Control System and Control Method of Energy Storage System 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

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

Background Art

[0002] In the field of energy storage technologies 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, a control method therefor, and an energy storage system that can achieve coordinated control of 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 can realize the cooperative control of the converter valve and the energy storage valve by controlling the operations of the converter valve control subsystem and the energy storage valve control subsystem.

[0007] In a possible embodiment, 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 according to the commands of the cooperative control subsystem, where K is a positive integer not exceeding 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.

[0008] In this embodiment, for the N first power modules of the converter valve, a converter valve control unit and N first power modules are provided, and the converter valve control unit communicates with the cooperative control subsystem as the upper control unit of the N first power control units. That is, by adopting a hierarchical design and a modular design for the converter valve control subsystem, it is easy to expand and integrate.

[0009] In a possible implementation manner, each of the N first power control units in 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.

[0010] In this embodiment, by the first power control unit uploading the state information of the first power module to the converter valve control unit, it is easy for the converter valve control unit to timely grasp the state of each first power module, and the reliability of system control can be ensured.

[0011] In a possible embodiment, the converter valve control unit is also used to upload the valve control state information of the converter valve to the coordinated control subsystem.

[0012] In this embodiment, by the converter valve control unit uploading the valve control state information of the converter valve to the coordinated control subsystem, it becomes easier for the coordinated control subsystem to timely grasp the state of the converter valve, better coordinate and control the operations of the converter valve and the energy storage valve, and ensure the reliability of system control.

[0013] In a possible embodiment, the energy storage valve includes M energy storage modules, each energy storage module in the M energy storage modules includes a second power module and a battery module, the energy storage valve control subsystem includes an energy storage valve control unit, M second power control units, and M battery control units, 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 according to the commands of the coordinated control subsystem, Q is a positive integer less than or equal to M, the M second power control units are used to respectively control the turning on or off of the M second power modules according to the Q second control commands, and the M battery control units are used to respectively control the charge and discharge of the M battery modules in the M energy storage modules.

[0014] In this embodiment, for the M second power modules and M battery modules in the energy storage valve, an energy storage valve control unit, M second power control units, and M battery control units are provided, and the energy storage valve control unit communicates with the cooperative control subsystem as the upper control unit of the M second power control units. That is, by adopting hierarchical design and modular design for the energy storage valve control subsystem, expansion and integration are facilitated. Also, the converter valve and the energy storage valve are controlled separately. The technology of the converter valve control subsystem is relatively mature, and the energy storage valve control subsystem can be expanded and developed based on the converter valve control subsystem, making it easy to realize the engineering.

[0015] In a possible embodiment, the energy storage valve control unit is also used to generate P third control commands for the M battery modules according to the commands of the cooperative control subsystem, where P is a positive integer not exceeding M. The M battery control units are used to respectively control the charging and discharging of the M battery modules according to the P third control commands.

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

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

[0018] In this embodiment, the battery control unit uploads the state information of the corresponding battery module to the energy storage valve control unit, so that the energy storage valve control unit can timely grasp the state of the battery module and perform corresponding control on the battery module, thereby ensuring the control reliability of the energy storage valve control subsystem.

[0019] In a possible embodiment, the M second power control units are also used to respectively generate R fourth control commands for the M battery modules 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 respectively control the charging and discharging of the M battery modules according to the R fourth control commands.

[0020] In this embodiment, the M battery control units are respectively controlled by the M second power control units, which can reduce the communication load of the energy storage valve control unit.

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

[0022] In this embodiment, the battery control unit uploads the state information of the corresponding battery module to the second power control unit, so that the second power control unit timely feeds back the state of the battery module to the energy storage valve control unit and can perform corresponding control on the battery module, thereby ensuring the control reliability of the energy storage valve control subsystem.

[0023] In a possible embodiment, the energy storage valve control unit is also used to upload the valve control state 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, so that the cooperative control subsystem can easily grasp the state of the energy storage valve in a timely manner, better cooperate and control 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, the energy storage valve control unit can easily grasp the state of each second power module in a timely manner and ensure the reliability of system control.

[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 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 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 redundant design of the coordinated control subsystem and ensuring the control reliability of the coordinated control subsystem.

[0036] In a possible embodiment, 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 aspect, there is provided an energy storage system including a converter valve and an energy storage valve connected to the DC side of the converter valve, and the energy storage system further includes a control system according to the first aspect and any possible embodiments thereof.

