Group black start method and device of multi-machine parallel energy storage system and energy storage system

Abstract

The invention provides a group black start method and device of a multi-machine parallel energy storage system and the energy storage system, and belongs to the field of energy storage. The method comprises the following steps: acquiring a positive sequence feedback current average value, a negative sequence feedback current average value and group black start given voltage of the energy storage system; performing current-sharing control based on the positive-sequence feedback current average value and the negative-sequence feedback current average value to obtain a positive-sequence average current control quantity and a negative-sequence average current control quantity; performing positive sequence voltage control based on the positive sequence average current control quantity and group black start given voltage to obtain given output current; based on the negative sequence average current control quantity and the given output current, current control is carried out, and a target control quantity is determined; and controlling the corresponding energy storage converter to perform synchronous black start based on the target control quantity. According to the invention, synchronous black start of each energy storage converter can be realized, sequential start is not needed, a lot of time can be saved, and the power of the energy storage system can reach an expected output level.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a group black start method, device and energy storage system for a multi-machine parallel energy storage system. Background Art

[0002] Black start is the process of restoring power system operation without reliance on external power sources after a complete or partial power outage. Black start is an important means of emergency restoration of power systems, especially after large-scale power outages or natural disasters, to ensure that key facilities and services resume normal operation as soon as possible.

[0003] In the related art, when a multi-machine system performs a black start, each machine is usually started in sequence, that is, after one machine is started, the next machine is started until all machines are started. However, this black start method takes a long time and the power may not reach the expected output level. Summary of the invention

[0004] The embodiments of the present invention provide a group black start method, device and controller for a multi-machine parallel energy storage system to solve the problem that the existing black start method takes a long time and the power is easily unable to reach the expected output level.

[0005] In a first aspect, an embodiment of the present invention provides a group black start method for a multi-machine parallel energy storage system, wherein the energy storage system includes a plurality of parallel energy storage converters, and the group black start method for the multi-machine parallel energy storage system is applied to a controller corresponding to each energy storage converter, including:

[0006] Obtain the average positive-sequence feedback current, average negative-sequence feedback current and group black-start given voltage of the energy storage system;

[0007] Based on the average value of the positive sequence feedback current and the average value of the negative sequence feedback current, current sharing control is performed to obtain the positive sequence average current control amount and the negative sequence average current control amount;

[0008] Based on the positive sequence average current control amount and the group black start given voltage, the positive sequence voltage control is performed to obtain the given output current;

[0009] Based on the negative sequence average current control amount and the given output current, current control is performed to determine the target control amount;

[0010] Based on the target control amount, the corresponding energy storage converter is controlled to perform a synchronous black start, so that all energy storage converters of the energy storage system are synchronously black started.

[0011] In a possible implementation, positive sequence voltage control is performed based on the positive sequence average current control amount and the group black start given voltage to obtain a given output current, including:

[0012] The positive sequence average current control amount is superimposed on the group black start given voltage, and the positive sequence voltage control is performed to obtain the given output current.

[0013] In a possible implementation, current control is performed based on the negative sequence average current control amount and a given output current to determine a target control amount, including:

[0014] Performing negative-sequence voltage control on the negative-sequence average current control quantity to obtain a first positive-sequence control quantity;

[0015] The first positive sequence control amount is superimposed on the given output current, and current control is performed to determine the target control amount.

[0016] In a possible implementation, current sharing control is performed based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain the positive-sequence average current control amount and the negative-sequence average current control amount, including:

[0017] Perform positive-sequence current sharing control on the average value of the positive-sequence feedback current to obtain the positive-sequence average current control value;

[0018] The negative-sequence feedback current average value is subjected to negative-sequence current sharing control to obtain the negative-sequence average current control value.

[0019] In one possible implementation, when a new energy storage inverter is incorporated into the energy storage system during a group black start of the energy storage system, a control method for each current energy storage inverter in the energy storage system is used to control the new energy storage inverter so that the new energy storage inverter maintains voltage synchronization and current sharing with each current energy storage inverter in the energy storage system.

