Method and device for balancing battery power in a multi-machine parallel system

Abstract

The application provides a battery power balancing method and device in a multi-machine parallel system. The method is applied to a target PCS, and the target PCS is any PCS in the multi-machine parallel system. The method comprises the following steps: obtaining a real-time SOC value of a battery cluster corresponding to the target PCS and a real-time frequency of a bus in the multi-machine parallel system; determining a control origin of a droop control curve based on the real-time SOC value, a pre-stored SOC balancing value and a rated power of the target PCS; wherein the control origin is used to indicate an output power of the target PCS at a standard frequency, and the droop control curve is used to indicate output powers of the target PCS at different frequencies; and adjusting the output power of the target PCS based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, so as to balance the battery power in the multi-machine parallel system. The application can balance the battery power in the multi-machine parallel system and ensure safe operation of the multi-machine parallel system.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic power generation technology, and in particular to a method and apparatus for balancing battery power in a multi-machine parallel system. Background Technology

[0002] With the rapid development of new energy industries such as photovoltaic power generation, battery energy storage technology, especially large-scale, high-capacity battery energy storage technology, has received widespread attention and research. A power conversion system (PCS) is the energy link connecting energy storage battery banks and the power grid. Through reasonable charging and discharging control of the energy storage battery banks, the power dispatch requirements of the power grid for the energy storage system can be met.

[0003] When multiple parallel power supply units (PCSs) form a multi-unit parallel system operating off-grid, each PCS operates as a voltage source to power the load. Due to differences in parameters and corresponding battery pack capacities among the PCSs, there are variations in the remaining charge between the battery packs during operation. For example, PCS1 might have a battery pack with a state of charge (SOC) of 50%, while PCS2 might have an SOC of 80%. Allocating the same power to PCS1 and PCS2 could cause PCS1 to shut down due to power deficiency, affecting the safe operation of the multi-unit parallel system. Therefore, how to allocate power among the PCSs during off-grid operation of a multi-unit parallel system is a crucial issue that needs to be addressed. Summary of the Invention

[0004] This invention provides a method and apparatus for balancing battery power in a multi-machine parallel system, which can achieve battery power balancing in the multi-machine parallel system and ensure the safe operation of the multi-machine parallel system.

[0005] In a first aspect, the present invention provides a method for balancing battery power in a multi-machine parallel system, applied to a target PCS, which is any PCS in the multi-machine parallel system. The balancing method includes: acquiring the real-time SOC value of the battery cluster corresponding to the target PCS, and the real-time frequency of the bus in the multi-machine parallel system; determining the control origin of a droop control curve based on the real-time SOC value, a pre-stored SOC balancing value, and the rated power of the target PCS; wherein each PCS stores the same SOC balancing value, the control origin is used to indicate the output power of the target PCS at a standard frequency, and the droop control curve is used to indicate the output power of the target PCS at different frequencies; and adjusting the output power of the target PCS based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system to balance the battery power in the multi-machine parallel system.

[0006] This invention provides a method for balancing battery power in a multi-machine parallel system. Based on the real-time SOC value of the battery cluster corresponding to the target PCS, the balanced SOC value, and the rated power of the target PCS, the control origin of the droop control curve is determined, thus establishing the droop control curve for the target PCS. Then, based on this droop control curve and the real-time frequency of the bus in the multi-machine parallel system, the output power of the target PCS is adjusted. Since the real-time frequency of the bus in the multi-machine parallel system is directly related to the load, the output power of the target PCS determined based on the bus's real-time frequency and the droop control curve can meet the load requirements, achieving a balance between the power provided by the multi-machine parallel system and the load demand. Furthermore, because the control origin of the droop control curve is determined by the real-time SOC value of the battery cluster corresponding to the target PCS, the different battery capacities in the multi-machine parallel system are fully considered. Therefore, the battery power balancing method provided by this invention can achieve battery power balancing in a multi-machine parallel system, ensuring the safe operation of the multi-machine parallel system.

