Balancing control method and device of energy storage power station considering soc feedback

Abstract

The application discloses a kind of equalization control method and device of energy storage power station considering SOC feedback, wherein the method includes measuring the terminal voltage of energy storage unit, the SOC value of energy storage unit is calculated in combination with the terminal voltage and voltage characteristic curve;SOC value is compared with threshold range, and the power interval of energy storage unit is determined according to the comparison result;Threshold range represents the critical value of safe operation of energy storage unit;According to the power interval of energy storage unit, the corresponding charge-discharge power limitation is carried out, to realize the equalization of different energy storage unit SOC.The present application carries out charge-discharge power limitation according to the power interval of energy storage unit, to realize the equalization of different energy storage unit SOC, to avoid overcharge and overdischarge.

Description

Technical Field

[0001] This application relates to the field of power systems, and in particular to a method and apparatus for equalization control of an energy storage power station considering SOC feedback, specifically used for equalization control of an energy storage power station. Background Technology

[0002] In existing energy storage power station control technologies, the front-end of the power station must output a certain voltage level to meet the requirements of the downstream three-phase IGBT inverter. Currently, most energy storage power stations use batteries as the basic energy storage unit.

[0003] When a battery is used as an energy storage unit, its SOC value will gradually decrease as the discharge process proceeds. During short-term discharge, the output voltage of the battery operating in the linear region will not change significantly. However, as the discharge time increases, the SOC of the battery will continue to decrease, resulting in a continuous decrease in the output voltage of the battery and a low quality of power output from the energy storage station. Summary of the Invention

[0004] This invention discloses a method, apparatus, equipment, and storage medium for equalization control of an energy storage power station that considers SOC feedback, in order to at least solve the above-mentioned technical problems existing in the prior art.

[0005] According to a first aspect of this application, a method for equalization control of an energy storage power station considering SOC feedback is provided, the method comprising:

[0006] Measure the terminal voltage of the energy storage unit, and calculate the SOC value of the energy storage unit by combining the terminal voltage and the voltage characteristic curve;

[0007] The SOC value is compared with a threshold range, and the energy range in which the energy storage unit operates is determined based on the comparison result; the threshold range represents the critical value for the safe operation of the energy storage unit.

[0008] The charging and discharging power is limited according to the operating power range of the energy storage unit in order to achieve a balance of the SOC of different energy storage units.

[0009] In one embodiment, the energy storage unit includes multiple units, and the calculation of the SOC value of the energy storage unit by combining the terminal voltage and voltage characteristic curve includes:

[0010] Determine the voltage characteristic curve for each energy storage unit;

[0011] Based on the voltage characteristic curve and the terminal voltage, the SOC value of the energy storage unit at the corresponding time is obtained.

[0012] In one possible implementation, the threshold range includes: the maximum critical value soc for safe operation of a single energy storage unit. maxThe minimum critical value (SOC) for safe operation of a single energy storage unit min The highest critical value (SOC) for unrestricted operation of a single energy storage unit. high The minimum critical value of SOC for unrestricted operation of a single energy storage unit. low ;

[0013] Among them, the highest critical value of SOC for unrestricted operation of a single energy storage unit. high The SOC value is greater than the maximum critical value for safe operation of a single energy storage unit. max The minimum critical value (SOC) for safe operation of a single energy storage unit min Less than the minimum critical value of SOC for unrestricted operation of a single energy storage unit low .

[0014] In one possible implementation, comparing the SOC value with a threshold range and determining the energy range in which the energy storage unit operates based on the comparison result includes:

[0015] When the SOC value is greater than soc min At this time, the energy storage unit operates in the deep charging range;

[0016] When the SOC value is less than soc min At that time, the energy storage unit operates in the deep discharge range;

[0017] When the SOC value is greater than soc high And the SOC value is less than soc max hour,

[0018] When the SOC value is greater than soc min And the SOC value is less than soc low At that time, the energy storage unit operates in the low-power range;

[0019] When the SOC value is greater than soc low And the SOC value is less than soc high At that time, the energy storage unit operates in the equilibrium range.