[0020] In a possible implementation, the average value of the positive-sequence feedback current is the average value of the positive-sequence feedback current of each energy storage converter in the energy storage system; and the average value of the negative-sequence feedback current is the average value of the negative-sequence feedback current of each energy storage converter in the energy storage system.

[0021] In a possible implementation, controlling the corresponding energy storage converter to perform a synchronous black start based on the target control amount includes:

[0022] Perform drive control on the target control quantity and determine the drive control signal;

[0023] Based on the drive control signal, the corresponding energy storage converter is controlled to perform a synchronous black start.

[0024] In a second aspect, an embodiment of the present invention provides a group black start device for a multi-machine parallel energy storage system, wherein the energy storage system includes a plurality of parallel energy storage converters, and the group black start device for the multi-machine parallel energy storage system is applied to a controller corresponding to each energy storage converter, including:

[0025] An acquisition module is used to obtain the average value of the positive-sequence feedback current, the average value of the negative-sequence feedback current and the group black-start given voltage of the energy storage system;

[0026] A current sharing control module is used to perform current sharing control based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain a positive-sequence average current control amount and a negative-sequence average current control amount;

[0027] A voltage control module is used to perform positive sequence voltage control based on the positive sequence average current control amount and the group black start given voltage to obtain a given output current;

[0028] A current control module is used to perform current control and determine a target control amount based on a negative sequence average current control amount and a given output current;

[0029] The synchronous black start control module is used to control the corresponding energy storage converter to perform a synchronous black start based on the target control amount, so that all energy storage converters of the energy storage system can perform a synchronous black start.

[0030] In a third aspect, an embodiment of the present invention provides a controller comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the group black start method of a multi-machine parallel energy storage system as described in the first aspect or any possible implementation method of the first aspect.

[0031] In a fourth aspect, an embodiment of the present invention provides an energy storage system, comprising a plurality of energy storage converters connected in parallel, and a controller as described in the third aspect corresponding to the energy storage converter; the energy storage converter is controlled by the corresponding controller.

[0032] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the group black start method of a multi-machine parallel energy storage system as described in the first aspect or any possible implementation method of the first aspect are implemented.

[0033] The embodiment of the present invention provides a group black start method, device and energy storage system of a multi-machine parallel energy storage system. The method performs current sharing control based on the average value of positive-sequence feedback current and the average value of negative-sequence feedback current to obtain the positive-sequence average current control amount and the negative-sequence average current control amount, and then performs positive-sequence voltage control based on the positive-sequence average current control amount and the group black start given voltage to obtain a given output current. Then, current control is performed based on the negative-sequence average current control amount and the given output current to determine a target control amount. Finally, the corresponding energy storage converter is controlled to perform a synchronous black start based on the target control amount, so that all energy storage converters of the energy storage system are synchronously black started, which can realize voltage synchronization control and current sharing control of each energy storage converter of the energy storage system, so that each energy storage converter can be synchronously black started without starting in sequence, which can save a lot of time and ensure that the power of the energy storage system can reach the expected output level. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 is a flow chart for implementing a group black start method of a multi-machine parallel energy storage system provided by an embodiment of the present invention;

[0036] Figure 2 It is a schematic diagram of a control loop corresponding to a group black start method of a multi-machine parallel energy storage system provided by an embodiment of the present invention;

[0037] Figure 3 is a structural schematic diagram of a group black start device for a multi-machine parallel energy storage system provided by an embodiment of the present invention;

[0038] Figure 4 is a schematic diagram of a controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0041] See also Figure 1 , which shows an implementation flow chart of the group black start method of the multi-machine parallel energy storage system provided by an embodiment of the present invention. The multi-machine parallel energy storage system can be referred to as an energy storage system. The energy storage system includes a plurality of parallel energy storage converters (Power Conversion System, PCS). The number of energy storage converters in the energy storage system can be set according to actual needs without specific restrictions. Each energy storage converter in the energy storage system is controlled by the group black start method of the multi-machine parallel energy storage system to achieve group black start or synchronous black start.