[0007] It should be noted that, compared to schemes that allocate power to each PCS based on load, and schemes that determine the SOC balance value through communication between PCS, the battery power balancing method in a multi-machine parallel system provided by this invention does not require communication with other PCS, nor does it require obtaining the load's required power. The target PCS can independently complete the process of determining its output power, avoiding data transmission processes and simplifying the control logic for battery power balancing in a multi-machine parallel system. Because the data transmission process and control logic in the battery power balancing process of a multi-machine parallel system are complex, errors may occur during the battery power balancing process, affecting system safety. Therefore, the battery power balancing method in a multi-machine parallel system provided by this invention can reduce the probability of errors during the balancing process and improve the safety and reliability of the multi-machine parallel system.

[0008] In one possible implementation, the control origin of the droop control curve is determined based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS. This includes: determining the difference between the real-time SOC value and the SOC equalization value; multiplying the difference by the rated power of the target PCS to determine the output power of the target PCS at the standard frequency; and determining the control origin of the droop control curve based on the standard frequency and the output power of the target PCS at the standard frequency.

[0009] In one possible implementation, the output power of the target PCS is adjusted based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, including: determining the output power corresponding to the real-time frequency based on the droop control curve; and adjusting the target PCS to the output power corresponding to the real-time frequency.

[0010] In one possible implementation, the control origin of the droop control curve is determined based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS. This also includes receiving an externally input control command, which includes the SOC equalization value.

[0011] Secondly, embodiments of the present invention provide a battery power equalization device in a multi-machine parallel system, applied to a target PCS, which is any PCS in the multi-machine parallel system. The equalization device includes: a communication module and a processing module; the communication module is used to acquire the real-time SOC value of the battery cluster corresponding to the target PCS, and the real-time frequency of the bus in the multi-machine parallel system; the processing module is used to determine the control origin of the droop control curve based on the real-time SOC value, a pre-stored equalization SOC value, and the rated power of the target PCS; wherein, each PCS stores the same equalization SOC value, the control origin is used to indicate the output power of the target PCS at a standard frequency, and the droop control curve is used to indicate the output power of the target PCS at different frequencies; based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, the output power of the target PCS is adjusted to equalize the battery power in the multi-machine parallel system.

[0012] In one possible implementation, the processing module is specifically used to determine the difference between the real-time SOC value and the SOC equalization value; multiply the difference by the rated power of the target PCS to determine the output power of the target PCS at the standard frequency; and determine the control origin of the droop control curve based on the standard frequency and the output power of the target PCS at the standard frequency.

[0013] In one possible implementation, the processing module is specifically used to determine the output power corresponding to the real-time frequency based on the droop control curve; and adjust the target PCS to the output power corresponding to the real-time frequency.

[0014] In one possible implementation, the communication module is also used to receive externally input control commands, including SOC equalization values.

[0015] Thirdly, embodiments of the present invention provide an electronic device, characterized in that the electronic device includes a memory and a processor, the memory storing a computer program, and the processor being configured to call and run the computer program stored in the memory to perform the steps of the method as described in the first aspect and any possible implementation thereof.

[0016] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the method as described in the first aspect and any possible implementation thereof.

[0017] The technical effects of any of the implementation methods in the second to fourth aspects mentioned above can be found in the technical effects of the corresponding implementation method in the first aspect, and will not be repeated here. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a scenario for a battery power balancing method in a multi-machine parallel system provided by an embodiment of the present invention;

[0020] Figure 2 This is a flowchart illustrating a method for balancing battery power in a multi-machine parallel system provided by an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of a battery power balancing device in a multi-machine parallel system provided in an embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0023] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0024] In the description of this invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" and "more than one" refer to two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0025] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0026] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include other steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or device.

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the following description will be provided in conjunction with other accompanying drawings and specific embodiments.

[0028] Figure 1 This is a schematic diagram illustrating a method for balancing battery power in a multi-machine parallel system, as provided in an embodiment of the present invention. Figure 1 The architecture of a multi-machine parallel system is shown. This system includes multiple PCS (Power Control Units), battery clusters corresponding to each PCS, energy metering devices, and loads.