[0020] In one possible implementation, charging the energy storage unit is prohibited when the energy storage unit is operating in the deep charging range;

[0021] When the energy storage unit is operating in the deep discharge range, the energy storage unit is prohibited from continuing to discharge;

[0022] When the energy storage unit operates in the high-capacity range, the charging power of the energy storage unit is limited by the control system.

[0023] When the energy storage unit operates in the low-power range, the discharge power of the energy storage unit is limited by the control system.

[0024] When the energy storage unit operates in the equilibrium range, the charging and discharging power of the energy storage unit is not limited by the control system.

[0025] In one possible implementation, the charging and discharging power is limited according to the energy range in which the energy storage unit operates, including:

[0026] For energy storage units operating in the high-capacity range, the charging current is limited to limit the charging power;

[0027] For energy storage units operating in the low-power range, the discharge current is limited to restrict the discharge power.

[0028] In one possible implementation, for energy storage units operating in the high-capacity range, the charging current is limited using the following method:

[0029]

[0030] Where n represents the total number of energy storage units on the DC side of the energy storage power station; I sat (x) represents the output current limiting value of a certain energy storage unit; U DC (x) represents the terminal voltage of a certain energy storage unit; soc(x) represents the SOC value of a certain energy storage unit; P represents the active power on the AC side.

[0031] In one possible implementation, for energy storage units operating in the low-charge range, the discharge current is limited using the following method:

[0032]

[0033] In one embodiment, a half-bridge bidirectional DC / DC converter is used to control the output voltage of the energy storage device in order to limit the charging current and discharging current.

[0034] According to a second aspect of this application, a leveling control device for an energy storage power station considering SOC feedback is provided, the device comprising:

[0035] The calculation module is used to measure the terminal voltage of the energy storage unit and calculate the SOC value of the energy storage unit by combining the terminal voltage and the voltage characteristic curve.

[0036] The determination module is used to compare the SOC value with a threshold range and determine the power range in which the energy storage unit operates based on the comparison result; the threshold range represents the critical value for safe operation of the energy storage unit.

[0037] The limiting module is used to limit the charging and discharging power according to the energy range in which the energy storage unit operates, so as to achieve the balance of the SOC of different energy storage units.

[0038] The beneficial effects of this invention are as follows:

[0039] By utilizing the technical solution of this application, charging and discharging power is limited according to the energy range in which the energy storage unit operates, thereby achieving a balance of the SOC of different energy storage units and avoiding overcharging and over-discharging.

[0040] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0041] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which:

[0042] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0043] Figure 1 This illustration shows the implementation flow of the equalization control method for an energy storage power station considering SOC feedback in an embodiment of this application. Figure 1 ;

[0044] Figure 2 This illustration shows the implementation flow of the equalization control method for an energy storage power station considering SOC feedback in an embodiment of this application. Figure 2 ;

[0045] Figure 3 A block diagram of a half-bridge bidirectional DC / DC converter in an embodiment of this application is shown.

[0046] Figure 4 This paper shows a schematic diagram of the balancing control device of an energy storage power station considering SOC feedback according to an embodiment of this application.

[0047] Figure 5 A schematic diagram of the composition structure of the electronic device in an embodiment of this application is shown. Detailed Implementation

[0048] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0051] In the following description, the terms "first" and "second" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0053] It should be understood that in the various embodiments of this application, the sequence number of each implementation process 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 this application.

[0054] Figure 1 This illustration shows the implementation flow of the equalization control method for an energy storage power station considering SOC feedback in an embodiment of this application. Figure 1 .like Figure 1 As shown, the method includes:

[0055] S(Step)101: Measure the terminal voltage of the energy storage unit, and calculate the SOC value of the energy storage unit by combining the terminal voltage and the voltage characteristic curve;

[0056] In practical engineering applications, the storage capacity and operating voltage of a single energy storage unit are often relatively low. Therefore, large-capacity energy storage power stations must contain multiple energy storage units connected in series or parallel. During the operation of the energy storage power station, the State of Charge (SOC) of all energy storage units needs to be monitored in real time.

