Control system for energy storage system, control method therefor, and energy storage system

Abstract

An energy storage system (100), a control system (200) and a control method (300) of the energy storage system (100), wherein the energy storage system (100) includes a converter valve (110) and an energy storage valve (120) connected to the DC side of the converter valve (110), and the control system (200) includes a cooperative control subsystem (210), a converter valve control subsystem (220) and an energy storage valve control subsystem (230). The cooperative control subsystem (210) is used to send commands to control the operations of the converter valve control subsystem (220) and the energy storage valve control subsystem (230). The converter valve control subsystem (220) is used to control the operation of the converter valve (110) according to the commands of the cooperative control subsystem (210). The energy storage valve control subsystem (230) is used to control the operation of the energy storage valve (120) according to the commands of the cooperative control subsystem (210). The control system (200) of the energy storage system (100) can achieve the cooperative control of the converter valve (110) and the energy storage valve (120).

Description

Technical Field

[0006]

[0001] This application relates to the field of energy storage technology for power systems, and particularly to a control system for an energy storage system, its control method, and an energy storage system.

Background Art

[0002] In the field of energy storage technology for power systems, new energy storage technologies have advantages such as integrating converter valves and energy storage valves, high modularity, low transmission losses, good economic effects, and high operation reliability.

[0003] Currently, the control structure of new energy storage systems has not been studied.

Summary of the Invention

[0004] In view of this, embodiments of this application provide a control system for an energy storage system, its control method, and an energy storage system that can achieve coordinated control between a converter valve and an energy storage valve.

[0005] In a first aspect, a control system for an energy storage system is provided. The energy storage system includes a converter valve and an energy storage valve connected to the DC side of the converter valve. The control system includes a coordinated control subsystem, a converter valve control subsystem, and an energy storage valve control subsystem. The coordinated control subsystem is used to send commands to control the operations of the converter valve control subsystem and the energy storage valve control subsystem. The converter valve control subsystem is used to control the operation of the converter valve according to the commands of the coordinated control subsystem. The energy storage valve control subsystem is used to control the operation of the energy storage valve according to the commands of the coordinated control subsystem.

[0006] In this embodiment, the cooperative control subsystem controls the operation of the converter valve control subsystem and the energy storage valve control subsystem, thereby enabling coordinated control of the converter valve and the energy storage valve.

[0007] In a possible embodiment, the converter valve includes N first power modules, the converter valve control subsystem includes a converter valve control unit and N first power control units, where N is a positive integer, the converter valve control unit is used to generate K first control commands for the N first power modules in accordance with the commands of the coordinate control subsystem, where K is a positive integer less than or equal to N, and the N first power control units are used to control the switching on or switching off of the N first power modules, respectively, in accordance with the K first control commands.

[0008] In this embodiment, a converter valve control unit and N first power modules are provided for N first power modules among the converter valves, and the converter valve control unit communicates with the cooperative control subsystem as a higher-level control unit for the N first power control units. In other words, the converter valve control subsystem adopts a hierarchical design and modular design, which facilitates expansion and integration.

[0009] In possible embodiments, each of the N first power control units is also used to upload state information of the corresponding first power module to the converter valve control unit.

[0010] In this embodiment, the first power control unit uploads the status information of the first power module to the converter valve control unit, which makes it easier for the converter valve control unit to grasp the status of each first power module in a timely manner, thereby ensuring the reliability of system control.

[0011] In possible embodiments, the converter valve control unit is also used to upload the valve control status information of the converter valve to a cooperative control subsystem.

[0012] In this embodiment, the converter valve control unit uploads the valve control status information of the converter valve to the cooperative control subsystem, which makes it easier for the cooperative control subsystem to grasp the status of the converter valve in a timely manner, thereby enabling better coordinated control of the operation of the converter valve and the energy storage valve and ensuring the reliability of system control.

[0013] In possible embodiments, the energy storage valve comprises M energy storage modules, each of the M energy storage modules comprising a second power module and a battery module; the energy storage valve control subsystem comprises an energy storage valve control unit, M second power control units, and M battery control units, where M is a positive integer; the energy storage valve control unit is used to generate Q second control commands for the M second power modules in the M energy storage modules, in accordance with the commands of the coordinate control subsystem, where Q is a positive integer less than or equal to M; the M second power control units are used to control the switching on or off of the M second power modules, respectively, in accordance with the Q second control commands; and the M battery control units are used to control the charging and discharging of the M battery modules in the M energy storage modules, respectively.

[0014] In this embodiment, an energy storage valve control unit, M second power control units, and M battery control units are provided for M second power modules and M battery modules in the energy storage valve. The energy storage valve control unit communicates with the cooperative control subsystem as a higher-level control unit for the M second power control units. In other words, the energy storage valve control subsystem adopts a hierarchical and modular design, making expansion and integration easy. Furthermore, the converter valve and the energy storage valve are controlled separately, and the technology of the converter valve control subsystem is relatively mature. The energy storage valve control subsystem can be expanded and developed based on the converter valve control subsystem, making engineering feasibility easy.

[0015] In possible embodiments, the energy storage valve control unit is also used to generate P third control commands for the M battery modules in accordance with the commands of the cooperative control subsystem, where P is a positive integer less than or equal to M, and the M battery control units are used to charge and discharge each of the M battery modules in accordance with the P third control commands.

[0016] In this embodiment, the M battery control units may communicate directly with the energy storage valve control unit, making it easier for the second power control unit and the battery control unit to control the second power module and the battery module in parallel, thereby improving the control efficiency of the system.

[0017] In possible embodiments, each of the M battery control units is also used to upload the status information of the corresponding battery module to the energy storage valve control unit.

[0018] In this embodiment, the battery control unit uploads the status information of the corresponding battery module to the energy storage valve control unit, allowing the energy storage valve control unit to grasp the status of the battery module in a timely manner and perform appropriate control on the battery module, thereby ensuring the control reliability of the energy storage valve control subsystem.

[0019] In possible embodiments, the M second power control units are also used to generate R fourth control commands for the M battery modules, respectively, according to the Q second control commands, where R is a positive integer less than or equal to M, and the M battery control units are used to charge and discharge the M battery modules, respectively, according to the R fourth control commands.