[0042] The executor of the group black start method of the above-mentioned multi-machine parallel energy storage system may be a control device. In one embodiment, the control device may be a master controller in the energy storage system, and each energy storage converter is controlled by the master controller. The master controller uses the above-mentioned method to control each energy storage converter respectively to achieve group black start. It should be noted that when the master controller uses the above-mentioned method to control each energy storage converter respectively, the required feedback parameters are the feedback parameters of the corresponding energy storage converter. For example, to control energy storage converter A, the feedback parameters required in the method are usually the feedback parameters of energy storage converter A. Feedback parameters may include feedback current, feedback voltage, etc., and may also include other required feedback parameters. Feedback parameters may also be called sampling parameters, which can be understood as the actual values ​​of the parameters of the energy storage converter.

[0043] In another embodiment, the control device may also be a controller corresponding to each energy storage inverter in the energy storage system. Each controller simultaneously uses the above-mentioned group black start method of the multi-machine parallel energy storage system to control the corresponding energy storage inverter to achieve group black start. In other words, the above method is applied to the controller corresponding to each energy storage inverter in the energy storage system. It should be noted that when the controller uses the above method to control the corresponding energy storage inverter, the required feedback parameter is the feedback parameter of the corresponding energy storage inverter.

[0044] The following takes the control device being the controller corresponding to each energy storage converter in the energy storage system as an example for detailed description.

[0045] See also Figure 1 , the method is described in detail as follows:

[0046] In S101, the average value of the positive-sequence feedback current, the average value of the negative-sequence feedback current and the group black-start given voltage of the energy storage system are obtained.

[0047] The average value of the positive-sequence feedback current of the energy storage system is the average value of the positive-sequence feedback current of each energy storage converter in the energy storage system; the average value of the negative-sequence feedback current of the energy storage system is the average value of the negative-sequence feedback current of each energy storage converter in the energy storage system.

[0048] The embodiments of the present application do not impose specific restrictions on the means for obtaining the positive-sequence feedback current and the negative-sequence feedback current of each energy storage converter. After summing the positive-sequence feedback current of each energy storage converter, the sum is divided by the number of energy storage converters to obtain the average value of the positive-sequence feedback current. After summing the negative-sequence feedback current of each energy storage converter, the sum is divided by the number of energy storage converters to obtain the average value of the negative-sequence feedback current. The calculation process of the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current can be implemented in the main controller and then sent to the controller corresponding to each energy storage converter, or it can be directly implemented in the controller corresponding to each energy storage converter.

[0049] The group black start given voltage of the energy storage system can also be called the group black start reference voltage of the energy storage system, which refers to the voltage that each energy storage converter in the energy storage system needs to reach for group black start. The group black start given voltage can include a given voltage amplitude and a given phase. The group black start given voltages of each energy storage converter in the energy storage system are the same, so that voltage synchronization control can be achieved.

[0050] In some possible implementations, each energy storage converter of the energy storage system adopts a slow start mode when performing group black start. Based on the slow start mode, the group black start given voltage of the above energy storage system can be gradually increased from 0 until the voltage when the energy storage converter works normally. In other words, the group black start given voltages of each energy storage converter are increased synchronously.

[0051] The group black start given voltage of the above energy storage system can be sent by the main controller to the controllers corresponding to each energy storage inverter. After the controllers corresponding to each energy storage inverter receive it for the first time, they start to execute the above method. Thereafter, each time a new group black start given voltage is received, the new group black start given voltage is used for control.

[0052] In some possible implementations, the above S101 may include:

[0053] When a group black start instruction is received, the average value of the positive sequence feedback current, the average value of the negative sequence feedback current and the group black start given voltage of the energy storage system are obtained to achieve a synchronous black start.