[0057] In some embodiments, the energy storage unit includes multiple units, and the calculation of the SOC value of the energy storage unit by combining the terminal voltage and voltage characteristic curve includes:

[0058] Determine the voltage characteristic curve for each energy storage unit;

[0059] Based on the voltage characteristic curve and the terminal voltage, the SOC value of the energy storage unit at the corresponding time is obtained.

[0060] If we disregard the impact of temperature variations and lifespan on the output characteristics of energy storage units, each unit possesses a fixed charge-discharge curve, i.e., the relationship between State of Charge (SOC) and terminal voltage. This curve can be obtained through simple charge-discharge experiments or by approximating the relationship using function fitting. Therefore, during the operation of an energy storage power station, by measuring the terminal voltage of the energy storage unit and then using the known charge-discharge curve, the current SOC value of that unit can be determined.

[0061] S102: Compare the SOC value with the threshold range, and determine the power range in which the energy storage unit operates based on the comparison result; the threshold range represents the critical value for safe operation of the energy storage unit.

[0062] The threshold range includes: the maximum critical value soc for safe operation of a single energy storage unit. max The minimum critical value (SOC) for safe operation of a single energy storage unit min The highest critical value (SOC) for unrestricted operation of a single energy storage unit. high The minimum critical value of SOC for unrestricted operation of a single energy storage unit. low ;

[0063] Among them, the highest critical value of SOC for unrestricted operation of a single energy storage unit. high The SOC value is greater than the maximum critical value for safe operation of a single energy storage unit. max The minimum critical value (SOC) for safe operation of a single energy storage unit min Less than the minimum critical value of SOC for unrestricted operation of a single energy storage unit low .

[0064] In some embodiments, comparing the SOC value with a threshold range and determining the energy range in which the energy storage unit operates based on the comparison result includes:

[0065] When the SOC value is greater than soc max At this time, the energy storage unit operates in the deep charging range;

[0066] When the SOC value is less than soc min At that time, the energy storage unit operates in the deep discharge range;

[0067] When the SOC value is greater than soc high And the SOC value is less than soc max hour,

[0068] When the SOC value is greater than soc min And the SOC value is less than soc low At that time, the energy storage unit operates in the low-power range;

[0069] When the SOC value is greater than soc low And the SOC value is less than soc high At that time, the energy storage unit operates in the equilibrium range.

[0070] S103: Based on the operating power range of the energy storage unit, the charging and discharging power is limited accordingly to achieve a balance of SOC for different energy storage units.

[0071] In some embodiments, charging the energy storage unit is prohibited when the energy storage unit is operating in the deep charging range;

[0072] When the energy storage unit is operating in the deep discharge range, the energy storage unit is prohibited from continuing to discharge;

[0073] When the energy storage unit operates in the high-capacity range, the charging power of the energy storage unit is limited by the control system.

[0074] When the energy storage unit operates in the low-power range, the discharge power of the energy storage unit is limited by the control system.

[0075] When the energy storage unit operates in the equilibrium range, the charging and discharging power of the energy storage unit is not limited by the control system.

[0076] soc max and soc min This represents the critical value for the safe operation of a single energy storage unit. When the SOC is greater than the soc max When the SOC is less than the SOC value, the energy storage unit is in the deep charging range, during which time the energy storage unit cannot be charged; min At this time, the energy storage unit is operating in the deep discharge range, and it should not be allowed to continue discharging; SOC high and soc low This represents the critical value for unrestricted operation of a single energy storage unit. Under the premise of ensuring the safe operation of the energy storage unit, when the State of Charge (SOC) is greater than the State of Charge (SOC) value... high When the energy storage unit operates in the high-capacity range, its charging power is limited by the control system: when the SOC is less than the SOC... low When the energy storage unit operates in the low-charge range, its discharge power is limited by the control system: when the state of charge (SOC) is greater than the state of charge (SOC)... low And smaller than SOC high At this time, the energy storage unit operates in the equilibrium range, and its charging and discharging power is not limited by the control system. For example, SOC max It is 0.8, socmin It is 0.2, soc high Take 0.7, soc low Take 0.3.