[0020] In this embodiment, M battery control units are each controlled by M second power control units, thereby reducing the communication load on the energy storage valve control unit.

[0021] In possible embodiments, each of the M battery control units is also used to upload the status information of the corresponding battery module to the corresponding second power control unit.

[0022] In this embodiment, the battery control unit uploads the status information of the corresponding battery module to the second power control unit, which in turn provides timely feedback of the battery module's status to the energy storage valve control unit, enabling appropriate control of the battery module. This ensures the control reliability of the energy storage valve control subsystem.

[0023] In possible embodiments, the energy storage valve control unit is also used to upload valve control status information of the energy storage valve to the cooperative control subsystem.

[0024] In this embodiment, the energy storage valve control unit uploads the valve control state information of the energy storage valve to the cooperative control subsystem, making it easier for the cooperative control subsystem to timely grasp the state of the energy storage valve, better coordinate the operations of the converter valve and the energy storage valve, and ensure the reliability of system control.

[0025] In a possible embodiment, each of the M second power control units in the M second power control units is also used to upload the state information of the corresponding second power module to the energy storage valve control unit.

[0026] In this embodiment, by the second power control unit uploading the state information of the second power module to the energy storage valve control unit, it becomes easier for the energy storage valve control unit to timely grasp the state of each second power module, and the reliability of system control can be ensured.

[0027] In a possible embodiment, the second power control unit corresponding to the same energy storage module and the battery control unit communicate with each other.

[0028] In a possible embodiment, the energy storage valve control subsystem further includes a battery monitoring unit for acquiring the battery data of the M battery modules.

[0029] In a possible embodiment, M is a positive integer greater than 1, and the M battery control units are connected by daisy chain communication.

[0030] In a possible embodiment, the converter valve control subsystem includes a plurality of converter valve control units, and each converter valve control unit in the plurality of converter valve control units communicates with the N first power control units, and the plurality of converter valve control units communicate with each other.

[0031] In this embodiment, the converter valve control subsystem includes a plurality of converter valve control units, and the plurality of converter valve control units communicate with each other and all communicate with N first power control units, thereby meeting the requirements for the redundant design of the converter valve control subsystem and ensuring the control reliability of the converter valve control subsystem.

[0032] In a possible embodiment, the energy storage valve control subsystem includes a plurality of energy storage valve control units, and each energy storage valve control unit in the plurality of energy storage valve control units communicates with the M second power control units, and the plurality of energy storage valve control units communicate with each other.

[0033] In this embodiment, the energy storage valve control subsystem includes a plurality of energy storage valve control units, and the plurality of energy storage valve control units communicate with each other and all communicate with M second power control units, thereby meeting the requirements for the redundant design of the energy storage valve control subsystem and ensuring the control reliability of the energy storage valve control subsystem.

[0034] In a possible embodiment, the coordinated control subsystem includes a plurality of system control units, and each system control unit in the plurality of system control units communicates with the converter valve control subsystem and the energy storage valve control subsystem, and the plurality of system control units communicate with each other.

[0035] In this embodiment, the coordinated control subsystem includes a plurality of system control units, and the plurality of system control units communicate with each other and all communicate with the converter valve control subsystem and the energy storage valve control subsystem, thereby meeting the requirements for the redundant design of the coordinated control subsystem and ensuring the control reliability of the coordinated control subsystem.

[0036] In possible embodiments, the converter valve control subsystem is integrated into the converter valve, and the energy storage valve control subsystem is integrated into the energy storage valve.

[0037] In a second embodiment, an energy storage system is provided which includes a converter valve and an energy storage valve connected to the DC side of the converter valve, the energy storage system further including a control system according to the first embodiment and any possible embodiment thereof.

[0038] In a third embodiment, a method for controlling an energy storage system including a converter valve and an energy storage valve connected to the DC side of the converter valve is provided, the control method comprising transmitting a first command to a converter valve control subsystem for controlling the operation of the converter valve and a second command to an energy storage valve control subsystem for controlling the operation of the energy storage valve.

[0039] A fourth aspect provides a computer-readable storage medium that is used to store a computer program that causes a computer to execute a method according to the first aspect and any possible embodiment of the first aspect. [Brief explanation of the drawing]

[0040] To more clearly explain the technical concept of the embodiments of this application, the following is a brief description of the drawings to be used in the embodiments of this application. Clearly, the following drawings show only some embodiments of this application, and those skilled in the art can obtain further drawings based on these drawings without any creative effort.

[0041] [Figure 1] This shows a schematic diagram of a high-voltage DC direct-acting energy storage system applied to the embodiments of the present invention. [Figure 2] Figure 1 shows a schematic diagram of the VSC converter valve. [Figure 3] Figure 1 shows a schematic diagram of the DC energy storage valve. [Figure 4a] Figure 3 shows a schematic diagram of the energy storage module. [Figure 4b] Figure 3 shows another schematic diagram of the energy storage module. [Figure 5] This diagram shows a schematic structure of the control system according to an embodiment of the present invention. [Figure 6] Figure 5 shows a schematic diagram of the converter valve control subsystem in the control system. [Figure 7] Figure 5 shows a schematic diagram of the energy storage valve control subsystem in the control system. [Figure 8] This shows another schematic diagram of the control system according to an embodiment of the present invention. [Figure 9] This shows yet another schematic diagram of the control system according to an embodiment of the present invention. [Figure 10] This shows a schematic block diagram of the control method according to an embodiment of the present invention. [Figure 11] This diagram shows a schematic flowchart of the control method for the energy storage system according to an embodiment of the present invention. [Modes for carrying out the invention]

[0042] The technical concepts of the embodiments of this application will be described clearly and in detail below with reference to the drawings described in the embodiments of this application. Clearly, the embodiments given are not all embodiments, but only a selection of embodiments of this application. All other embodiments that can be obtained by a person skilled in the art without creative effort based on the embodiments of this application are included within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art relating to this application. Terms used herein are solely for the purpose of describing specific embodiments and are not intended to limit this application. Terms such as “includes” and “has,” and any variations thereof, in the description of the specification, claims, and drawings herein are intended to cover non-exclusive inclusion. Terms such as “first,” “second,” etc., in the description of the specification, claims, and drawings herein are used merely to distinguish different subjects and should not be understood to indicate a particular order or hierarchical relationship.