[0054] In S102, current sharing control is performed based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain a positive-sequence average current control amount and a negative-sequence average current control amount.

[0055] The embodiment of the present application can perform current sharing control based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current, so as to obtain the positive-sequence average current control amount and the negative-sequence average current control amount of the corresponding energy storage converter. The positive-sequence average current control amount can be used for positive-sequence voltage control. The negative-sequence average current control amount can be converted to the positive-sequence timing for current control.

[0056] The embodiment of the present application does not impose any specific restrictions on the specific implementation means for performing current sharing control based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain the positive-sequence average current control amount and the negative-sequence average current control amount, and any achievable means may be used.

[0057] In S103, positive sequence voltage control is performed based on the positive sequence average current control amount and the group black start given voltage to obtain a given output current.

[0058] Among them, the group black start given voltage can be used as the given output voltage of each energy storage converter, and at the same time, combined with the positive sequence average current control amount, the positive sequence voltage control is performed to obtain the given output current of the corresponding energy storage converter. Since the group black start given voltage includes a given voltage amplitude and a given phase, the same group black start given voltage is used for control to achieve the synchronization of the voltage amplitude and voltage phase of each energy storage converter.

[0059] In S104, current control is performed based on the negative-sequence average current control amount and the given output current to determine the target control amount.

[0060] The embodiment of the present application can perform current control according to the average current control amount and the given output current, thereby obtaining the target control amount of the corresponding energy storage converter. The target control amount can be used to generate a corresponding drive control signal for controlling the corresponding energy storage converter.

[0061] The embodiment of the present application does not impose any specific restrictions on the specific means of implementing current control and determining the target control amount based on the negative-sequence average current control amount and a given output current, and any achievable means may be used.

[0062] In S105 , the corresponding energy storage converter is controlled to perform a synchronous black start based on the target control amount, so that all energy storage converters of the energy storage system are synchronously black started.

[0063] The embodiment of the present application performs synchronous black start control on the corresponding energy storage converter based on the target control amount. Since the controller corresponding to each energy storage converter of the energy storage system synchronously executes the method provided in the embodiment of the present application to achieve synchronous black start control of the corresponding energy storage converter, all energy storage converters of the energy storage system can achieve synchronous black start.

[0064] The embodiment of the present application performs current sharing control based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain the positive-sequence average current control amount and the negative-sequence average current control amount, and then performs positive-sequence voltage control based on the positive-sequence average current control amount and the group black-start given voltage to obtain a given output current, and then performs current control based on the negative-sequence average current control amount and the given output current to determine the target control amount, and finally controls the corresponding energy storage converter to perform a synchronous black-start based on the target control amount, so that all energy storage converters of the energy storage system are synchronously black-started, which can realize voltage synchronization control and current sharing control of each energy storage converter of the energy storage system, so that each energy storage converter can be synchronously black-started without starting in sequence, which can save a lot of time and at the same time can ensure that the power of the energy storage system can reach the expected output level.

[0065] In some embodiments, the above S102 may include:

[0066] Perform positive-sequence current sharing control on the average value of the positive-sequence feedback current to obtain the positive-sequence average current control value;

[0067] The negative-sequence feedback current average value is subjected to negative-sequence current sharing control to obtain the negative-sequence average current control value.

[0068] See also Figure 2 In the control loop shown, the average values ​​of the positive and negative sequence feedback currents include the above-mentioned average value of the positive sequence feedback current and the above-mentioned average value of the negative sequence feedback current.

[0069] By performing positive-sequence current sharing control on the average value of the positive-sequence feedback current, the positive-sequence average current control amount can be obtained. Specifically, the positive-sequence feedback current of the corresponding energy storage converter can be obtained, the first difference between the average value of the positive-sequence feedback current and the positive-sequence feedback current can be calculated, and the first difference can be input into the first preset proportional-integral controller to obtain the above-mentioned positive-sequence average current control amount. Among them, the relevant parameters in the first preset proportional-integral controller have been preset and can be set according to actual needs.

