Balanced control method and device for energy storage power station considering SOC feedback

Abstract

The invention discloses an energy storage power station equalization control method and device considering SOC feedback, and the method comprises the steps: measuring the terminal voltage of an energy storage unit, and calculating the SOC value of the energy storage unit through combining the terminal voltage with a voltage characteristic curve; comparing the SOC value with a threshold range, and determining a working electric quantity interval of the energy storage unit according to a comparison result; the threshold range represents a critical value of safe work of the energy storage unit; and carrying out corresponding charging and discharging power limitation according to the working electric quantity interval of the energy storage unit so as to realize SOC balance of different energy storage units. According to the invention, the charging and discharging power is limited according to the working electric quantity interval of the energy storage unit, so that the SOC balance of different energy storage units is realized, and overcharging and overdischarging are avoided.

Description

Technical Field

[0001] The present application relates to the field of power systems, and in particular to a method and device for balancing control of an energy storage power station taking SOC feedback into consideration, which is specifically used for balancing control of an energy storage power station. Background Art

[0002] In the existing energy storage power station control technology, the front stage of the energy storage power station must output a certain voltage level to meet the needs of the rear stage three-phase IGBT inverter. At present, most energy storage power stations use batteries as the basic energy storage unit;

[0003] When the 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 working in the linear region will not change significantly. However, as the discharge time increases, the battery's SOC will continue to decrease, causing the battery's output voltage to continue to decrease, resulting in lower quality of the power output by the energy storage power station. Summary of the invention

[0004] The present invention discloses a balanced control method, device, equipment and storage medium of an energy storage power station considering SOC feedback, so as to at least solve the above technical problems existing in the prior art.

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

[0006] Measuring the terminal voltage of the energy storage unit, and calculating the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve;

[0007] Comparing the SOC value with a threshold range, and determining the power range of the energy storage unit according to the comparison result; the threshold range represents the critical value of the energy storage unit for safe operation;

[0008] The corresponding charging and discharging power limits are imposed according to the working power range of the energy storage unit to achieve the balance of SOC of different energy storage units.

[0009] In one possible implementation manner, the energy storage unit includes a plurality of units, and the calculating the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve includes:

[0010] Determine the voltage characteristic curve corresponding to 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 moment is obtained.

[0012] In one embodiment, the threshold range includes: the maximum critical value soc of a single energy storage unit for safe operation max, the minimum critical value soc for safe operation of a single energy storage unit min , the highest critical value soc of a single energy storage unit without restriction high , the minimum critical value soc for unrestricted operation of a single energy storage unit low ;

[0013] Among them, the highest critical value soc of a single energy storage unit without restriction is high Greater than 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 Less than the minimum critical value soc of a single energy storage unit without restriction low .

[0014] In one possible implementation manner, comparing the SOC value with a threshold range and determining the power range of the energy storage unit according to the comparison result includes:

[0015] When the SOC value is greater than soc max When , the energy storage unit works in the deep charging range;

[0016] When the SOC value is less than soc min When , the energy storage unit works 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 When , the energy storage unit works in the low power range;

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

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

[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 a high power range, the energy storage unit operates in a high power range; the charging power of the energy storage unit is limited by the control system;

[0023] When the energy storage unit operates in a 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 corresponding charging and discharging power limitation is performed according to the power range of the energy storage unit, including:

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

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

[0028] In one possible implementation, for an energy storage unit operating in a high power range, the charging current is limited in the following manner:

[0029]

[0030] Where n represents the total number of energy storage units on the DC side of the energy storage power station; sat (x) represents the output current limit 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 an energy storage unit operating in a low power range, the discharge current is limited in the following manner:

[0032]

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

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

[0035] A calculation module, used to measure the terminal voltage of the energy storage unit, and calculate the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve;

[0036] A determination module, used to compare the SOC value with a threshold range, and determine the power range of the energy storage unit according to the comparison result; the threshold range represents the critical value of the safe operation of the energy storage unit;

[0037] The limiting module is used to perform corresponding charging and discharging power limits according to the power range of the energy storage unit to achieve SOC balance of different energy storage units.