[0029] In some embodiments, the PCS is used to convert the energy stored in the battery clusters to power a load. For example, if the load is a DC load, the PCS can perform DC-DC conversion. If the load is an AC load, the PCS can perform DC-AC conversion. Figure 1 The PCS in this context is a DC-AC type energy storage converter.

[0030] In some embodiments, each battery cluster is equipped with a battery management system (BMS) which is responsible for controlling the charging and discharging of the battery cluster and performing functions such as battery cluster state estimation. This enables intelligent management and maintenance of the individual battery cells within the battery cluster, prevents overcharging and over-discharging of the batteries, extends battery life, and monitors battery status.

[0031] In some embodiments, an energy metering device is used to monitor the operating status of a load in real time. For example, the energy metering device can detect the real-time voltage and real-time current of the load, thereby achieving the function of metering the load power.

[0032] It should be noted that during the operation of a multi-unit parallel system, due to differences in the parameters of each PCS and the corresponding battery pack capacity, the output power of each PCS is not the same, resulting in differences in the remaining battery capacity between the battery packs. When the difference in remaining battery capacity between the battery packs is large, some PCS may experience power shortages and shutdowns. After one or more PCSs shut down and leave the system, the load is powered by the remaining PCSs, causing oscillations in the entire multi-unit parallel system and affecting its safe and stable operation.

[0033] To address the aforementioned technical problems, this invention provides a method for balancing battery power in a multi-machine parallel system. To implement this balancing method, an balancing device is installed in each PCS (Power Constraint System) to execute the method. The balancing device acquires the real-time SOC (State of Charge) value of the target PCS, performs calculations to determine the control origin of the droop control curve for the target PCS, and adjusts the output power of the target PCS based on the droop control curve. This achieves battery power balancing and load balancing in the multi-machine parallel system, ensuring the safe and stable operation of the system.

[0034] like Figure 2 As shown, this embodiment of the invention provides a method for balancing battery power in a multi-machine parallel system, applied to a target PCS, which is... Figure 1 Any PCS in the multi-machine parallel system shown. The balancing method includes steps S201-S203.

[0035] S201. Obtain the real-time SOC value of the battery cluster corresponding to the target PCS, and the real-time frequency of the bus in the multi-machine parallel system.

[0036] The target PCS is any one of the multiple PCS in a multi-machine parallel system. For example, such as... Figure 1 As shown, the target PCS can be PCS1, or it can also be PCS2.

[0037] In some embodiments, the state of charge (SOC) is a physical quantity that reflects the remaining capacity of a battery, and its value is the ratio of the remaining charge of the battery to its capacity.

[0038] In some embodiments, the real-time SOC value represents the remaining real-time charge of the battery cluster. For example, the real-time SOC value of PCS1 can be 30%, and the real-time SOC value of PCS2 can be 80%.

[0039] As one possible implementation, the target PCS can send detection information to the corresponding BMS and receive the detection results fed back by the BMS. The detection results include the real-time SOC value.

[0040] For example, PCS1 can send detection information to BMS1. After detecting the real-time SOC value, BMS sends the detection result, including the real-time SOC value, to PCS1, thereby enabling PCS1 to obtain the real-time SOC value.

[0041] As another possible implementation, the target PCS can periodically receive battery cluster status information sent by the corresponding BMS, where the status information includes the real-time SOC value.

[0042] For example, BMS1 can periodically detect the status of the battery clusters and periodically send status information, including the real-time SOC value, to PCS1. This enables PCS1 to obtain the real-time SOC value.

[0043] It should be noted that the real-time frequency of the bus in a multi-machine parallel system is related to the output power and load power of the system. For example, when each PCS in a multi-machine parallel system operates at a first frequency, the sum of the output power of each PCS meets the load requirements. If the load increases, the operating frequency of each PCS in the multi-machine parallel system is adjusted, that is, the real-time frequency of the bus is adjusted, thereby changing the output power of each PCS to meet the increased load requirements.

[0044] As one possible implementation, the control device can directly detect the real-time frequency of the bus through the output of the target PCS.