[0070] By performing negative-sequence current sharing control on the average value of the negative-sequence feedback current, the negative-sequence average current control amount can be obtained. Specifically, the negative-sequence feedback current of the corresponding energy storage converter can be obtained, the second difference between the average value of the negative-sequence feedback current and the negative-sequence feedback current can be calculated, and the second difference can be input into the second preset proportional-integral controller to obtain the above-mentioned negative-sequence average current control amount. Among them, the relevant parameters in the second preset proportional-integral controller have been preset and can be set according to actual needs.

[0071] In some embodiments, the above S103 may include:

[0072] The positive sequence average current control amount is superimposed on the group black start given voltage, and the positive sequence voltage control is performed to obtain the given output current.

[0073] See also Figure 2 In the control loop shown, the positive sequence average current control amount can be superimposed on the group black start given voltage, that is, the above positive sequence average current control amount and the group black start given voltage are summed to obtain the superimposed given voltage of the corresponding energy storage converter. Based on the superimposed given voltage, positive sequence voltage control is performed to obtain the given output current of the corresponding energy storage converter.

[0074] Exemplarily, the feedback voltage of the corresponding energy storage converter can be obtained, and the feedback voltage is the feedback output voltage; the third difference between the superimposed given voltage and the feedback voltage is calculated, and the third difference is input into the third preset proportional integral controller to obtain the above-mentioned given output current. Among them, the relevant parameters in the third preset proportional integral controller have been preset and can be set according to actual needs.

[0075] In some possible implementations, the output end of the parallel energy storage converter can be connected to a transformer, so that the conversion from three-phase three-wire to three-phase four-wire can be realized. Based on this structure, the above-mentioned group black start given voltage can be determined according to the given output voltage of the transformer. Specifically, the feedback voltage of the transformer is obtained, the fourth difference between the given output voltage of the transformer and the feedback voltage of the transformer is calculated, and the fourth difference is input into the fourth preset proportional integral controller to obtain the above-mentioned group black start given voltage. Among them, the relevant parameters in the fourth preset proportional integral controller have been preset and can be set according to actual needs.

[0076] In some possible implementations, the positive-sequence average current control amount, the voltage DC component control amount and the current DC component control amount may be superimposed on the group black start given voltage, and positive-sequence voltage control may be performed to obtain a given output current.

[0077] In some embodiments, the above S104 may include:

[0078] Performing negative-sequence voltage control on the negative-sequence average current control quantity to obtain a first positive-sequence control quantity;

[0079] The first positive sequence control amount is superimposed on the given output current, and current control is performed to determine the target control amount.

[0080] The above-mentioned negative-sequence voltage control of the negative-sequence average current control amount to obtain the first positive-sequence control amount may include: obtaining the negative-sequence feedback voltage of the corresponding energy storage converter, calculating the fifth difference between the negative-sequence average current control amount of the corresponding energy storage converter and the negative-sequence feedback voltage of the corresponding energy storage converter, and inputting the fifth difference into the fifth preset proportional-integral controller to obtain the first negative-sequence control amount of the corresponding energy storage converter, and converting the first negative-sequence control amount to the positive-sequence timing to obtain the first positive-sequence control amount of the corresponding energy storage converter. The relevant parameters in the fifth preset proportional-integral controller have been pre-set and can be set according to actual needs.

[0081] See also Figure 2 In the control loop shown, the first positive sequence control amount can be superimposed on the given output current of the corresponding energy storage converter, that is, the first positive sequence control amount and the given output current are summed to obtain the superimposed given output current of the corresponding energy storage converter. Based on the superimposed given output current, current control is performed to obtain the target control amount of the corresponding energy storage converter.