[0044] As used herein, “Examples” means that a combination of specific features, structures, or properties described in the Examples may be included in at least one Example of the Application. The term as it appears throughout this Specification does not necessarily refer to the same Example, nor does it mean that each Example is mutually exclusive, independent, or substitutable for another Example. Those skilled in the art will understand, both explicitly and implicitly, that the Examples described herein may be combined with other Examples.

[0045] In the description of this application, unless otherwise specified or limited, the terms "connected" and "connected" may refer to direct connections, indirect connections via an intermediate medium, or internal communication between the two elements. A person skilled in the art will be able to understand the specific meaning of these terms in this application depending on the specific circumstances.

[0046] In this application, the term "and / or" merely describes the relationship between the related objects, meaning there can be three possible relationships. For example, "A and / or B" could refer to just A, both A and B, or just B. In addition, the " / " in this application generally indicates that the preceding and following related objects have an "or" relationship.

[0047] In the field of energy storage technology for power systems, new energy storage technologies integrate converter valves and energy storage valves, offering advantages such as a high degree of modularization, low transmission loss, good economic efficiency, and high operational reliability. For example, by integrating an energy storage valve on the DC side of the converter valve of a voltage source converter (VSC), AC-DC power conversion and energy storage can be achieved simultaneously. Compared to conventional energy storage technologies, new energy storage systems have higher voltage levels, larger capacities, stronger grid adjustment capabilities, and grid support functions, making them of significant research importance for new power systems that rely primarily on renewable energy.

[0048] Currently, no research is being conducted on the control structure of new energy storage systems.

[0049] In view of this, the embodiment of the present invention provides a control system for an energy storage system that can achieve coordinated control of the converter valve and the energy storage valve by a coordinated control subsystem.

[0050] Figure 1 shows a schematic diagram of a high-voltage DC direct-connection energy storage system applied to an embodiment of the present invention. As shown in Figure 1, the high-voltage DC direct-connection energy storage system 100 includes a VSC converter valve 110 and an energy storage valve 120. The energy storage valve 120 is connected to the DC side of the VSC converter valve 110. Optionally, the VSC converter valve 110 may employ an MMC structure as shown in Figure 2. Specifically, as shown in Figure 2, the VSC converter valve 110 may include six bridge arms, each consisting of two bridge arms connected in series. Here, each bridge arm contains n power modules (111_1, 111_2, ..., 111_n). As shown in Figure 3, the energy storage valve 120 includes m energy storage modules 121 (121_1, 121_2, ..., 121_m-1, 121_m) connected in series. Each energy storage module 121 may be configured by connecting a battery module 1212 to a power module 1211. Specifically, the power module 1211 may be a half-bridge type power module as shown in Figure 4a, or a full-bridge type power module as shown in Figure 4b. The battery module 1212 may be a battery module connected in series with a single branch, a battery module connected in parallel with multiple branches, or a battery module connected in series and parallel.

[0051] Furthermore, the control system for the energy storage system according to the embodiment of this application can be applied not only to the high-voltage DC direct-connection energy storage system 100 shown in Figure 1, but also to other energy storage systems, such as high-voltage AC direct-connection energy storage systems, and the embodiment of this application is not limited to these.

[0052] Figure 5 shows a schematic block diagram of a control system 200 of an energy storage system according to an embodiment of the present application. Selectively, the energy storage system may be the high-voltage DC direct-connection energy storage system 100 shown in Figure 1. The energy storage system may include a converter valve and an energy storage valve connected to the DC side of the converter valve. For example, the energy storage valve may be connected in parallel to the DC side of the converter valve. As shown in Figure 5, the control system 200 may include a coordinated control subsystem 210, a converter valve control subsystem 220, and an energy storage valve control subsystem 230. Here, the coordinated control subsystem 210 is used to transmit commands to control the operation of the converter valve control subsystem 220 and the energy storage valve control subsystem 230, the converter valve control subsystem 220 is used to control the operation of the converter valve according to the commands of the coordinated control subsystem 210, and the energy storage valve control subsystem 230 is used to control the operation of the energy storage valve according to the commands of the coordinated control subsystem 210.

[0053] Specifically, the cooperative control subsystem 210 can receive commands from a higher-level control system of the control system 200 and, in accordance with those commands, coordinately control the operation of the converter valve control subsystem 220 and the energy storage valve control subsystem 230. In other words, the cooperative control subsystem 210 communicates with the converter valve control subsystem 220 and the energy storage valve control subsystem 230, respectively. For example, the cooperative control subsystem 210 may send commands to the converter valve control subsystem 220 to control the operation of the converter valve, or it may send commands to the energy storage valve control subsystem 230 to control the operation of the energy storage valve.

[0054] In this embodiment, the cooperative control subsystem 210 controls the operation of the converter valve control subsystem 220 and the energy storage valve control subsystem 230, thereby enabling coordinated control of the converter valve and the energy storage valve.

[0055] Selectively, in embodiments of the present invention, the converter valve includes N first power modules. Furthermore, as shown in Figure 6, the converter valve control subsystem 220 includes a converter valve control unit 221 and N first power control units 222, where N is a positive integer. The converter valve control unit 221 is used to generate K first control commands for the N first power modules in accordance with commands from the cooperative control subsystem 210, where K is a positive integer less than or equal to N, and the N first power control units 222 are used to control the switching on or switching off of the N first power modules, respectively, in accordance with the K first control commands.

[0056] Specifically, the converter valve includes N first power modules, each of which may be a power module 111 as shown in Figure 2. In one example, the first power module may be a half-bridge type power module 1211 as shown in Figure 4a. In another example, the first power module may also be a full-bridge type power module 1211 as shown in Figure 4b. Selectively, the converter valve control subsystem 220 may include a converter valve control unit 221 and N first power control units 222, where each first power module in the N first power modules corresponds to one first power control unit 222, and the N first power control units 222 correspond to a common converter valve control unit 221. The converter valve control unit 221 receives commands from the cooperative control subsystem 210 and generates control commands for the K first power modules. In one example, K is equal to N, that is, each first power module corresponds to one control command, each first power control unit 222 corresponds to one control command, and each first power control unit 222 in the N first power control units 222 receives the corresponding control command generated by the converter valve control unit 221 and controls the operation of the corresponding first power module, for example, controlling the switching on or switching off of the corresponding first power module. In another example, K is less than N, that is, only some of the first power control units 222 of the N first power control units 222 receive the control command, and these some first power control units 222 may control the operation of the corresponding first power module according to the received control command, for example, controlling the switching on or switching off of the corresponding first power module. On the other hand, some other first power control units 222 that have not received the control command may control the corresponding first power module to a default state, for example, a default state of being switched off, or a default state of being switched on.