[0045] S202. Based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS, determine the control origin of the droop control curve.

[0046] Each PCS stores the same SOC equalization value. The control origin is used to indicate the output power of the target PCS at the standard frequency, and the droop control curve is used to indicate the output power of the target PCS at different frequencies.

[0047] It should be noted that the droop control curve is used to represent the relationship between the operating frequency of the PCS and its output power. The control device can adjust the output power of the PCS based on the droop control curve.

[0048] It is understandable that adjusting the droop control curve can change the relationship between the PCS's operating frequency and output power. For example, changing the control origin of the droop control curve can adjust the relationship between the PCS's operating frequency and output power. For instance, increasing or decreasing the PCS's output power at a standard frequency can simultaneously change the relationship between the PCS's operating frequency and output power at other frequencies.

[0049] In this embodiment of the application, the SOC equalization value is used to represent the expected value after the battery power is balanced.

[0050] As one possible implementation, the control device can directly retrieve the pre-stored SOC equalization value from the memory.

[0051] As another possible implementation, before step S202, the control device may receive an externally input control command, which includes the SOC equalization value.

[0052] For example, the SOC equalization value can be 50%, or it can be 60%. This application does not limit it in this regard.

[0053] It is understandable that each PCS stores or receives the same SOC equalization value in advance, so that the battery clusters corresponding to each PCS can be equalized to the same level. Furthermore, the SOC equalization value can be less than the real-time SOC value, indicating that the battery cluster corresponding to the target PCS is in a discharging state during the equalization process. Alternatively, the SOC equalization value can be greater than the real-time SOC value, indicating that the battery cluster corresponding to the target PCS is in a charging state during the equalization process.

[0054] As one possible implementation, the control device can determine the control origin of the droop control curve based on steps A1-A3.

[0055] A1. Determine the difference between the real-time SOC value and the SOC equilibrium value.

[0056] A2. Multiply the difference by the rated power of the target PCS to determine the output power of the target PCS at the standard frequency.

[0057] For example, assuming PCS1 has a real-time SOC of 80%, a balanced SOC of 50%, and a rated power of 10kW, then PCS1's output power at standard frequency is 3kW. Assuming PCS2 has a real-time SOC of 90%, a balanced SOC of 50%, and a rated power of 10kW, then PCS2's output power at standard frequency is 4kW, meaning PCS2's output power is consistently 1kW higher than PCS1's. Assuming PCS3 has a real-time SOC of 20%, a balanced SOC of 50%, and a rated power of 10kW, then PCS3's output power at standard frequency is -3kW, indicating that PCS3 receives charging from other PCSs.

[0058] A3. Based on the standard frequency and the output power of the target PCS at the standard frequency, determine the control origin of the droop control curve.

[0059] For example, the control device can directly determine the standard frequency and the output power of the target PCS at the standard frequency as the control origin of the droop control curve.

[0060] In this way, the control device can determine the control origin of the droop control curve based on the real-time SOC value of the battery cluster corresponding to the target PCS. Thus, different PCS correspond to different control origins, enabling each PCS to determine the control origin of the droop control curve based on the real-time SOC value. This allows each PCS in a multi-machine parallel system to output different power based on the different remaining battery charge of the battery cluster, thereby achieving battery charge balance in the multi-machine parallel system.

[0061] S203. Based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, adjust the output power of the target PCS to balance the battery power in the multi-machine parallel system.

[0062] As one possible implementation, the control device can determine the output power corresponding to the real-time frequency based on the droop control curve, and adjust the target PCS to the output power corresponding to the real-time frequency.

[0063] As another possible implementation, the control device can directly adjust the operating frequency of the target PCS to the real-time frequency of the bus in the multi-machine parallel system based on the droop control curve, thereby completing the adjustment process of the target PCS.