[0082] Exemplarily, the feedback output current of the corresponding energy storage converter can be obtained; the sixth difference between the superimposed given output current and the feedback output current is calculated, and the sixth difference is input into the sixth preset proportional integral controller to obtain the above-mentioned target control amount. Among them, the relevant parameters in the sixth preset proportional integral controller have been preset and can be set according to actual needs.

[0083] The embodiment of the present application obtains a positive-sequence average current control amount and a negative-sequence average current control amount through the above-mentioned current balancing control, and superimposes the positive-sequence average current control amount on the group black start given voltage to perform positive-sequence voltage control, and superimposes the first positive-sequence control amount obtained by performing negative-sequence voltage control on the above-mentioned negative-sequence average current control amount on the given output current to perform current control, thereby achieving current balancing control of each energy storage inverter.

[0084] In some embodiments, when a new energy storage inverter is incorporated into the energy storage system during a group black start of the energy storage system, a control method for each current energy storage inverter in the energy storage system is used to control the new energy storage inverter so that the new energy storage inverter maintains voltage synchronization and current sharing with each current energy storage inverter in the energy storage system.

[0085] In an embodiment of the present application, when the energy storage system performs a group black start, a new energy storage converter can be incorporated into the energy storage system at any time during the black start process and participate in the group black start. The newly incorporated energy storage converter is controlled by the same group black start given voltage and the same method, so that the newly incorporated energy storage converter is under the same closed-loop control quantity, ensuring that the output voltage is synchronized with other energy storage converters, and after the same current sharing control, ensuring that the newly incorporated energy storage converter shares current with other energy storage converters, thereby achieving voltage synchronization and current sharing of all energy storage converters in the energy storage system.

[0086] In some embodiments, in the above S105, controlling the corresponding energy storage converter to perform a synchronous black start based on the target control amount includes:

[0087] Perform drive control on the target control quantity and determine the drive control signal;

[0088] Based on the drive control signal, the corresponding energy storage converter is controlled to perform a synchronous black start.

[0089] The above-mentioned drive control of the target control amount and determination of the drive control signal may include: summing the above-mentioned target control amount and the feedback output voltage of the corresponding energy storage converter, normalizing the summed voltage to obtain a target duty cycle, and generating a drive control signal based on the target duty cycle.

[0090] Based on the drive control signal, the corresponding energy storage converter is controlled.

[0091] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0092] Figure 3 The schematic diagram of the structure of the group black start device of the multi-machine parallel energy storage system provided by the embodiment of the present invention is shown. For the convenience of explanation, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0093] The energy storage system includes multiple parallel energy storage converters. The group black start device of the multi-machine parallel energy storage system is applied to the controller corresponding to each energy storage converter in the energy storage system, such as Figure 3 As shown, the group black start device 30 of the multi-machine parallel energy storage system includes: an acquisition module 31, a current sharing control module 32, a voltage control module 33, a current control module 34 and a synchronous black start control module.

[0094] An acquisition module 31 is used to acquire an average positive-sequence feedback current, an average negative-sequence feedback current and a group black-start given voltage of the energy storage system;

[0095] The current sharing control module 32 is used to perform current sharing control based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain the positive-sequence average current control amount and the negative-sequence average current control amount;

[0096] The voltage control module 33 is used to perform positive sequence voltage control based on the positive sequence average current control amount and the group black start given voltage to obtain a given output current;

[0097] The current control module 34 is used to perform current control and determine a target control amount based on the negative sequence average current control amount and a given output current;

[0098] The synchronous black start control module 35 is used to control the corresponding energy storage converter to perform a synchronous black start based on the target control amount, so that all energy storage converters of the energy storage system can perform a synchronous black start.

[0099] In a possible implementation, the voltage control module 33 is specifically used to:

[0100] The positive sequence average current control amount is superimposed on the group black start given voltage, and the positive sequence voltage control is performed to obtain the given output current.

[0101] In a possible implementation, the current control module 34 is specifically used to:

[0102] Performing negative-sequence voltage control on the negative-sequence average current control quantity to obtain a first positive-sequence control quantity;

[0103] The first positive sequence control amount is superimposed on the given output current, and current control is performed to determine the target control amount.

