 330 is configured to for a PV collection device Operate at the maximum power point of 124.Because multiple each of inverter 330,332,334,336,338 and 340 can be in difference Maximum power point at operate, from PV collection device 124,130,136,142,148 and 154 extract peak power.

Especially, PV electricity generation system 300 does not include grid side inverter 104.In this embodiment, collector side inverter 330,332,334,336,338 and 340 by specifiedization so that being transported to the voltage stabilization of electrical network 18 (figure 1 illustrates) and adjusting This voltage whole.During the steady state operation of system 300, system controller 108 to collector side inverter 330,332,334, 336, each offer control signal of 338 and 340 is to provide symmetrical three-phase AC 174 to electrical network 18.Additionally, in the transient affair phase Between, collector side inverter 330,332,334,336,338 and 340 such as (passes through high-ranking military officer by detection and compensation voltage disturbance First or delayed reactive power is injected into electrical network 18) and it is easy to LVRT, and therefore PFC is provided.Additionally, catcher Side inverter 330,332,334,336,338 and 340 may be in response to reduce from the reduction signal of system controller 108.System The most controlled the making of system 300 is injected in response to grid condition about actual and reactive power and is produced asymmetrical uneven generating system System.Such as, when the grid condition such as such as load faulty being detected, system controller 108 can provide power factor reference signal To collector side inverter 330,332,334,336,338 and 340.Additionally, collector side inverter 330,332,334,336, 338 and 340 independently in response to including high pressure and the grid condition of low-voltage crossing situation, thus can provide under Var support, frequency Fall response and automatic voltage adjust.System controller 108 provides control signal to optimize the sound of system 300 with low data rate Should, and make the system loss minimization during steady state operation.System controller 108 can also act as data collecting system.

In the embodiment that figure 6 illustrates, multiple PV collector unit 102 export the single-phase AC of low pressure 342, and it is applied to In three conductors (first conductor the 160, second conductor 162 or the 3rd conductor 164) one.As example, the first inverter 330 And the 4th inverter 336 be coupling between the first conductor 160 and the second conductor 162.Second inverter 332 and the 5th inverter 338 are coupling between the second conductor 162 and the 3rd conductor 164.3rd inverter 334 and the 6th inverter 340 are coupling in the 3rd Between conductor 164 and the first conductor 160.Although use triangular arrangement diagram, but first inverter the 330, second inverter 332, the 3rd inverter the 334, the 4th inverter the 336, the 5th inverter 338 and the 6th inverter 340 also can use star like arrangement Coupling.

Conductor 160,162 and 164 is coupled to power transformer 106.Power transformer 106 exports high pressure three-phase AC 174 and uses In being applied to electrical network 18.

Fig. 7 is the exemplary method 410 of the operation for controlling PV electricity generation system 100,200 and 300 (shown in Fig. 2-5) Flow chart 400.More specifically, direct current (DC) electric power is converted into for being transported to electric loading (such as electrical network 18 by method 410 (figure 1 illustrates)) exchange (AC) electric power, wherein DC electric power is by multiple variable input single-phase power supply (such as PV collection devices 124,130,136,142,148 and 154) produce.In an exemplary embodiment, method 410 includes providing more than 420 PV catcher Unit, each of which includes at least one PV battery and collector side single-phase inverter, and these multiple PV collector unit are configured to Produce D/C voltage and this D/C voltage is converted into single-phase AC output.Such as, it is provided that 420PV collector unit 102 (is shown in fig. 2 Go out), and this PV collector unit 102 include produce D/C voltage PV collection device 124,130,136,142,148 and 154, With this D/C voltage is converted to the collector side single-phase inverter 122 of single-phase AC 158 (figure 2 illustrates), 128,134,140, 146 and 152.

In an exemplary embodiment, method 410 also includes at least one system controller (such as system controller 108 (figure 2 illustrates)) it is communicatively coupled 422 to multiple PV collector unit 102.Method 410 also includes system controller 108 Programming 424 is to control the operation of multiple PV collector unit 102.Method 410 may also include and system controller 108 is programmed 426 Reduction signal is sent at least one in multiple PV collector unit 102 when load faulty being detected.