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

[0039] In a fourth aspect, there is provided a computer-readable storage medium used for storing a computer program for causing a computer to execute the method according to the first aspect and any possible embodiments of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] For a clearer description of the technical solutions of the embodiments of the present application, the drawings to be used in the embodiments of the present application are briefly described below. Obviously, the following drawings only show some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative efforts.

[0041]

Figure 1

Figure 2

Figure 3

Figure 4a

Figure 4b

Figure 5

Figure 6

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Figure 11

DETAILED DESCRIPTION OF THE INVENTION

[0042] Hereinafter, with reference to the drawings described in the embodiments of the present application, the technical solutions of the embodiments of the present application will be clearly and detailedly described. Obviously, the cited embodiments are only some of the embodiments of the present application, not all of them. Based on the embodiments of the present application, all other embodiments that can be obtained by those skilled in the art without creative efforts are included within the protection scope of the present application.

[0043] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" in the description of this application, the claims, and the above drawings, and any variations thereof, are intended to cover non-exclusive inclusion. The terms such as "first" and "second" in the description of this application, the claims, and the above drawings are used only to distinguish different objects and should not be understood as indicating a specific order or a primary-secondary relationship.

[0044] As used herein, "embodiment" means that a combination of specific features, structures, or characteristics described in an embodiment may be included in at least one embodiment of this application. This term appearing in each part of this specification does not necessarily refer to the same embodiment, nor does it mean mutually exclusive, independent, or alternative embodiments with other embodiments. One of ordinary skill in the art can explicitly or implicitly understand that the embodiments described in this specification may be combined with other embodiments.

[0045] In the description of this application, unless otherwise specified or limited, the terms "connected" and "connected to" may mean directly connected or indirectly connected through an intermediate medium, or may be an internal communication between the two elements. One of ordinary skill in the art can understand the specific meaning of these terms in this application according to the specific situation.

[0046] In this application, the term "and / or" is only used to explain the relationship between related objects and means that there can be three relationships. Taking "A and / or B" as an example, there can be three cases: simply A, both A and B, and simply B. Also, " / " in this application generally indicates that the related objects before and after have an "or" relationship.

[0047] In the field of energy storage technologies for power systems, new energy storage technologies integrate converter valves and energy storage valves, and have advantages such as a high degree of modularization, low transmission losses, good economic effects, and high operation 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 with conventional energy storage technologies, the new energy storage system has a higher voltage level, a larger capacity, a stronger power grid regulation ability and power grid support function, and has important research significance for a new type of power system mainly composed of new energy.

[0048] Currently, the control structure of the new energy storage system has not been studied.

[0049] In view of this, the embodiments of the present application provide a control system for an energy storage system that can realize the coordinated control of a converter valve and an energy storage valve by a coordinated control subsystem.

[0050] Figure 1 shows a schematic structural diagram of a high-voltage DC directly-connected energy storage system applied to an embodiment of the present application. As shown in Figure 1, the high-voltage DC directly-connected 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 adopt the MMC structure shown in Figure 2. Specifically, as shown in Figure 2, the VSC converter valve 110 may include six bridge arms in which two bridge arms are connected in series. Here, each bridge arm includes 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 shown in Figure 4a, or a full-bridge type power module shown in Figure 4b. The battery module 1212 may be a battery module connected in series in a single branch, or a battery module connected in parallel in a plurality of branches, or a battery module connected in series and parallel.

[0051] It should be noted that the control system of the energy storage system according to the embodiment of the present application can be applied not only to the high-voltage DC directly-connected energy storage system 100 shown in Figure 1, but also to other energy storage systems, such as a high-voltage AC directly-connected energy storage system, and the embodiment of the present application does not limit this.

[0052] FIG. 5 shows a schematic block diagram of a control system 200 of an energy storage system according to an embodiment of the present application. Optionally, the energy storage system may be the high-voltage DC direct-connected type energy storage system 100 shown in FIG. 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 FIG. 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 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 according to the commands of the coordinated control subsystem 210. 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 coordinated control subsystem 210 receives commands from the upper control system of the control system 200 and can play a role in coordinately controlling the operations of the converter valve control subsystem 220 and the energy storage valve control subsystem 230 according to the commands of the upper control system. In other words, the coordinated control subsystem 210 communicates with the converter valve control subsystem 220 and the energy storage valve control subsystem 230 respectively. For example, the coordinated control subsystem 210 may send commands to the converter valve control subsystem 220 to control the operation of the converter valve, and the coordinated control subsystem 210 may also 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 can realize the cooperative control of the converter valve and the energy storage valve by controlling the operations of the converter valve control subsystem 220 and the energy storage valve control subsystem 230.