[0104] In a possible implementation, the current sharing control module 32 is specifically used for:

[0105] Perform positive-sequence current sharing control on the average value of the positive-sequence feedback current to obtain the positive-sequence average current control value;

[0106] The negative-sequence feedback current average value is subjected to negative-sequence current sharing control to obtain the negative-sequence average current control value.

[0107] In one possible implementation, when a new energy storage inverter is incorporated into the energy storage system during a group black start of the energy storage system, a control method for each current energy storage inverter in the energy storage system is used to control the new energy storage inverter so that the new energy storage inverter maintains voltage synchronization and current sharing with each current energy storage inverter in the energy storage system.

[0108] In a possible implementation, the average value of the positive-sequence feedback current is the average value of the positive-sequence feedback current of each energy storage converter in the energy storage system; and the average value of the negative-sequence feedback current is the average value of the negative-sequence feedback current of each energy storage converter in the energy storage system.

[0109] In a possible implementation, the synchronous black start control module 35 is specifically used for:

[0110] Perform drive control on the target control quantity and determine the drive control signal;

[0111] Based on the drive control signal, the corresponding energy storage converter is controlled to perform a synchronous black start.

[0112] Figure 4 is a schematic diagram of a controller provided by an embodiment of the present invention. Figure 4 As shown, the controller 4 of this embodiment includes: a processor 40 and a memory 41. The memory 41 is used to store a computer program 42, and the processor 40 is used to call and run the computer program 42 stored in the memory 41 to execute the steps in the above-mentioned group black start method embodiments of each multi-machine parallel energy storage system, such as Figure 1 Alternatively, the processor 40 is used to call and run the computer program 42 stored in the memory 41 to implement the functions of each module / unit in the above-mentioned device embodiments, for example Figure 3 The functions of each module are shown.

[0113] Exemplarily, the computer program 42 may be divided into one or more modules / units, which are stored in the memory 41 and executed by the processor 40 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 42 in the controller 4. For example, the computer program 42 may be divided into Figure 3 The modules shown.

[0114] The controller 4 may include, but is not limited to, a processor 40 and a memory 41. Those skilled in the art will appreciate that Figure 4 This is only an example of the controller 4 and does not constitute a limitation on the controller 4. The controller 4 may include more or fewer components than shown in the figure, or may combine certain components, or may have different components. For example, the controller may also include input and output devices, network access devices, buses, etc. For example, the controller may also include the aforementioned DMS and OMS, etc.

[0115] The processor 40 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0116] The memory 41 may be an internal storage unit of the controller 4, such as a hard disk or memory of the controller 4. The memory 41 may also be an external storage device of the controller 4, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the controller 4. Further, the memory 41 may also include both an internal storage unit of the controller 4 and an external storage device. The memory 41 is used to store the computer program and other programs and data required by the controller. The memory 41 may also be used to temporarily store data that has been output or is to be output.

[0117] Corresponding to the above-mentioned controller, an embodiment of the present invention further provides an energy storage system, including a plurality of energy storage converters connected in parallel, and the above-mentioned controller corresponding to the energy storage converter; the energy storage converter is controlled by the corresponding controller.

[0118] For the relevant description of the energy storage system, please refer to the description in the aforementioned embodiment and will not be repeated here.

[0119] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0120] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0121] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0122] In the embodiments provided by the present invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0123] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0124] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0125] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the group black start method embodiment of each multi-machine parallel energy storage system can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0126] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A group black start method for a multi-machine parallel energy storage system, characterized in that: The energy storage system includes a plurality of energy storage converters connected in parallel. The method is applied to a controller corresponding to each energy storage converter, including: Obtaining an average positive-sequence feedback current, an average negative-sequence feedback current, and a group black-start given voltage of the energy storage system; Based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current, current sharing control is performed to obtain a positive-sequence average current control amount and a negative-sequence average current control amount; Based on the positive sequence average current control amount and the group black start given voltage, positive sequence voltage control is performed to obtain a given output current; Based on the negative sequence average current control amount and the given output current, current control is performed to determine a target control amount; Based on the target control amount, the corresponding energy storage converter is controlled to perform a synchronous black start, so that all energy storage converters of the energy storage system are synchronously black started.