[0064] This invention provides a method for balancing battery power in a multi-machine parallel system. Based on the real-time SOC value of the battery cluster corresponding to the target PCS, the balanced SOC value, and the rated power of the target PCS, the control origin of the droop control curve is determined, thus establishing the droop control curve for the target PCS. Then, based on this droop control curve and the real-time frequency of the bus in the multi-machine parallel system, the output power of the target PCS is adjusted. Since the real-time frequency of the bus in the multi-machine parallel system is directly related to the load, the output power of the target PCS determined based on the bus's real-time frequency and the droop control curve can meet the load requirements, achieving a balance between the power provided by the multi-machine parallel system and the load demand. Furthermore, because the control origin of the droop control curve is determined by the real-time SOC value of the battery cluster corresponding to the target PCS, the different battery capacities in the multi-machine parallel system are fully considered. Therefore, the battery power balancing method provided by this invention can achieve battery power balancing in a multi-machine parallel system, ensuring the safe operation of the multi-machine parallel system.

[0065] It should be noted that, compared to schemes that allocate power to each PCS based on load, and schemes that determine the SOC balance value through communication between PCS, the battery power balancing method in a multi-machine parallel system provided by this invention does not require communication with other PCS, nor does it require obtaining the load's required power. The target PCS can independently complete the process of determining its output power, avoiding data transmission processes and simplifying the control logic for battery power balancing in a multi-machine parallel system. Because the data transmission process and control logic in the battery power balancing process of a multi-machine parallel system are complex, errors may occur during the battery power balancing process, affecting system safety. Therefore, the battery power balancing method in a multi-machine parallel system provided by this invention can reduce the probability of errors during the balancing process and improve the safety and reliability of the multi-machine parallel system.

[0066] It should be understood that the sequence number of each step in the above embodiments does not imply 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 embodiments of the present invention.

[0067] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0068] Figure 3 The diagram shows a schematic of a battery power equalization device in a multi-machine parallel system according to an embodiment of the present invention. The device is applied to a target PCS, which is any PCS in the multi-machine parallel system. The equalization device 300 includes a communication module 301 and a processing module 302.

[0069] The communication module 301 is used to obtain the real-time SOC value of the battery cluster corresponding to the target PCS, as well as the real-time frequency of the bus in the multi-machine parallel system.

[0070] Processing module 302 is used to determine the control origin of the droop control curve based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS. Each PCS stores the same SOC equalization value. The control origin is used to indicate the output power of the target PCS at a standard frequency, and the droop control curve is used to indicate the output power of the target PCS at different frequencies. Based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, the output power of the target PCS is adjusted to balance the battery power in the multi-machine parallel system.

[0071] In one possible implementation, the processing module 302 is specifically used to determine the difference between the real-time SOC value and the SOC equalization value; multiply the difference by the rated power of the target PCS to determine the output power of the target PCS at the standard frequency; and determine the control origin of the droop control curve based on the standard frequency and the output power of the target PCS at the standard frequency.

[0072] In one possible implementation, the processing module 302 is specifically used to determine the output power corresponding to the real-time frequency based on the droop control curve; and adjust the target PCS to the output power corresponding to the real-time frequency.

[0073] In one possible implementation, the communication module 301 is also used to receive externally input control commands, including SOC equalization values.

[0074] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. For example... Figure 4 As shown, the electronic device 400 of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, it implements the steps in the above-described method embodiments, for example... Figure 2 The steps S201 to S203 are shown. Alternatively, when the processor 401 executes the computer program 403, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 3 The functions of the communication module 301 and the processing module 302 shown are illustrated.

[0075] For example, the computer program 403 can be divided into one or more modules / units, which are stored in the memory 402 and executed by the processor 401 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 403 in the electronic device 400. For example, the computer program 403 can be divided into... Figure 3 The communication module 301 and the processing module 302 are shown.

[0076] The processor 401 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), 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.

[0077] The memory 402 can be an internal storage unit of the electronic device 400, such as a hard disk or memory of the electronic device 400. The memory 402 can also be an external storage device of the electronic device 400, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 400. Furthermore, the memory 402 can include both internal and external storage units of the electronic device 400. The memory 402 is used to store the computer program and other programs and data required by the terminal. The memory 402 can also be used to temporarily store data that has been output or will be output.