[0057] In this embodiment, a converter valve control unit 221 and N first power control units 222 are provided for N first power modules of the converter valve, and the converter valve control unit 221 communicates with the cooperative control subsystem 210 as a higher-level control unit for the N first power control units 222. In other words, the converter valve control subsystem 220 adopts a hierarchical design and modular design, making expansion and integration easy.

[0058] Selectively, in embodiments of the present invention, each of the N first power control units 222 is also used to upload state information of the corresponding first power module to the converter valve control unit 221.

[0059] Selectively, the status information of the first power module mainly includes states such as on, off, closed, and fault. In other words, the status information of the first power module is used to indicate to the converter valve control unit 221 which state the corresponding first power module is currently in: on, off, closed, or faulty. Furthermore, if the first power module is in a faulty state, the status information of the first power module is also used to indicate to the converter valve control unit 221 the currently existing fault of the corresponding first power module.

[0060] In this embodiment, the first power control unit 222 uploads the status information of the first power module to the converter valve control unit 221, which makes it easier for the converter valve control unit 221 to grasp the status of each first power module in a timely manner, thereby ensuring the reliability of system control.

[0061] Selectively, in the embodiments of the present invention, the converter valve control unit 221 is also used to upload valve control status information of the converter valve to the cooperative control subsystem 210.

[0062] Selectively, the valve control status information for the converter valve mainly includes three states: closed, faulty, or operating. In other words, the valve control status information is used to indicate to the cooperative control subsystem 210 which state the converter valve is currently in: closed, faulty, or operating. Furthermore, if the converter valve is in a faulty state, the valve control status information for the converter valve is also used to indicate to the cooperative control subsystem 210 the currently existing fault of the converter valve.

[0063] Selectively, the converter valve control unit 221 may determine the valve control state information of the converter valve based on the state information of the N first power modules reported by the N first power control units 222, and report the determined valve control state information to the cooperative control subsystem 210.

[0064] In this embodiment, the converter valve control unit 221 uploads the valve control status information of the converter valve to the cooperative control subsystem 210. This allows the cooperative control subsystem 210 to grasp the status of the converter valve in a timely manner, enabling better coordinated control of the operation of the converter valve and the energy storage valve, and ensuring the reliability of system control.

[0065] Selectively, in embodiments of the present invention, the converter valve control subsystem 220 includes a plurality of converter valve control units 221, each of which communicates with N first power control units 222, and the plurality of converter valve control units 221 communicate with each other.

[0066] Selectively, the multiple converter valve control units 221 may communicate with each other, exchange control information, and switch between master and slave roles. That is, one of the multiple converter valve control units 221 is the master control unit, while the others are slave control units, and if the master control unit fails, one of the slave control units can be set as the master control unit.

[0067] To make it clear, the plurality of converter valve control units 221 may be integrated into different plug-ins within the same device or may be provided in different devices. Similarly, the N first power control units 222 may be integrated into different plug-ins within the same device or may be provided in different devices. Furthermore, the converter valve control units 221 may be integrated into different plug-ins within the same device as the first power control units 222 or may be provided in different devices, and the embodiments of this application are not limited thereto.

[0068] In this embodiment, the converter valve control subsystem 220 includes a plurality of converter valve control units 221, and these plurality of converter valve control units 221 communicate with each other, and all of them communicate with N first power control units 222, thereby satisfying the requirements for a redundant design of the converter valve control subsystem 220 and ensuring the control reliability of the converter valve control subsystem 220.

[0069] Selectively, in embodiments of the present application, the energy storage valve comprises M energy storage modules, each of the M energy storage modules comprising a second power module and a battery module, where M is a positive integer. Furthermore, as shown in Figure 7, the energy storage valve control subsystem 230 comprises an energy storage valve control unit 231, M second power control units 232, and M battery control units 233. Here, the energy storage valve control unit 231 is used to generate Q second control commands for the M second power modules in the M energy storage modules, in accordance with the commands of the cooperative control subsystem 210, where Q is a positive integer less than or equal to M; the M second power control units 232 are used to control the switching on or off of the M second power modules, in accordance with the Q second control commands; and the M battery control units 233 are used to control the charging and discharging of the M battery modules in the M energy storage modules, respectively.

[0070] Specifically, the energy storage valve includes M energy storage modules, each of which may be an energy storage module 121 as shown in Figure 3, and each energy storage module includes a second power module and a battery module connected in parallel. In other words, the energy storage valve includes M second power modules and M battery modules. In one example, the second power module may be a half-bridge type power module 1211 as shown in Figure 4a. In another example, the second power module may be a full-bridge type power module 1211 as shown in Figure 4b. Selectively, the energy storage valve control subsystem 230 may include an energy storage valve control unit 231, M second power control units 232, and M battery control units 233, where each of the M second power modules corresponds to one second power control unit 232, and each of the M battery modules corresponds to one battery control unit 233, while the M second power control units 232 and M battery control units 233 correspond to a common energy storage valve control unit 231. The energy storage valve control unit 231 is responsible for receiving commands from the cooperative control subsystem 210 and generating control commands for the Q second power modules. In one example, Q is equal to M, that is, each second power module corresponds to one control command, each second power control unit 232 corresponds to one control command, and each second power control unit 232 in the M second power control units 232 receives the corresponding control command generated by the energy storage valve control unit 231 and controls the operation of the corresponding second power module, for example, controlling the switching on or off of the corresponding second power module.In another example, Q is less than M, meaning that only some of the M second power control units 232 receive a control command, and these some second power control units 232 control the operation of the corresponding second power module according to the received control command, for example, by controlling the switching on or off of the corresponding second power module. On the other hand, the other some second power control units 232 that have not received a control command may control the corresponding second power module to a default state, for example, the default state of being off, or the default state of being on. In addition, each battery control unit 233 in the M battery control units 233 controls the operation of the corresponding battery module, for example, by controlling the charging and discharging of the corresponding battery module.