[0077] In some embodiments, charging and discharging power limits are applied according to the energy range in which the energy storage unit operates, including:

[0078] For energy storage units operating in the high-capacity range, the charging current is limited to limit the charging power;

[0079] For energy storage units operating in the low-power range, the discharge current is limited to restrict the discharge power.

[0080] like Figure 2 As shown, P battery P represents the total power output of all energy storage units on the DC side of the energy storage power station. battery A value greater than 0 indicates that power flows from the DC side to the AC side, at which point the energy storage power station provides necessary support to the grid; P battery A value less than 0 indicates that power flows from the AC side to the DC side, at which point the grid charges the energy storage unit.

[0081] It should be noted that P battery The active power P on the AC side is not equal to the reactive power P on the AC side because the phases of the output voltage and current on the AC side are not necessarily the same, and reactive power may flow between the energy storage power station and the AC grid. Furthermore, the impedance at the output of the three-phase inverter and the impedance in the DC / DC conversion circuit on the DC side also contribute to power loss. From a charging and discharging perspective, P can be... battery and P The relationship can be understood as power transmission efficiency, when P battery When the value is greater than 0, the formula is as follows:

[0082]

[0083] Where η is the power transmission efficiency, approximately 1 / 2. 90 %.

[0084] This application achieves charge / discharge power limitation by setting a limiter on the outer loop PI regulator of the DC-side voltage. When the energy storage unit operates in the linear region, its terminal voltage changes very slowly with the state of charge (SOC), therefore the terminal voltage can be approximated as a constant value U. DC Assume that the current output of a certain energy storage unit is I. DC The power calculation formula is as follows:

[0085] P battery =U DC I DC

[0086] When the voltage at the energy storage unit terminals remains approximately constant, the charging and discharging power of the energy storage unit can be limited by restricting the output current. A DC / DC dual closed-loop control has already been designed on the DC side. The output of the voltage outer loop PI regulator serves as the reference value for the energy storage unit's output current. Under conditions of good system tracking performance, limiting the output amplitude of the voltage outer loop PI regulator can limit the magnitude of the energy storage unit's output current, thereby limiting its charging and discharging power. For energy storage units operating in the high-capacity range, the charging current limiting formula is as follows:

[0087]

[0088] Where n represents the total number of energy storage units on the DC side of the energy storage power station; I sat (x) represents the output current limiting value of a certain energy storage unit; U DC (x) represents the terminal voltage of a certain energy storage unit; soc(x) represents the SOC value of a certain energy storage unit; P represents the active power on the AC side.

[0089] For energy storage units operating in the low-power range, the following methods are used to limit the discharge current.

[0090]

[0091] In some embodiments, a half-bridge bidirectional DC / DC converter is used to control the output voltage of the energy storage element in order to limit the charging current and discharging current.

[0092] like Figure 3 The diagram shown is a schematic of a half-bridge bidirectional DC / DC converter. Figure 3 In this diagram, DC represents the ideal voltage source equivalent to the energy storage element, R represents the equivalent internal voltage of the energy storage element, L is the filter reactance of the DC / DC converter, Udc is the voltage of the DC-side capacitor, and Rdc is the equivalent load resistance of the energy storage converter circuit. The upper and lower bridge arms of the DC / DC converter are a set of identical high-power sub-switches with complementary control. When the power switch on the upper side of the bridge arm is turned on, the filter reactance and the DC-side capacitor are connected, supplying power to the load while simultaneously energizing the capacitor. When the power switch on the lower side of the bridge arm is turned on, the filter reactance and the energy storage element are connected. At this time, the filter reactance is charged, and the DC-side capacitor supplies power to the load using its stored energy.

[0093] The design of the bidirectional DC / DC converter on the DC side of the energy storage power station provided in this application enables bidirectional power flow between the energy storage unit on the DC side and the power grid on the AC side, which helps to achieve SOC equalization control of the energy storage power station.