Examples described above is easy to the efficient and cost-effective operation of solar power system.Side described herein Method and system are easy to regulate the electric power for being transported to power distribution network produced by multiple solar collector unit.It is transported to electrical network Electric power realize the expection of electrical network connectedness, it includes but not limited to, stable state and transient state symmetry, the control of reactive power, fault Electric current provides, ramp rate is repaired and grid event is passed through.Capital expenditure, electric power transition loss and line loss are minimized. Method described herein and system are easy to during the temporary derangement of subset or permanent regression of generation assets support electrical network pair Claim.Additionally, embodiment described herein support and control symmetrical and asymmetric fault electric current.

The embodiment of solar power system is describing in detail above.These method and systems are not limited to described herein Specific embodiment, on the contrary, the step of the parts of system and/or method can independently and with miscellaneous part described herein And/or step is used separately.

Although the specific features of various embodiments of the present invention can not illustrate in other figs., this is only For convenience.According to the principle of the present invention, any feature of figure can be come with reference in conjunction with any feature of any other figure and/or want Seek right.

This written description uses example with the open present invention, and it includes optimal mode, and also any skill in making this area Art personnel can put into practice the present invention, including making and using any device or system and perform any method comprised.This Bright the scope of the claims is defined by the claims, and can include other examples that those skilled in that art remember.Such its If his example they there is not different from the written language of claim structural details, if or they include and right The written language required then specifies within the scope of the claims without the equivalent structural elements of substantive difference.

List of parts

Claims (8)

1. a photovoltaic PV electricity generation system, comprising:

Multiple PV collector unit, each in the plurality of PV collector unit includes at least one PV battery and collector side Single-phase inverter, each being configured to couples with electrical network the plurality of PV collector unit via at least one transmission line；

Grid side inverter, is coupling at least one collector side single-phase inverter described of each PV collector unit and described Between electrical network, described grid side inverter is configured to receive the single phase ac exported by each collector side single-phase inverter (AC) and provide heterogeneous AC to described electrical network, and

System controller, is communicably coupled to each PV collector unit and described grid side inverter,

Described system controller is configured to: coordinate each and described grid side inversion of the plurality of PV collector unit individually The operation of device；Be individually controlled every phase of described heterogeneous AC of being applied to described electrical network is applied effectively and reactive power； And at least one controls the plurality of PV to pass through (ZVRT) event by low-voltage crossing (LVRT) event and no-voltage The operation of collector unit.

2. the system as claimed in claim 1 (100), wherein load faulty includes that low-voltage crossing (LVRT) and no-voltage are passed through (ZVRT) at least one in event.

3. the system as claimed in claim 1 (100), wherein said collector side single-phase inverter (122) includes storage operation The memory cell (178) of parameter, described collector side single-phase inverter is configured to the grid condition of measurement and comes At least one in described system controller (108) signal operates according to described operating parameter.

4. system (100) as claimed in claim 3, wherein said operating parameter includes threshold value line voltage power command, electricity Pressure passes through at least one in return command and reactive power command.

5. the system as claimed in claim 1 (100), wherein said multiple PV collector unit (102) are configured to control respectively System is applied to reality and the reactive power of every phase of described heterogeneous AC load (18).

6. the system as claimed in claim 1 (100), wherein said system controller (108) is configured to when load event being detected Carry out during barrier following at least one:

Power factor reference signal is sent at least one in the plurality of PV collector unit (102), and

Reduction signal is sent at least one in the plurality of PV collector unit.

7. the system as claimed in claim 1 (100), each being configured to of wherein said multiple PV collector unit (102) For operating at the maximum power point that each PV collector unit determines, and direct current (DC) voltage is converted to single phase ac (AC) output.

8. system (100) as claimed in claim 7, it farther includes transformator (106), and it is defeated that it is configured to receive single-phase AC Go out and the described single-phase AC from multiple collector side single-phase inverters is exported the heterogeneous AC output being converted into balance.