[0071] In this embodiment, an energy storage valve control unit 231, M second power control units 232, and M battery control units 233 are provided for M second power modules and M battery modules in the energy storage valve. The energy storage valve control unit 231 communicates with the cooperative control subsystem 210 as a higher-level control unit for the M second power control units 232. In other words, the energy storage valve control subsystem 230 adopts a hierarchical and modular design, making expansion and integration easy. Furthermore, the converter valve and the energy storage valve are controlled separately, and the technology of the converter valve control subsystem 220 is relatively mature. The energy storage valve control subsystem 230 can be expanded and developed based on the converter valve control subsystem 220, making engineering implementation easy.

[0072] The first power module and the second power module may be the same or different. The embodiments of this application are not limited to this.

[0073] Selectively, in embodiments of the present invention, the energy storage valve control unit 231 is also used to generate P third control commands for the M battery modules in accordance with the commands of the cooperative control subsystem 210, where P is a positive integer less than or equal to M, and the M battery control units 233 are used to charge and discharge each of the M battery modules in accordance with the P third control commands.

[0074] In one example, P is equal to M, meaning each battery module corresponds to one control command, and each battery control unit 233 corresponds to one control command. Each of the M battery control units 233 receives the corresponding control command generated by the energy storage valve control unit 231 and controls the operation of the corresponding battery module, for example, by controlling the charging and discharging of the corresponding battery module. In another example, P is less than M, meaning only some of the M battery control units 233 receive the control command, and these some battery control units 233 control the operation of the corresponding battery module according to the received control command, for example, by controlling the charging and discharging of the corresponding battery module. On the other hand, some of the other battery control units 233 that have not received the control command may control the corresponding battery module to a default state, for example, a default of not charging or a default of not discharging.

[0075] In this embodiment, the M battery control units 233 may communicate directly with the energy storage valve control unit 231, making it easier for the second power control unit 232 and the battery control unit 233 to control the second power module and the battery module in parallel, thereby improving the control efficiency of the system.

[0076] Selectively, in embodiments of the present invention, each of the M battery control units 233 is also used to upload the status information of the corresponding battery module to the energy storage valve control unit 231.

[0077] Selectively, the state information of the battery module may include at least one battery parameter, such as the battery module's voltage, charge level, temperature, state of charge (SOC), or current. Selectively, the state information of the battery module may also be a function of the various battery parameters described above. The battery control unit 233 can upload the corresponding state information of the battery module in response to a request from the energy storage valve control unit 231. In other words, the battery control unit 233 only needs to upload the required state information according to the state information required by the energy storage valve control unit 231.

[0078] In this embodiment, the battery control unit 233 uploads the status information of the corresponding battery module to the energy storage valve control unit 231, allowing the energy storage valve control unit 231 to grasp the status of the battery module in a timely manner and perform appropriate control on the battery module, thereby ensuring the control reliability of the energy storage valve control subsystem 230.

[0079] Selectively, in the embodiments of the present invention, the M second power control units 232 are also used to generate R fourth control commands for the M battery modules in accordance with the Q second control commands, where R is a positive integer less than or equal to M, and the M battery control units 233 are used to charge and discharge the M battery modules in accordance with the R fourth control commands.

[0080] In other words, the M battery control units 233 do not communicate directly with the energy storage valve control unit 231, but rather communicate indirectly with the energy storage valve control unit 231 via the M second power control units 232.

[0081] In one example, R is equal to M, meaning each battery module corresponds to one control command, and each battery control unit 233 corresponds to one control command. Each of the M battery control units 233 receives the corresponding control command generated by the corresponding second power control unit 232 and controls the operation of the corresponding battery module, for example, by controlling the charging and discharging of the corresponding battery module. In another example, R is less than M, meaning only some of the M battery control units 233 receive the control command transmitted by the corresponding second power control unit 232, and these some battery control units 233 may control the operation of the corresponding battery module according to the received control command, for example, by controlling the charging and discharging of the corresponding battery module. On the other hand, some of the other battery control units 233 that have not received a control command may control the corresponding battery module to a default state, for example, a default of not charging or a default of not discharging.

[0082] In this embodiment, M battery control units 233 are each controlled by M second power control units 232, thereby reducing the communication load on the energy storage valve control unit 231.

[0083] Selectively, in the embodiments of the present invention, each of the M battery control units 233 is also used to upload the status information of the corresponding battery module to the corresponding second power control unit 232.

[0084] Similar to the above embodiment, the state information of the battery module may include at least one battery parameter such as the voltage, charge amount, temperature, state of charge (SOC), and current of the battery module. Selectively, the state information of the battery module may be a function of the various battery parameters described above. The battery control unit 233 can upload the state information of the battery module to the second power control unit 232 based on the content of the fourth control command. In other words, the battery control unit 233 should upload the information instructed by the fourth control command.

[0085] In this embodiment, the battery control unit 233 uploads the status information of the corresponding battery module to the second power control unit 232, which in turn provides timely feedback of the battery module's status to the energy storage valve control unit 231, enabling appropriate control of the battery module. This ensures the control reliability of the energy storage valve control subsystem 230.

[0086] Selectively, in embodiments of the present invention, each of the M second power control units 232 is also used to upload state information of the corresponding second power module to the energy storage valve control unit 231.

[0087] Selectively, the status information of the second power module mainly includes states such as on, off, closed, and fault. In other words, the status information of the second power module is used to indicate to the energy storage valve control unit 231 which state the corresponding second power module is currently in: on, off, closed, or faulty. Furthermore, if the second power module is in a faulty state, the status information of the second power module is also used to indicate to the energy storage valve control unit 231 the currently existing fault of the corresponding second power module.

[0088] In this embodiment, the second power control unit 232 uploads the status information of the second power module to the energy storage valve control unit 231, which makes it easier for the energy storage valve control unit 231 to grasp the status of each second power module in a timely manner, thereby ensuring the reliability of system control.