[0055] Optionally, in the embodiment of the present application, the converter valve includes N first power modules. Further, as shown in FIG. 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 according to the commands of the cooperative control subsystem 210, where K is a positive integer not exceeding N. The N first power control units 222 are used to control the connection or disconnection of the N first power modules respectively according to the K first control commands.

[0056] Specifically, the converter valve includes N first power modules, and the first power module may be the power module 111 shown in FIG. 2. In one example, the first power module may be the half-bridge type power module 1211 shown in FIG. 4a. In another example, the first power module may also be the full-bridge type power module 1211 shown in FIG. 4b. Optionally, the converter valve control subsystem 220 may include a converter valve control unit 221 and N first power control units 222, that is, each first power module in the N first power modules corresponds to one first power control unit 222, while the N first power control units 222 correspond to a common converter valve control unit 221. The converter valve control unit 221 is responsible for receiving the commands of the coordination control subsystem 210 and generating control commands for 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, is responsible for controlling the activation or deactivation of the corresponding first power module. In another example, K is less than N, that is, only some of the N first power control units 222 receive control commands, and these some first power control units 222 may control the operation of the corresponding first power modules according to the received control commands, for example, control the activation or deactivation of the corresponding first power modules. On the other hand, another part of the first power control units 222 that do not receive control commands may control the corresponding first power modules to be in a default state, for example, a default deactivated state or a default activated state.

[0057] In this embodiment, for N first power modules among the converter valves, a converter valve control unit 221 and N first power control units 222 are provided, and the converter valve control unit 221 communicates with the cooperative control subsystem 210 as the upper control unit of the N first power control units 222. That is, by adopting hierarchical design and modular design for the converter valve control subsystem 220, expansion and integration are facilitated.

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

[0059] Optionally, the state information of the first power module mainly includes states such as on, off, closed, and faulty. That is, the state information of the first power module is used to indicate to the converter valve control unit 221 which state among on, off, closed, and faulty the corresponding first power module is currently in. Further, when the first power module is in a faulty state, the state information of the first power module is also used to indicate the existing fault of the corresponding first power module to the converter valve control unit 221.

[0060] In this embodiment, by the first power control unit 222 uploading the state information of the first power module to the converter valve control unit 221, it becomes easier for the converter valve control unit 221 to timely grasp the state of each first power module, and the reliability of system control can be ensured.

[0061] Optionally, in the embodiment of the present application, the converter valve control unit 221 is also used to upload the valve control state information of the converter valve to the cooperative control subsystem 210.

[0062] Optionally, the valve control status information of the converter valve mainly includes three states: closed, faulty, or operating. That is, the valve control status information is used to indicate to the cooperative control subsystem 210 which state the converter valve is currently in among closed, faulty, and operating. Further, when the converter valve is in a faulty state, the valve control status information of the converter valve is also used to indicate the existing fault of the converter valve to the cooperative control subsystem 210.

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

[0064] In this embodiment, by the converter valve control unit 221 uploading the valve control status information of the converter valve to the cooperative control subsystem 210, the cooperative control subsystem 210 can easily grasp the status of the converter valve in a timely manner, better cooperatively control the operations of the converter valve and the energy storage valve, and ensure the reliability of system control.

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

[0066] Optionally, the plurality of converter valve control units 221 may communicate with each other, exchange control information, and can switch between master and slave with each other. That is, one of the plurality of converter valve control units 221 is a master control unit, while the other converter valve control units 221 are slave control units. When the master control unit fails, one of the slave control units can be set as the master control unit.

[0067] As can be understood, the plurality of converter valve control units 221 may be integrated into different plugins within the same device or provided in different devices. Similarly, the N first power control units 222 may be integrated into different plugins within the same device or provided in different devices. Also, the converter valve control unit 221 may be integrated into a different plugin within the same device as the first power control unit 222 or provided in a different device. The embodiments of the present application do not limit this.