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

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

[0040] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become readily understood. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, wherein:

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

[0043] Figure 1 The schematic diagram shows the implementation process of the balanced control method of the energy storage power station considering SOC feedback in the embodiment of the present application. Figure 1 ;

[0044] Figure 2 The schematic diagram shows the implementation process of the balanced control method of the energy storage power station considering SOC feedback in the embodiment of the present application. Figure 2 ;

[0045] Figure 3 The structure block diagram of the half-bridge bidirectional DC / DC converter in the embodiment of the present application is shown;

[0046] Figure 4 A schematic diagram of the structure of a balancing control device of an energy storage power station considering SOC feedback in an embodiment of the present application is shown;

[0047] Figure 5 A schematic diagram of the structure of an electronic device in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0048] In order to make the purpose, features, and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0049] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of this application.

[0050] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it can be 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\second" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that "first\second" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present 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 those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0053] It should be understood that in the various embodiments of the present application, the size of the serial number of each implementation process does not 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 embodiments of the present application.

[0054] Figure 1 The schematic diagram shows the implementation process of the balanced control method of the energy storage power station considering SOC feedback in the embodiment of the present application. Figure 1 .like Figure 1 As shown, the method includes:

[0055] S (Step) 101: measuring the terminal voltage of the energy storage unit, and calculating the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve;

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

[0057] In some embodiments, the energy storage unit includes a plurality of energy storage units, and the step of calculating the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve includes:

[0058] Determine the voltage characteristic curve corresponding to 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 moment is obtained.

[0060] If we do not consider the impact of temperature changes and service life on the output characteristics of the energy storage unit, each energy storage unit has a fixed charge and discharge curve, that is, the relationship between SOC and terminal voltage. This curve can be obtained through simple charge and discharge experimental measurements, or the approximate functional relationship between the two can be obtained through function fitting. Therefore, during the operation of the energy storage power station, the terminal voltage of the energy storage unit is measured, and then the SOC value of the energy storage unit at the current moment can be obtained by using the known charge and discharge curve of the energy storage unit.

[0061] S102: Compare the SOC value with a threshold range, and determine the power range of the energy storage unit according to the comparison result; the threshold range represents the critical value of the energy storage unit for safe operation;

[0062] The threshold range includes: the maximum critical value soc of a single energy storage unit for safe operation max , the minimum critical value soc for safe operation of a single energy storage unit min , the highest critical value soc of a single energy storage unit without restriction high , the minimum critical value soc for unrestricted operation of a single energy storage unit low ;

[0063] Among them, the highest critical value soc of a single energy storage unit without restriction is high Greater than 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 Less than the minimum critical value soc of a single energy storage unit without restriction low .

[0064] In some embodiments, comparing the SOC value with a threshold range and determining the power range of the energy storage unit according to the comparison result includes:

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

[0066] When the SOC value is less than soc min When , the energy storage unit works 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 When , the energy storage unit works in the low power range;

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

[0070] S103: Perform corresponding charge and discharge power limits according to the power range of the energy storage unit to achieve SOC balance of different energy storage units.

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

[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 a high power range, the energy storage unit operates in a high power range; the charging power of the energy storage unit is limited by the control system;

[0074] When the energy storage unit operates in a 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 Represents the critical value of safe operation of a single energy storage unit. When SOC is greater than soc max When SOC is less than soc min When the energy storage unit is working in the deep discharge range, the energy storage unit cannot continue to discharge; soc high and soc low Represents the critical value of a single energy storage unit without restriction. Under the premise of ensuring the safe operation of the energy storage unit, when SOC is greater than soc high When the SOC is less than soc low When the SOC is greater than soc low And less than soc high When the energy storage unit works in the equilibrium range, its charging and discharging power is not limited by the control system. max is 0.8, socmin is 0.2, soc high Take 0.7, soc low Take 0.3.

[0077] In some embodiments, the corresponding charging and discharging power limitation is performed according to the power range of the energy storage unit, including:

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

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

[0080] like Figure 2 As shown, P battery Represents the total power output of each energy storage unit on the DC side of the energy storage station, P battery Greater than 0 means that power flows from the DC side to the AC side. At this time, the energy storage power station provides necessary support for the power grid. battery Less than 0 means that power flows from the AC side to the DC side, and the grid charges the energy storage unit.

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

[0082]

[0083] Here, η is the power transfer efficiency, which is approximately 90%.