[0089] Selectively, in embodiments of the present invention, the energy storage valve control unit 231 is also used to upload valve control status information of the energy storage valve to the cooperative control subsystem 210.

[0090] Selectively, the valve control state information for the energy storage valve mainly includes three states: closed, faulty, or operating. In other words, the valve control state information is used to indicate to the coordinated control subsystem 210 which state the energy storage valve is currently in: closed, faulty, or operating. Furthermore, if the energy storage valve is in a faulty state, the valve control state information for the energy storage valve is also used to indicate to the coordinated control subsystem 210 the currently existing fault of the energy storage valve.

[0091] Selectively, the energy storage valve control unit 231 may determine the valve control state information of the energy storage valve based on the state information of the M second power modules reported by the M second power control units 232 and the state information of the M battery modules reported by the M battery control units 233, and then report the determined valve control state information to the cooperative control subsystem 210.

[0092] In this embodiment, the energy storage valve control unit 231 uploads the valve control status information of the energy storage valve to the cooperative control subsystem 210. This allows the cooperative control subsystem 210 to grasp the status of the energy storage valve in a timely manner, enabling better coordinated control of the operation of the converter valve and the energy storage valve, and ensuring the reliability of system control.

[0093] Selectively, in the embodiments of the present invention, a second power control unit 232 and a battery control unit 233, which correspond to the same energy storage module, communicate with each other.

[0094] Selectively, in embodiments of the present application, the energy storage valve control subsystem 230 further includes a battery monitoring unit for acquiring battery data for the M battery modules.

[0095] Selectively, the battery data may include all battery parameters such as the voltage, charge level, temperature, state of charge (SOC), and current of the battery module. Furthermore, the battery control unit 233 spontaneously reports this battery data to the battery monitoring unit.

[0096] In one example, each of the battery control units 233 may communicate with the battery monitoring unit, that is, each battery control unit 233 directly reports battery data of the corresponding battery module to the battery monitoring unit.

[0097] In another example, the battery control units 233 are connected via daisy-chain communication, and only the first and last two battery control units 233 of the daisy-chain communicate directly with the battery monitoring unit. That is, the first and last two battery control units 233 of the daisy-chain can aggregate the battery data acquired by all the battery control units 233 and upload the aggregated battery data to the battery monitoring unit.

[0098] Selectively, daisy-chain communication may be employed among the M battery control units 233 to acquire battery data for the M battery modules, regardless of which of the above examples the battery monitoring unit uses.

[0099] Selectively, in this embodiment, the energy storage valve control subsystem 230 includes a plurality of energy storage valve control units 231, each of which communicates with M second power control units 232, and the plurality of energy storage valve control units 232 communicate with each other.

[0100] Selectively, the multiple energy storage valve control units 231 may communicate with each other, exchange control information, and switch between master and slave roles. That is, one of the multiple energy storage valve control units 231 is the master control unit, while the others are slave control units, and if the master control unit fails, one of the slave control units can be set as the master control unit.

[0101] To make it clear, the multiple energy storage valve control units 231 may be integrated into different plug-ins within the same device or may be provided in different devices. Similarly, the M second power control units 232 may be integrated into different plug-ins within the same device or may be provided in different devices. The M battery control units 233 may be integrated into different plug-ins within the same device or may be provided in different devices. Furthermore, the energy storage valve control units 231, the second power control units 232, and the battery control units 233 may be integrated into different plug-ins within the same device or may be provided in different devices. The embodiments of this application are not limited thereto.

[0102] In this embodiment, the energy storage valve control subsystem 230 includes a plurality of energy storage valve control units 231, and these plurality of energy storage valve control units 231 communicate with each other, and all of them communicate with M second power control units 232, thereby satisfying the requirements for a redundant design of the energy storage valve control subsystem 230 and ensuring the control reliability of the energy storage valve control subsystem 230.

[0103] Selectively, in embodiments of the present invention, the cooperative control subsystem 210 includes a plurality of system control units, each of which communicates with the converter valve control subsystem 220 and the energy storage valve control subsystem 230, and the plurality of system control units communicate with each other.

[0104] Selectively, the multiple system control units may communicate with each other, exchange control information, and switch between master and slave roles. That is, one of the multiple system control units is the master control unit, while the others are slave control units, and if the master control unit fails, one of the slave control units can be set as the master control unit.

[0105] To make it clear, the multiple system control units may be integrated into different plug-ins within the same device, or they may be located in different devices. The embodiments of this application are not limited thereto.

[0106] In this embodiment, the cooperative control subsystem 210 includes a plurality of system control units, and these system control units communicate with each other, and all of them communicate with the converter valve control subsystem 220 and the energy storage valve control subsystem 230, thereby satisfying the requirements for a redundant design of the cooperative control subsystem 210 and ensuring the control reliability of the cooperative control subsystem 210.

[0107] Selectively, in the embodiments of the present application, the converter valve control subsystem 220 is integrated into the converter valve, and the energy storage valve control subsystem 230 is integrated into the energy storage valve.

[0108] The control system of the energy storage system according to the embodiment of the present invention will be described in detail below with reference to Figures 8 and 9.