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

[0069] Optionally, in the embodiments of the present application, the energy storage valve includes M energy storage modules, and each energy storage module in the M energy storage modules includes a second power module and a battery module, where M is a positive integer. Further, as shown in FIG. 7, the energy storage valve control subsystem 230 includes 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 according to the commands of the cooperation control subsystem 210, where Q is a positive integer not greater than M. The M second power control units 232 are used to control the activation or deactivation of the M second power modules according to the Q second control commands. The M battery control units 233 are used to respectively control the charge and discharge of the M battery modules in the M energy storage modules.

[0070] Specifically, the energy storage valve includes M energy storage modules. Each of the energy storage modules may be the energy storage module 121 shown in FIG. 3, and each of the energy storage modules includes a second power module and a battery module connected in parallel. That is, the energy storage valve includes M second power modules and M battery modules. In one example, the second power module may be the half-bridge type power module 1211 shown in FIG. 4a. In another example, the second power module may be the full-bridge type power module 1211 shown in FIG. 4b. Optionally, 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. That is, each second power module in the M second power modules corresponds to one second power control unit 232, and each battery module in the M battery modules corresponds to one battery control unit 233, while the M second power control units 232 and the 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 the commands of the cooperation control subsystem 210 and generating control commands for 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, it is responsible for controlling the activation or deactivation of the corresponding second power module.In another example, Q is less than M, that is, only some of the M second power control units 232 receive the control command, and these some second power control units 232 may control the operation of the corresponding second power module according to the received control command. For example, they may control the activation or deactivation of the corresponding second power module. On the other hand, some other second power control units 232 that do not receive the control command may control the corresponding second power module to be in a default state, for example, a default of deactivation state or a default of activation state. Also, each battery control unit 233 in the M battery control units 233 controls the operation of the corresponding battery module and is used, for example, to control the charge and discharge of the corresponding battery module.

[0071] In this embodiment, for the M second power modules and the M battery modules in the energy storage valve, an energy storage valve control unit 231, M second power control units 232 and M battery control units 233 are provided, and the energy storage valve control unit 231 communicates with the cooperative control subsystem 210 as the upper control unit of the M second power control units 232. That is, by adopting a hierarchical design and a modular design for the energy storage valve control subsystem 230, expansion and integration become easy. Also, the converter valve and the energy storage valve are controlled separately. The technology of the converter valve control subsystem 220 is relatively mature, and the energy storage valve control subsystem 230 can be expanded and developed based on the converter valve control subsystem 220, and the realization of engineering is easy.

[0072] Note that the first power module and the second power module may be the same or different. The embodiments of the present application do not limit this.

[0073] Optionally, in the embodiments of the present application, the energy storage valve control unit 231 is also used to generate P third control commands for the M battery modules according to the commands of the cooperative control subsystem 210. P is a positive integer less than or equal to M, and the M battery control units 233 are used to respectively control the charging and discharging of the M battery modules according to the P third control commands.

[0074] In one example, P is equal to M, that is, each battery module corresponds to one control command, each battery control unit 233 corresponds to one control command, and each battery control unit 233 in 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, it is responsible for controlling the charging and discharging of the corresponding battery module. In another example, P is less than M, that is, only some of the M battery control units 233 receive control commands, and these some battery control units 233 may control the operation of the corresponding battery modules according to the received control commands. For example, they control the charging and discharging of the corresponding battery modules. On the other hand, some other battery control units 233 that do not receive control commands may control the corresponding battery modules to be in 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, and the second power control unit 232 and the battery control units 233 control the second power module and the battery modules in parallel, which facilitates the control of the system, thereby improving the control efficiency of the system.

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

[0077] Optionally, 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), current, etc. of the battery module. Optionally, 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 corresponding battery module in response to the request of the energy storage valve control unit 231. That is, according to the state information required by the energy storage valve control unit 231, the battery control unit 233 may upload the required state information.

[0078] In this embodiment, by the battery control unit 233 uploading the state information of the corresponding battery module to the energy storage valve control unit 231, the energy storage valve control unit 231 can timely grasp the state of the battery module and perform corresponding control on the battery module, thereby ensuring the control reliability of the energy storage valve control subsystem 230.

[0079] Optionally, in the embodiment of the present application, the M second power control units 232 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 233 are used to perform charge and discharge control on the M battery modules respectively according to the R fourth control commands.

[0080] That is, the M battery control units 233 do not directly communicate with the energy storage valve control unit 231, but indirectly communicate with the energy storage valve control unit 231 through the M second power control units 232.