[0084] The present application realizes the charge and discharge power limitation by setting a limiter for the DC side voltage outer loop PI regulator. When the energy storage unit works in the linear region, its terminal voltage changes very slowly with the SOC, so the terminal voltage can be approximately regarded as a constant value U DC , assuming that the current value output by 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 end of the energy storage unit remains approximately unchanged, the charging and discharging power of the energy storage unit can be limited by limiting the output current. The DC / DC dual closed-loop control on the DC side has been designed in the previous article. The output of the voltage outer loop PI regulator is the reference value of the output current of the energy storage unit. Under the condition of good system following performance, limiting the output amplitude of the voltage outer loop PI regulator can limit the output current of the energy storage unit, thereby limiting its charging and discharging power. For energy storage units operating in the high power range, the charging current limit 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; sat (x) represents the output current limit 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] Among them, for the energy storage unit working in the low power range, the discharge current is limited in the following way:

[0090]

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

[0092] like Figure 3 As shown in the figure, it is a schematic diagram of the structure of a half-bridge bidirectional DC / DC converter. Figure 3 In the figure, DC represents the ideal voltage source equivalent to the energy storage element, R represents the equivalent internal resistance of the energy storage element, L is the filter reactance of the DC / DC converter, and U dc is the voltage of the DC side capacitor, R dc 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 that use complementary control. When the power switch tube on the upper side of the bridge arm is turned on, the filter reactance is connected to the DC side capacitor, and the capacitor 3 is charged while supplying power to the load: when the power switch tube on the lower side of the bridge arm is turned on, the filter reactance is connected to the energy storage element. At this time, the filter reactance is charged, and the DC side capacitor relies on its own stored energy to supply power to the load.

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

[0094] It is understandable that when the charge and discharge curves of each energy storage unit are similar, if the charge and discharge current of the energy storage unit is not limited, then the input and output power of each energy storage unit during operation is also close, and will not be affected by the different capacity and SOC. At this time, the difference in SOC of each energy storage unit is also fixed, so it is impossible to achieve relative balance during operation. If the output of the voltage outer loop PI regulator is limited, the charge and discharge power of a specific energy storage unit can be limited. Assuming that there are a sufficient number of energy storage units in the energy storage power station working in the equilibrium range, at this time, the output power on the AC side of the energy storage power station will not be reduced due to the limited output power of individual energy storage units, because the energy storage units working in the equilibrium range will actively increase the output to maintain the stability of the system. Therefore, under the condition where the output power of individual energy storage units is limited, regardless of the direction of power flow, the charge and discharge power of the energy storage units working 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 power 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 power range.

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

[0096] like Figure 4 As shown, the present application provides a balanced control device for an energy storage power station taking into account SOC feedback, the device comprising:

[0097] A 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 in combination with the terminal voltage and the voltage characteristic curve;

[0098] A determination module 402 is used to compare the SOC value with a threshold range, and determine the power range of the energy storage unit according to the comparison result; the threshold range represents the critical value of the energy storage unit for safe operation;

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

[0100] The working principle of the balancing control device of the energy storage power station considering SOC feedback provided in the present application is that the calculation module 401 measures the terminal voltage of the energy storage unit, and calculates the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve; the determination module 402 compares the SOC value with the threshold range, and determines the working power range of the energy storage unit according to the comparison result; the threshold range represents the critical value for the safe operation of the energy storage unit; the limiting module 403 performs corresponding charging and discharging power limitations according to the working power range of the energy storage unit to achieve SOC balancing of different energy storage units.

[0101] In other embodiments, the present 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, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method described in the present application.

[0105] In other embodiments, the present application may also provide a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable the computer to execute the method described in the present application.

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

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

[0108] The computing unit 501 may be a variety of general and / or special 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 dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 501 performs the various methods and processes described above, such as a balanced control method for an energy storage power station considering SOC feedback. For example, in some embodiments, the balanced control method for an energy storage power station considering SOC feedback may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 508. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 500 via the ROM 502 and / or the communication unit 509. When the computer program is loaded into the RAM 503 and executed by the computing unit 501, one or more steps of the balanced control method for an energy storage power station considering SOC feedback described above may be performed. Alternatively, in other embodiments, the computing unit 501 may be configured in any other appropriate manner (eg, by means of firmware) to execute a balancing control method for an energy storage power station taking SOC feedback into consideration.