[0109] Figure 8 is a three-layer control structure diagram of the energy storage valve control subsystem. As shown in Figure 8, the control system includes a cooperative control subsystem, a converter valve control subsystem, and an energy storage valve control subsystem. The cooperative control subsystem includes a system control unit A and a system control unit B, which communicate with each other and exchange control information. The converter valve control subsystem includes two converter valve control units (converter valve control unit A and converter valve control unit B, which communicate with each other and exchange control information) and N first power control units (first power control unit 1, first power control unit 2, ..., first power control unit N-1, first power control unit N). The energy storage valve control subsystem includes N energy storage valve control units (energy storage valve control unit A and energy storage valve control unit B, which communicate with each other and exchange control information), M second power control units (second power control unit 1, second power control unit 2, ..., second power control unit M), M battery control units (battery control unit 1, battery control unit 2, ..., battery control unit M), and a battery monitoring unit. Here, system control unit A generates control commands and transmits them to converter valve control unit A and energy storage valve control unit A, and system control unit B generates control commands and transmits them to converter valve control unit B and energy storage valve control unit B. The converter valve control unit A and the converter valve control unit B transmit on / off commands to the first power control unit 1-N in accordance with the control commands generated by the system control unit A and the system control unit B respectively, and the first power control unit 1-N transmits the controlled state of the first power module to the converter valve control unit A and the converter valve control unit B.The converter valve control unit A transmits the valve control status of the converter valve to the system control unit A, and the converter valve control unit B transmits the valve control status of the converter valve to the system control unit B. The energy storage valve control unit A and the energy storage valve control unit B transmit on / off commands to the second power control unit 1-M according to the control commands generated by the system control unit A and the system control unit B, respectively, and the second power control unit 1-M transmits the status of the second power module to the energy storage valve control unit A and the energy storage valve control unit B. The second power control unit 1-M can further transmit charge / discharge commands to the battery control unit 1-M, and the battery control unit 1-M controls the charging and discharging of the battery module according to the charge / discharge commands and uploads the battery state of the battery module to the second power control unit 1-M, and on the other hand, the battery control units 1-M are connected by daisy-chain communication and the battery data acquired by the battery control unit 1-M is aggregated to the battery monitoring unit.

[0110] Figure 9 is a two-layer control structure diagram of the energy storage valve control subsystem. As shown in Figure 9, the control system includes a cooperative control subsystem, a converter valve control subsystem, and an energy storage valve control subsystem. The cooperative control subsystem includes a system control unit A and a system control unit B, which communicate with each other and exchange control information. The converter valve control subsystem includes two converter valve control units (converter valve control unit A and converter valve control unit B, which communicate with each other and exchange control information) and N first power control units (first power control unit 1, first power control unit 2, ..., first power control unit N-1, first power control unit N). The energy storage valve control subsystem includes N energy storage valve control units (energy storage valve control unit A and energy storage valve control unit B, which communicate with each other and exchange control information), M second power control units (second power control unit 1, second power control unit 2, ..., second power control unit M), M battery control units (battery control unit 1, battery control unit 2, ..., battery control unit M), and a battery monitoring unit. Here, system control unit A generates control commands and transmits them to converter valve control unit A and energy storage valve control unit A, and system control unit B generates control commands and transmits them to converter valve control unit B and energy storage valve control unit B. The converter valve control unit A and the converter valve control unit B transmit on / off commands to the first power control unit 1-N in accordance with the control commands generated by the system control unit A and the system control unit B respectively, and the first power control unit 1-N transmits the status information of the controlled first power module to the converter valve control unit A and the converter valve control unit B.The energy storage valve control unit A and the energy storage valve control unit B transmit on / off commands to the second power control unit 1-M and charge / discharge commands to the battery control unit 1-M, respectively, according to the control commands generated by the system control unit A and the system control unit B. The second power control unit 1-M transmits status information of the second power module to the energy storage valve control unit A and the energy storage valve control unit B. The battery control unit 1-M, on the one hand, controls the charging and discharging of the battery module according to the charge / discharge commands and transmits the battery state of the battery module to the energy storage valve control unit A and the energy storage valve control unit B. On the other hand, the battery control units 1-M are connected via daisy-chain communication and aggregate the battery data acquired by the battery control unit 1-M to the battery monitoring unit. Furthermore, the second power control unit and the battery control unit corresponding to the same energy storage module communicate with each other and exchange control information.

[0111] Figure 10 shows a schematic block diagram of a control method 300 for an energy storage system according to an embodiment of the present application. The energy storage system includes a converter valve and an energy storage valve connected to the DC side of the converter valve. Optionally, the control method may be performed by the coordinated control subsystem described above. As shown in Figure 10, the control method 300 includes the following steps:

[0112] S310: A first command for controlling the operation of the converter valve is transmitted to the converter valve control subsystem, and a second command for controlling the operation of the energy storage valve is transmitted to the energy storage valve control subsystem.

[0113] Furthermore, the contents of the control method 300 may refer to each step performed by the cooperative control subsystem 210. Optionally, the control method 300 may further include each step performed by the converter valve subsystem 220 and the energy storage valve subsystem 230. For simplicity, their explanation is omitted here.

[0114] Figure 11 is a schematic flowchart of the control method for the energy storage system based on the control structure shown in Figure 8. Specifically, the control method includes the following steps: (1) The system control unit in the cooperative control subsystem determines the valve control commands for the converter valve and energy storage valve in different control modes through control mode selection, power calculation, power control (AC power / DC power), and internal / external double-loop control (active power / reactive power). (2) In the converter valve control subsystem, the converter valve control unit performs bridge arm current control, capacitor voltage equalization control, and modulation to generate on / off commands for the first power module in the converter valve. (3) The first power control unit in the converter valve control subsystem performs on / off control of the first power module. (4) In the energy storage valve control subsystem, the energy storage valve control unit performs battery current control, battery state equalization control, and modulation to generate on / off commands for the second power module in the energy storage valve. (5) Furthermore, the second power control unit in the energy storage valve control subsystem controls the switching on and off of the second power module. (6) Finally, the battery control unit in the energy storage valve control subsystem further controls the charging and discharging of the battery module in the energy storage valve according to the charge and discharge commands generated by the second power control unit, and at the same time aggregates and calculates the battery information of the battery module.

[0115] To ensure that this is understood, in each embodiment of the present application, the magnitude of the number of each process does not indicate the order of execution, and the execution order of each process should be determined by its function and inherent logic, and does not limit the implementation process of the embodiments of the present application.

[0116] Embodiments of the present invention further provide a computer-readable storage medium for storing computer programs.

[0117] Selectively, the computer-readable storage medium may be applied to the control system according to the embodiment of the present invention, and the computer program causes the computer to execute the corresponding process implemented by the control system in each method of the embodiment of the present invention, but for simplicity, such explanation is omitted here.

[0118] Embodiments of the present invention further provide computer program products including computer program instructions.

[0119] Selectively, the computer program product may be applied to a control system according to an embodiment of the present application, and the computer program command causes the computer to execute the corresponding process implemented by the control system in each method of the embodiment of the present application, but for simplicity, such explanation is omitted here.

[0120] Embodiments of the present invention further provide computer programs.