[0081] In one example, R is equal to M, that is, each battery module corresponds to one control command, each battery control unit 233 corresponds to one control command, and each battery control unit 233 among 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, it plays a role in controlling the charge and discharge of the corresponding battery module. In another example, R is less than M, that is, 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, it controls the charge and discharge of the corresponding battery module. On the other hand, some other battery control units 233 that do not receive the control command may control the corresponding battery module to be in a default state, for example, a default of not charging or a default of not discharging.

[0082] In this embodiment, the M battery control units 233 are respectively controlled by the M second power control units 232, and the communication load of the energy storage valve control unit 231 can be reduced.

[0083] Optionally, in the embodiment of the present application, each battery control unit 233 among the M battery control units 233 is also used to upload the state information of the corresponding battery module to the corresponding second power control unit 232.

[0084] Similar to the above embodiments, 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), current, etc. of the battery module. Optionally, the state information of the battery module may be a function of 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. That is, according to the information indicated by the fourth control command, the battery control unit 233 may upload the information.

[0085] In this embodiment, by uploading the state information of the battery module corresponding to the battery control unit 233 to the second power control unit 232, the second power control unit 232 can timely feedback the state of the battery module to the energy storage valve control unit 231 and perform corresponding control on the battery module, thereby ensuring the control reliability of the energy storage valve control subsystem 230.

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

[0087] Optionally, the state information of the second power module mainly includes states such as input, output, closing, and failure. That is, the state 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 among input, output, closing, and failure. Further, when the second power module is in a failure state, the state information of the second power module is also used to indicate the existing failure of the corresponding second power module to the energy storage valve control unit 231.

[0088] In this embodiment, the second power control unit 232 uploads the state information of the second power module to the energy storage valve control unit 231, so that the energy storage valve control unit 231 can easily grasp the state of each second power module in a timely manner, and the reliability of system control can be ensured.

[0089] Optionally, in the embodiment of the present application, the energy storage valve control unit 231 is also used to upload the valve control state information of the energy storage valve to the cooperative control subsystem 210.

[0090] Optionally, the valve control state information of the energy storage valve mainly includes three states: closed, faulty, or operating. That is, the valve control state information is used to indicate to the cooperative control subsystem 210 which state the energy storage valve is currently in among closed, faulty, and operating. Further, when the energy storage valve is in a faulty state, the valve control state information of the energy storage valve is also used to indicate the existing fault of the energy storage valve to the cooperative control subsystem 210.

[0091] Optionally, the energy storage valve control unit 231 determines 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 may report the determined valve control state information to the cooperative control subsystem 210.

[0092] In this embodiment, by uploading the valve control state information of the energy storage valve to the cooperative control subsystem 210 by the energy storage valve control unit 231, the cooperative control subsystem 210 can easily grasp the state of the energy storage valve in a timely manner, better coordinate the operations of the converter valve and the energy storage valve, and ensure the reliability of system control.

[0093] Optionally, in the embodiments of the present application, the second power control unit 232 and the battery control unit 233 corresponding to the same energy storage module communicate with each other.

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

[0095] Optionally, the battery data may include all battery parameters such as the voltage, charge amount, temperature, state of charge (SOC), current, etc. of the battery module. Also, the battery data is what the battery control unit 233 spontaneously reports 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 the battery data of the corresponding battery module to the battery monitoring unit.

[0097] In another example, the battery control units 233 are connected by daisy-chain communication, and only the two battery control units 233 at the head and tail of the daisy chain communicate directly with the battery monitoring unit. That is, the two battery control units 233 at the head and tail 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] Optionally, regardless of which example described above is used by the battery monitoring unit to acquire the battery data of the M battery modules, daisy-chain communication may be adopted among the M battery control units 233.

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

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

[0101] As can be understood, the plurality of energy storage valve control units 231 may be integrated into different plugins within the same device, or may be provided in different devices. Similarly, the M second power control units 232 may be integrated into different plugins within the same device, or may be provided in different devices. The M battery control units 233 may be integrated into different plugins within the same device, or may be provided in different devices. Also, the energy storage valve control unit 231, the second power control unit 232, and the battery control unit 233 may be integrated into different plugins within the same device, or may be provided in different devices. The embodiments of the present application do not limit this.