[0094] It is understandable that when the charge-discharge curves of various energy storage units are similar, if the charge-discharge current of the energy storage units is not limited, the input and output power of each energy storage unit during operation will also be similar, and will not be affected by differences in capacity and SOC. In this case, the difference in SOC among the energy storage units is also fixed, so it is impossible to achieve relative balance during operation. However, if the output of the voltage outer loop PI regulator is limited, the charge-discharge power of a specific energy storage unit can be limited. Assuming that a sufficient number of energy storage units in the energy storage power station operate in the equilibrium range, the output power of the AC side of the energy storage power station will not decrease due to the limited output power of individual energy storage units, because the energy storage units operating in the equilibrium range will actively increase their output to maintain system stability. Therefore, under the condition that the output power of individual energy storage units is limited, regardless of the direction of power flow, the charge-discharge power of energy storage units operating in the equilibrium range is relatively higher. When power flows from the DC side to the AC side, the control system can achieve relative SOC balance by limiting the discharge power of the energy storage unit operating in the low charge range; when power flows from the AC side to the DC side, the control system can achieve relative SOC balance by limiting the charging power of the energy storage unit operating in the high charge range.

[0095] This application enables energy storage units with different SOCs to be protected during system operation, avoiding overcharging and over-discharging, and achieving relative balance of SOCs among different energy storage units.

[0096] like Figure 4 As shown, this application provides a balancing control device for an energy storage power station considering SOC feedback, the device comprising:

[0097] The calculation module 401 is used to measure the terminal voltage of the energy storage unit and calculate the SOC value of the energy storage unit by combining the terminal voltage and the voltage characteristic curve.

[0098] The determination module 402 is used to compare the SOC value with a threshold range and determine the power range in which the energy storage unit operates based on the comparison result; the threshold range represents the critical value for safe operation of the energy storage unit.

[0099] The limiting module 403 is used to limit the charging and discharging power according to the energy range in which the energy storage unit operates, so as to achieve the balance of the SOC of different energy storage units.

[0100] The working principle of the energy storage power station balancing control device considering SOC feedback provided in this application is as follows: the calculation module 401 measures the terminal voltage of the energy storage unit and calculates the SOC value of the energy storage unit by combining the terminal voltage and voltage characteristic curve; the determination module 402 compares the SOC value with a threshold range and determines the power range in which the energy storage unit operates based on the comparison result; the threshold range represents the critical value for safe operation of the energy storage unit; and the limiting module 403 limits the charging and discharging power accordingly based on the power range in which the energy storage unit operates, so as to achieve SOC balancing of different energy storage units.

[0101] In other embodiments, this application may also provide an electronic device, including:

[0102] At least one processor; and

[0103] A memory communicatively connected to the at least one processor; wherein,

[0104] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method described in this application.

[0105] In other embodiments, this application may also provide a non-transitory computer-readable storage medium storing computer instructions for causing the computer to perform the methods described in this application.

[0106] like Figure 5 As shown, device 500 includes a computing unit 501, which can perform various appropriate actions and processes based on a computer program stored in read-only memory (ROM) 502 or a computer program loaded from storage unit 508 into random access memory (RAM) 503. RAM 503 may also store various programs and data required for the operation of device 500. The computing unit 501, ROM 502, and RAM 503 are interconnected via bus 504. Input / output (I / O) interface 505 is also connected to bus 504.

[0107] Multiple components in device 500 are connected to I / O interface 505, including: input unit 506, such as keyboard, mouse, etc.; output unit 507, such as various types of monitors, speakers, etc.; storage unit 508, such as disk, optical disk, etc.; and communication unit 509, such as network card, modem, wireless transceiver, etc. Communication unit 509 allows device 500 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0108] The computing unit 501 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 501 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 501 performs the various methods and processes described above, such as the equalization control method for an energy storage power station considering SOC feedback. For example, in some embodiments, the equalization control method for an energy storage power station considering SOC feedback can be implemented as a computer software program tangibly contained in a machine-readable medium, such as storage unit 508. In some embodiments, part or all of the computer program can be loaded and / or installed on device 500 via ROM 502 and / or communication unit 509. When the computer program is loaded into RAM 503 and executed by the computing unit 501, one or more steps of the equalization control method for an energy storage power station considering SOC feedback described above can be performed. Alternatively, in other embodiments, computing unit 501 may be configured by any other suitable means (e.g., by means of firmware) to perform a leveling control method for an energy storage power station that takes into account SOC feedback.