2. The group black start method of a multi-machine parallel energy storage system according to claim 1, characterized in that: The method of performing positive sequence voltage control based on the positive sequence average current control amount and the group black start given voltage to obtain a given output current includes: The positive sequence average current control amount is superimposed on the group black start given voltage, and positive sequence voltage control is performed to obtain a given output current.

3. The group black start method of a multi-machine parallel energy storage system according to claim 1, characterized in that: The performing current control based on the negative sequence average current control amount and the given output current to determine the target control amount includes: Performing negative-sequence voltage control on the negative-sequence average current control amount to obtain a first positive-sequence control amount; The first positive sequence control amount is superimposed on the given output current, and current control is performed to determine a target control amount.

4. The group black start method of a multi-machine parallel energy storage system according to claim 1, characterized in that: The current sharing control is performed based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current to obtain the positive-sequence average current control amount and the negative-sequence average current control amount, including: Performing positive-sequence current sharing control on the average value of the positive-sequence feedback current to obtain a positive-sequence average current control amount; The negative-sequence feedback current average value is subjected to negative-sequence current sharing control to obtain a negative-sequence average current control amount.

5. The group black start method of a multi-machine parallel energy storage system according to claim 1, characterized in that: When a new energy storage inverter is incorporated into the energy storage system during the group black start of the energy storage system, a control method for each current energy storage inverter in the energy storage system is adopted to control the new energy storage inverter so that the new energy storage inverter maintains voltage synchronization and current sharing with each current energy storage inverter in the energy storage system.

6. The group black start method of a multi-machine parallel energy storage system according to any one of claims 1 to 5, characterized in that: The average value of the positive-sequence feedback current is the average value of the positive-sequence feedback current of each energy storage converter in the energy storage system; the average value of the negative-sequence feedback current is the average value of the negative-sequence feedback current of each energy storage converter in the energy storage system.

7. The group black start method of a multi-machine parallel energy storage system according to any one of claims 1 to 5, characterized in that: The controlling the corresponding energy storage converter to perform a synchronous black start based on the target control amount includes: Performing drive control on the target control amount to determine a drive control signal; Based on the drive control signal, the corresponding energy storage converter is controlled to perform a synchronous black start.

8. A group black start device for a multi-machine parallel energy storage system, characterized in that: The energy storage system includes a plurality of energy storage converters connected in parallel, and the device is applied to a controller corresponding to each energy storage converter, including: An acquisition module, used for acquiring an average value of a positive-sequence feedback current, an average value of a negative-sequence feedback current and a group black-start given voltage of the energy storage system; A current sharing control module, used to perform current sharing control based on the average value of the positive-sequence feedback current and the average value of the negative-sequence feedback current, to obtain a positive-sequence average current control amount and a negative-sequence average current control amount; A voltage control module, used for performing positive sequence voltage control based on the positive sequence average current control amount and the group black start given voltage to obtain a given output current; A current control module, used to perform current control and determine a target control amount based on the negative sequence average current control amount and the given output current; The synchronous black start control module is used to control the corresponding energy storage converter to perform a synchronous black start based on the target control amount, so that all energy storage converters of the energy storage system can perform a synchronous black start.

9. A controller, characterized in that: It comprises a memory and a processor, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the group black start method of a multi-machine parallel energy storage system as described in any one of claims 1 to 7.

10. An energy storage system, characterized in that: It comprises a plurality of energy storage converters connected in parallel, and a controller as claimed in claim 9 corresponding to the energy storage converters; the energy storage converters are controlled by the corresponding controllers.

Images