[0078] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to 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 embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0079] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0080] Those skilled in the art will recognize that the units and algorithm steps of the various examples 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0081] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0082] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0083] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0084] If the integrated module / unit is implemented as 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, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording media, USB flash drives, portable hard drives, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc. It should be noted that the content included in the computer-readable medium can be appropriately added or removed according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electrical carrier signals and telecommunication signals.

[0085] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for balancing battery power in a multi-machine parallel system, characterized in that, The balancing method is applied to a target PCS, which is any PCS in a multi-machine parallel system, and includes: Obtain the real-time SOC value of the battery cluster corresponding to the target PCS, as well as the real-time frequency of the bus in the multi-machine parallel system; Based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS, the control origin of the droop control curve is determined; wherein, each PCS stores the same SOC equalization value, the control origin is used to indicate the output power of the target PCS at a standard frequency, and the droop control curve is used to indicate the output power of the target PCS at different frequencies; the output power of the target PCS at the standard frequency is the product of the difference between the real-time SOC value and the SOC equalization value and the rated power of the target PCS; Based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, the output power of the target PCS is adjusted to balance the battery power in the multi-machine parallel system.

2. The battery power balancing method in a multi-machine parallel system according to claim 1, characterized in that, The step of determining the control origin of the droop control curve based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS includes: Determine the difference between the real-time SOC value and the balanced SOC value; The product of the difference and the rated power of the target PCS is determined as the output power of the target PCS at the standard frequency. The control origin of the droop control curve is determined based on the standard frequency and the output power of the target PCS at the standard frequency.

3. The battery power balancing method in a multi-machine parallel system according to claim 1, characterized in that, The adjustment of the output power of the target PCS based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system includes: Based on the droop control curve, determine the output power corresponding to the real-time frequency; Adjust the output power of the target PCS to the real-time frequency.

4. The method for balancing battery power in a multi-machine parallel system according to any one of claims 1 to 3, characterized in that, The step of determining the control origin of the droop control curve based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS, also includes: Receive externally input control commands, the control commands including the SOC equalization value.

5. A battery power balancing device in a multi-machine parallel system, characterized in that, The equalization device is applied to a target PCS, which is any PCS in a multi-machine parallel system, and includes a communication module and a processing module. The communication module is used to obtain the real-time SOC value of the battery cluster corresponding to the target PCS, as well as the real-time frequency of the bus in the multi-machine parallel system. The processing module is used to determine the control origin of the droop control curve based on the real-time SOC value, the pre-stored SOC equalization value, and the rated power of the target PCS. Each PCS stores the same SOC equalization value. The control origin indicates the output power of the target PCS at a standard frequency, and the droop control curve indicates the output power of the target PCS at different frequencies. The output power of the target PCS at the standard frequency is the product of the difference between the real-time SOC value and the SOC equalization value and the rated power of the target PCS. Based on the droop control curve and the real-time frequency of the bus in the multi-machine parallel system, the output power of the target PCS is adjusted to balance the battery power in the multi-machine parallel system.

6. The battery power equalization device in a multi-machine parallel system according to claim 5, characterized in that, The processing module is specifically used to determine the difference between the real-time SOC value and the SOC equalization value; to multiply the difference by the rated power of the target PCS to determine the output power of the target PCS at the standard frequency; and to determine the control origin of the droop control curve based on the standard frequency and the output power of the target PCS at the standard frequency.

7. The battery power equalization device in a multi-machine parallel system according to claim 5, characterized in that, The processing module is specifically used to determine the output power corresponding to the real-time frequency based on the droop control curve; and to adjust the target PCS to the output power corresponding to the real-time frequency.

8. The battery power equalization device in a multi-machine parallel system according to any one of claims 5 to 7, characterized in that, The communication module is also used to receive externally input control commands, the control commands including the SOC equalization value.

9. An electronic device, characterized in that, The electronic device includes a memory and a processor, the memory storing a computer program, and the processor being configured to invoke and run the computer program stored in the memory to perform the method as described in any one of claims 1 to 4.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method as described in any one of claims 1 to 4 above.

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