[0109] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0110] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0111] In the context of this application, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0112] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0113] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with embodiments of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0114] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0115] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. Considering the equilibrium control method of an energy storage power station with SOC feedback, Its features are, The method includes: Measure the terminal voltage of the energy storage unit, and calculate the SOC value of the energy storage unit by combining the terminal voltage and the voltage characteristic curve; The SOC value is compared with a threshold range, and the energy range in which the energy storage unit operates is determined based on the comparison result; the threshold range represents the critical value for the safe operation of the energy storage unit. The charging and discharging power is limited according to the energy range in which the energy storage unit operates, so as to achieve a balance of the SOC of different energy storage units; The threshold range includes: the maximum critical value for safe operation of a single energy storage unit. Minimum critical value for safe operation of a single energy storage unit The highest critical value for unrestricted operation of a single energy storage unit Minimum critical value for unrestricted operation of a single energy storage unit ; Among them, the highest critical value for unrestricted operation of a single energy storage unit. Greater than the maximum critical value for safe operation of a single energy storage unit The minimum critical value for safe operation of a single energy storage unit Less than the minimum critical value for unrestricted operation of a single energy storage unit ; The step of comparing the SOC value with a threshold range and determining the energy range in which the energy storage unit operates based on the comparison result includes: When the SOC value is greater than At this time, the energy storage unit operates in the deep charging range; When the SOC value is less than At that time, the energy storage unit operates in the deep discharge range; When the SOC value is greater than And the SOC value is less than hour, When the SOC value is greater than And the SOC value is less than At that time, the energy storage unit operates in the low-power range; When the SOC value is greater than And the SOC value is less than At that time, the energy storage unit operates in the equilibrium range; The charging and discharging power is limited according to the operating range of the energy storage unit, including: For energy storage units operating in the high-capacity range, the charging current is limited to limit the charging power; For energy storage units operating in the low-power range, the discharge current is limited to limit the discharge power. For energy storage units operating in the high-capacity range, the charging current is limited using the following methods. ； Where n represents the total number of energy storage units on the DC side of the energy storage power station; This represents the output current limit value of a specific energy storage unit. Represents the terminal voltage of a specific energy storage unit; SOC represents the SOC value of a specific energy storage unit; P represents the active power on the AC side. For energy storage units operating in the low-capacity range, the following methods are used to limit the discharge current. 。 2. The equalization control method for an energy storage power station considering SOC feedback as described in claim 1, Its features are, The energy storage unit comprises multiple units, and the calculation of the SOC value of the energy storage unit by combining the terminal voltage and voltage characteristic curve includes: Determine the voltage characteristic curve for each energy storage unit; Based on the voltage characteristic curve and the terminal voltage, the SOC value of the energy storage unit at the corresponding time is obtained.

3. The equalization control method for an energy storage power station considering SOC feedback as described in claim 1, Its features are, Charging the energy storage unit is prohibited when it is operating in the deep charging range. When the energy storage unit is operating in the deep discharge range, the energy storage unit is prohibited from continuing to discharge; When the energy storage unit operates in the high-capacity range, the charging power of the energy storage unit is limited by the control system. When the energy storage unit operates in the low-power range, the discharge power of the energy storage unit is limited by the control system. When the energy storage unit operates in the equilibrium range, the charging and discharging power of the energy storage unit is not limited by the control system.

4. The equalization control method for an energy storage power station considering SOC feedback as described in claim 1, Its features are, A half-bridge bidirectional DC / DC converter is used to control the output voltage of the energy storage components in order to limit the charging current and discharging current.

5. A balancing control device for an energy storage power station considering SOC feedback, characterized in that, The method described by any one of claims 1-4, include: The calculation module is used to measure the terminal voltage of the energy storage unit and calculate the SOC value of the energy storage unit by combining the terminal voltage and the voltage characteristic curve. The determination module is used to compare the SOC value with a threshold range and determine the power range in which the energy storage unit operates based on the comparison result; the threshold range represents the critical value for safe operation of the energy storage unit. The limiting module is used to limit the charging and discharging power according to the energy range in which the energy storage unit operates, so as to achieve the balance of the SOC of different energy storage units.

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