[0121] Selectively, the computer program may be applied to a control system according to an embodiment of the present invention, and when the computer program is executed on a computer, the computer is made to execute the corresponding processes realized by the control system in each method of the embodiment of the present invention, but for the sake of brevity, such explanation is omitted here.

[0122] Selectively, embodiments of the present application further provide an energy storage system comprising a converter valve and an energy storage valve connected to the DC side of the converter valve, and the high-pressure direct-acting energy storage system may further include the control systems described in each of the embodiments.

[0123] Selectively, in the embodiments of the present application, the converter valve is a VSC converter valve.

[0124] Furthermore, in the embodiment of the present invention, the VSC converter valve employs a modular multilevel converter (MMC) structure.

[0125] The above describes only embodiments of the present application, and the scope of protection of this application is not limited thereto. A person skilled in the art will readily conceive of any modifications or substitutions within the technical scope described in this application, and all of these should fall within the scope of protection of this application. Therefore, the scope of protection of this application should be the same as the scope of protection of the claims.

Claims

1. A control system for an energy storage system, wherein the energy storage system includes a converter valve and an energy storage valve connected to the DC side of the converter valve, and the control system includes a cooperative control subsystem, a converter valve control subsystem, and an energy storage valve control subsystem. The aforementioned cooperative control subsystem is used to transmit commands to control the operation of the converter valve control subsystem and the energy storage valve control subsystem. The converter valve control subsystem is used to control the operation of the converter valve in accordance with the commands of the cooperative control subsystem. The converter valve includes N first power modules, and the converter valve control subsystem includes a converter valve control unit and N first power control units, where N is a positive integer. The converter valve control unit is used to generate K first control commands for the N first power modules in accordance with the commands of the cooperative control subsystem, where K is a positive integer less than or equal to N. The N first power control units are used to control the switching on or off of the N first power modules, respectively, according to the K first control commands. The control system for an energy storage system is characterized in that the converter valve control unit is also used to upload valve control status information of the converter valve to the cooperative control subsystem.

2. The control system according to claim 1, characterized in that each of the N first power control units is also used to upload the state information of the corresponding first power module to the converter valve control unit.

3. The energy storage valve includes M energy storage modules, each of the M energy storage modules includes a second power module and a battery module, and the energy storage valve control subsystem includes an energy storage valve control unit, M second power control units, and M battery control units, where M is a positive integer. The energy storage valve control unit is used to generate Q second control commands for M second power modules in the M energy storage modules, in accordance with the commands of the cooperative control subsystem, where Q is a positive integer less than or equal to M. The M second power control units are used to control the switching on or off of the M second power modules, respectively, according to the Q second control commands. The control system according to claim 1, characterized in that the M battery control units are used to control the charging and discharging of each of the M battery modules in the M energy storage modules.

4. The control system according to claim 3, wherein the energy storage valve control unit is also used to generate P third control commands for the M battery modules in accordance with the commands of the cooperative control subsystem, where P is a positive integer less than or equal to M, and the M battery control units are used to control the charging and discharging of each of the M battery modules in accordance with the P third control commands.

5. The control system according to claim 4, characterized in that each of the M battery control units is also used to upload the status information of the corresponding battery module to the energy storage valve control unit.

6. The control system according to claim 3, wherein the M second power control units are also used to generate R fourth control commands for the M battery modules in accordance with the Q second control commands, where R is a positive integer less than or equal to M, and the M battery control units are used to control the charging and discharging of the M battery modules in accordance with the R fourth control commands.

7. The control system according to claim 6, characterized in that each of the M battery control units is also used to upload the status information of the corresponding battery module to the corresponding second power control unit.

8. The control system according to any one of claims 3 to 7, characterized in that the energy storage valve control unit is also used to upload valve control status information of the energy storage valve to the cooperative control subsystem.

9. The control system according to any one of claims 3 to 7, characterized in that each of the M second power control units is also used to upload the state information of the corresponding second power module to the energy storage valve control unit.

10. The control system according to any one of claims 3 to 7, characterized in that a second power control unit corresponding to the same energy storage module and the battery control unit communicate with each other.

11. The energy storage valve control subsystem is The control system according to any one of claims 3 to 7, further comprising a battery monitoring unit for acquiring battery data of the M battery modules.

12. The control system according to any one of claims 3 to 7, characterized in that M is a positive integer greater than 1, and the M battery control units are connected by daisy-chain communication.

13. The control system according to claim 1 or 2, wherein the converter valve control subsystem includes a plurality of converter valve control units, each of the plurality of converter valve control units communicates with the N first power control units, and the plurality of converter valve control units communicate with each other.

14. The control system according to any one of claims 3 to 7, wherein the energy storage valve control subsystem includes a plurality of energy storage valve control units, each energy storage control unit in the plurality of energy storage valve control units communicates with the M second power control units, and the plurality of energy storage valve control units communicate with each other.

15. The control system according to any one of claims 1 to 7, wherein the cooperative control subsystem includes a plurality of system control units, each system control unit in the plurality of system control units communicates with the converter valve control subsystem and the energy storage valve control subsystem, and the plurality of system control units communicate with each other.

16. The control system according to any one of claims 1 to 7, characterized in that the converter valve control subsystem is integrated into the converter valve, and the energy storage valve control subsystem is integrated into the energy storage valve.

17. An energy storage system comprising a converter valve and an energy storage valve connected to the DC side of the converter valve, further comprising the control system according to any one of claims 1 to 7.

18. A method for controlling an energy storage system, wherein the energy storage system includes a converter valve and an energy storage valve connected to the DC side of the converter valve, and the control method is The cooperative control subsystem includes transmitting a first command to the converter valve control subsystem for controlling the operation of the converter valve, and transmitting a second command to the energy storage valve control subsystem for controlling the operation of the energy storage valve. The converter valve includes N first power modules, and the converter valve control subsystem includes a converter valve control unit and N first power control units, where N is a positive integer. The control method further includes, The converter valve control unit generates K first control commands for the N first power modules in accordance with the commands of the cooperative control subsystem, where K is a positive integer less than or equal to N. The N first power control units each control the switching on or off of the N first power modules according to the K first control commands. A method for controlling an energy storage system, characterized in that the converter valve control unit uploads valve control status information of the converter valve to the cooperative control subsystem.

Images