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

[0103] Optionally, in the embodiment of the present application, the cooperative control subsystem 210 includes a plurality of system control units, and each system control unit among the plurality of system control units communicates with both 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] Optionally, the plurality of system control units may communicate with each other, exchange control information, and are capable of switching between master and slave with each other. That is, one of the plurality of system control units is a master control unit, while the other system control units are slave control units, and when the master control unit fails, one of the slave control units can be set as the master control unit.

[0105] As can be understood, the plurality of system control units may be integrated into different plugins within the same device or provided in different devices. The embodiment of the present application does not limit this.

[0106] In this embodiment, the cooperative control subsystem 210 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 220 and the energy storage valve control subsystem 230, thereby meeting the requirements for redundant design of the cooperative control subsystem 210 and ensuring the control reliability of the cooperative control subsystem 210.

[0107] Optionally, 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] Hereinafter, with reference to FIGS. 8 and 9, the control system of the energy storage system according to the embodiments of the present application will be described in detail.

[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. The system control unit A and the system control unit B 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, the system control unit A generates a control command and sends it to the converter valve control unit A and the energy storage valve control unit A. The system control unit B generates a control command and sends it to the converter valve control unit B and the energy storage valve control unit B. The converter valve control unit A and the converter valve control unit B send on / off commands to the first power control units 1 - N according to the control commands generated by the system control unit A and the system control unit B respectively, and the first power control units 1 - N send the states of the controlled first power modules to the converter valve control unit A and the converter valve control unit B.The converter valve control unit A transmits the valve control state of the converter valve to the system control unit A, and the converter valve control unit B transmits the valve control state 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 input and output 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 state 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 and discharge commands to the battery control unit 1-M respectively. The battery control unit 1-M, on the one hand, controls the charge and discharge of the battery module according to the charge and discharge commands and uploads the battery state of the battery module to the second power control unit 1-M. 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. The system control unit A and the system control unit B 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, the system control unit A generates a control command and sends it to the converter valve control unit A and the energy storage valve control unit A. The system control unit B generates a control command and sends it to the converter valve control unit B and the energy storage valve control unit B. The converter valve control unit A and the converter valve control unit B send on / off commands to the first power control units 1-N according to the control commands generated by the system control unit A and the system control unit B respectively, and the first power control units 1-N send the state 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 send on / off commands to the second power control unit 1-M and charge / discharge commands to the battery control unit 1-M according to the control commands generated by the system control unit A and the system control unit B respectively. The second power control unit 1-M sends the state 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 command and sends 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 by daisy chain communication, and the battery data acquired by the battery control unit 1-M is aggregated to the battery monitoring unit. Also, the second power control unit corresponding to the same energy storage module and the battery control unit 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 executed by the cooperative control subsystem described above. As shown in Figure 10, the control method 300 includes the following steps.

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

[0113] Regarding the content included in the control method 300, each step executed by the cooperative control subsystem 210 may be referred to. Optionally, the control method 300 may further include each step executed by the converter valve subsystem 220 and the energy storage valve subsystem 230. For the sake of simplicity, the description thereof is omitted here.

[0114] FIG. 11 is a schematic flowchart of a control method for an energy storage system based on the control structure shown in FIG. 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 the energy storage valve in different control modes through control mode selection, power calculation, power control (AC power / DC power), and internal and external double-loop control (active power / reactive power) in sequence. (2) In the converter valve control subsystem, the converter valve control unit performs bridge arm current control, capacitor voltage equalization control, and modulation, and generates an on / off command 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, and generates an on / off command for the second power module in the energy storage valve. (5) Further, the second power control unit in the energy storage valve control subsystem performs on / off control 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 charging and discharging command generated by the second power control unit, and at the same time, aggregates and calculates the battery information of the battery module.

[0115] For better understanding, in each embodiment of the present application, the magnitude of the numbers of the above processes does not indicate the order of execution. Instead, the execution order of each process should be determined by its function and unique logic, and does not limit the implementation process of the embodiments of the present application.

[0116] The embodiments of the present application further provide a computer-readable storage medium for storing a computer program.

[0117] Optionally, the computer-readable storage medium may be applied to the control system according to the embodiments of the present application, and the computer program causes the computer to execute the corresponding processes realized by the control system in each method of the embodiments of the present application. For the sake of simplicity, the description thereof is omitted here.

[0118] The embodiments of the present application further provide a computer program product including computer program instructions.