[0109] Various implementations 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 chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0110] The program code for implementing the method of the present application can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, implements the functions / operations specified in the flow chart and / or block diagram. The program code can be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0111] In the context of the present application, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, 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 (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the 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 acoustic input, voice input, or tactile input).

[0113] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0114] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship with each other. The server may be a cloud server, a server of a distributed system, or a server combined with a blockchain.

[0115] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. Balanced control method of energy storage power station considering SOC feedback, It is characterized in that The method comprises: Measuring the terminal voltage of the energy storage unit, and calculating the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve; Comparing the SOC value with a threshold range, and determining the power range of the energy storage unit according to the comparison result; the threshold range represents the critical value of the energy storage unit for safe operation; The corresponding charging and discharging power limits are imposed according to the working power range of the energy storage unit to achieve the balance of SOC of different energy storage units.

2. The balanced control method of the energy storage power station considering SOC feedback according to claim 1, It is characterized in that The energy storage unit includes a plurality of units, and the calculating the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve includes: Determine the voltage characteristic curve corresponding to 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 moment is obtained.

3. The balanced control method of the energy storage power station considering SOC feedback according to claim 1, It is characterized in that The threshold range includes: the maximum critical value soc of a single energy storage unit for safe operation max , the minimum critical value soc for safe operation of a single energy storage unit min , the highest critical value of a single energy storage unit without restriction chigh , the minimum critical value soc for unrestricted operation of a single energy storage unit low ; Among them, the highest critical value soc of a single energy storage unit without restriction is high Greater than 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 Less than the minimum critical value soc of a single energy storage unit without restriction low .

4. The balanced control method of the energy storage power station considering SOC feedback according to claim 3, It is characterized in that The step of comparing the SOC value with a threshold range and determining the power range of the energy storage unit according to the comparison result includes: When the SOC value is greater than soc max When , the energy storage unit works in the deep charging range; When the SOC value is less than soc min When , the energy storage unit works in the deep discharge range; When the SOC value is greater than soc high And the SOC value is less than soc max hour, When the SOC value is greater than soc min And the SOC value is less than soc low When , the energy storage unit works in the low power range; When the SOC value is greater than soc low And the SOC value is less than soc high When , the energy storage unit works in the equilibrium range.

5. The balanced control method of the energy storage power station considering SOC feedback according to claim 4, It is characterized in that When the energy storage unit is operating in the deep charging range, charging of the energy storage unit is prohibited; 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 a high power range, the energy storage unit operates in a high power range; the charging power of the energy storage unit is limited by the control system; When the energy storage unit operates in a 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.

6. The balanced control method of the energy storage power station considering SOC feedback according to claim 1, It is characterized in that According to the working power range of the energy storage unit, the corresponding charging and discharging power limits are implemented, including: For energy storage units operating in a high power range, the charging current is limited to limit the charging power; For energy storage units operating in a low power range, the discharge current is limited to limit the discharge power.

7. The balanced control method of the energy storage power station considering SOC feedback according to claim 6, It is characterized in that For energy storage units operating in the high power range, the charging current is limited in the following ways: Where n represents the total number of energy storage units on the DC side of the energy storage power station; sat (x) represents the output current limit 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.

8. The balanced control method of the energy storage power station considering SOC feedback according to claim 2, It is characterized in that For energy storage units operating in a low power range, the following methods are used to limit the discharge current:

9. The balanced control method of the energy storage power station considering SOC feedback according to claim 6, It is characterized in that A half-bridge bidirectional DC / DC converter is used to control the output voltage of the energy storage element to limit the charging current and the discharging current.

10. A balanced control device for an energy storage power station considering SOC feedback, It is characterized in that include: A calculation module, used to measure the terminal voltage of the energy storage unit, and calculate the SOC value of the energy storage unit in combination with the terminal voltage and the voltage characteristic curve; A determination module, used to compare the SOC value with a threshold range, and determine the power range of the energy storage unit according to the comparison result; the threshold range represents the critical value of the safe operation of the energy storage unit; The limiting module is used to perform corresponding charging and discharging power limits according to the power range of the energy storage unit to achieve SOC balance of different energy storage units.

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