[0119] Optionally, the computer program product may be applied to the control system according to the embodiments of the present application, and the computer program instructions cause the computer to execute the corresponding processes realized by the control system in each method of the embodiments of the present application. For the sake of simplicity, the description thereof is omitted here.

[0120] The embodiments of the present application further provide a computer program.

[0121] Optionally, the computer program may be applied to the control system according to the embodiments of the present application. When the computer program is executed on a computer, the computer is caused to execute the corresponding processes realized by the control system in each method of the embodiments of the present application. For the sake of simplicity, the description thereof is omitted here.

[0122] Optionally, embodiments of the present application further provide an energy storage system, which includes a converter valve and an energy storage valve connected to the DC side of the converter valve, and the high-voltage direct-connected energy storage system may further include the control system described in each of the above embodiments.

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

[0124] Furthermore, in the embodiments of the present application, the VSC converter valve adopts a modular multilevel converter (MMC) type structure.

[0125] The above are only embodiments of the present application, and the protection scope of the present application is not limited thereto. Those skilled in the art in this technical field can easily conceive of changes or substitutions within the technical scope described in the present application, and all of them 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. 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 cooperative 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 cooperative 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 cooperative control subsystem. A control system for an energy storage system, characterized in that.

2. 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 according to the commands of the cooperative control subsystem, where K is a positive integer not exceeding 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 according to Claim 1, characterized in that.

3. Each first power control unit in 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. The control system according to Claim 2, characterized in that.

4. The converter valve control unit is also used to upload the valve control state information of the converter valve to the cooperative control subsystem. The control system according to Claim 2 or 3, characterized in that.

5. The energy storage valve includes M energy storage modules, and each energy storage module in the M energy storage modules includes a second power module and a battery module. 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 the M second power modules in the M energy storage modules according to the commands of the coordination control subsystem, where Q is a positive integer not exceeding M. The M second power control units are used to control the connection or disconnection of the M second power modules respectively according to the Q second control commands. The control system according to any one of claims 1 to 4, wherein the M battery control units are used to control the charge and discharge of the M battery modules in the M energy storage modules respectively.

6. The energy storage valve control unit is also used to generate P third control commands for the M battery modules according to the commands of the coordination control subsystem, where P is a positive integer not exceeding M. The M battery control units are used to control the charge and discharge of the M battery modules respectively according to the P third control commands. The control system according to claim 5 is characterized in that.

7. The control system according to claim 6, wherein each battery control unit in the M battery control units is also used to upload the state information of the corresponding battery module to the energy storage valve control unit.

8. 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 not exceeding M. The M battery control units are used to control the charge and discharge of the M battery modules respectively according to the R fourth control commands. The control system according to claim 5 is characterized in that.

9. The control system according to claim 8, wherein each battery control unit among the M battery control units is also used to upload the state information of the corresponding first battery module to the corresponding second power control unit.

10. The control system according to any one of claims 5 to 9, wherein the energy storage valve control unit is also used to upload the valve control state information of the energy storage valve to the cooperative control subsystem.

11. The control system according to any one of claims 5 to 10, wherein each second power control unit among 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.

12. The control system according to any one of claims 5 to 11, wherein the second power control unit corresponding to the same energy storage module and the battery control unit communicate with each other.

13. The energy storage valve control subsystem The control system according to any one of claims 5 to 12, further comprising a battery monitoring unit for acquiring battery data of the M battery modules.

14. The control system according to any one of claims 5 to 13, wherein M is a positive integer greater than 1, and the M battery control units are connected by daisy chain communication.

15. The converter valve control subsystem includes a plurality of converter valve control units. Each converter valve control unit among 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. The control system according to any one of claims 2 to 4.

16. The energy storage valve control subsystem includes a plurality of energy storage valve control units. Each energy storage control unit among 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. The control system according to any one of claims 5 to 14.

17. 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. The control system according to any one of claims 1 to 16, characterized in that.

18. The converter valve control subsystem is integrated with the converter valve, and the energy storage valve control subsystem is integrated with the energy storage valve. The control system according to any one of claims 1 to 17, characterized in that.

19. 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 18, characterized in that.

20. A control method 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 method includes sending a first command for controlling the operation of the converter to the converter valve control subsystem and sending a second command for controlling the operation of the energy storage valve to the energy storage valve control subsystem. A control method for an energy storage system, characterized in that.

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