Large-scale composite energy storage system

Abstract

The invention relates to a large-scale composite energy storage system. The system is characterized in that a grid-connected coupling platform is connected with an alternating-current power grid through a power grid interface unit; the electric energy coupling platform is used for controlling a short-time energy storage unit and a long-time energy storage power unit in the electric energy coupling platform and a long-time energy storage energy unit in the long-time energy platform according to power and energy scheduling requirements; the heat energy coupling platform is used for controlling the temperature and heat energy distribution of the large-scale composite energy storage system; the chemical energy coupling platform optimizes the long-time energy platform according to the control requirement of the long-time energy storage power unit in the electric energy coupling platform so as to realize the balance, recovery and regeneration control of the electrolyte; and the capacity regeneration coupling platform is used for realizing capacity regeneration according to the capacity regeneration requirement of the chemical energy coupling platform. Therefore, through an innovative thought and method of establishing a direct or indirect cross coupling path of three dimensions of electric energy, heat energy and chemical energy, optimal utilization of the electric energy, heat energy and chemical energy can be realized.

Description

Technical Field

[0001] The present disclosure relates to the field of energy storage technology, and in particular, to a large-scale composite energy storage system. Background Art

[0002] The rapid development of new power systems has put forward an urgent need for the development of large-scale energy storage systems at the 100-megawatt level. The current 100-megawatt energy storage systems are mainly divided into short-term energy storage systems represented by lithium-ion batteries and long-term energy storage systems represented by all-vanadium liquid flow batteries. However, the two types of energy storage systems use different system solutions, system architectures and control methods, which hinders the development of large-scale energy storage. Summary of the invention

[0003] The purpose of the present disclosure is to provide a large-scale composite energy storage system, so as to better realize the complementary integration of short-term energy storage and long-term energy storage by establishing innovative ideas and methods of direct or indirect cross-coupling paths in the three dimensions of electrical energy, thermal energy and chemical energy.

[0004] In order to achieve the above objectives, the present disclosure provides a large-scale composite energy storage system, comprising:

[0005] A grid-connected coupling platform, connected to the AC grid via a grid interface unit, for providing an energy interface for the large-scale composite energy storage system to achieve energy management control and grid status monitoring functions;

[0006] An electric energy coupling platform, used to control the short-term energy storage unit, the long-term energy storage power unit, and the long-term energy storage energy unit in the electric energy coupling platform according to the power and energy scheduling requirements, so as to realize the power coupling conversion and energy flow control of the large-scale composite energy storage system, wherein the scheduling requirements are determined based on the monitoring status of the power grid;

[0007] A thermal energy coupling platform, used to control the temperature change and thermal energy distribution of the large-scale composite energy storage system according to the thermal management distribution characteristics of short-term energy storage and the thermal management distribution characteristics of long-term energy storage;

[0008] A chemical energy coupling platform, which is used to optimize the long-term energy platform according to the control requirements of the long-term energy storage power unit in the electrical energy coupling platform to achieve balance, recovery and regeneration control of the electrolyte;

[0009] The capacity regeneration coupling platform is used to achieve capacity regeneration by coupling the grid-connected coupling platform according to the capacity regeneration requirement of the chemical energy coupling platform.

[0010] Optionally, the grid-connected coupling platform includes a three-phase first subsystem, each phase of the first subsystem includes N series-connected cascaded DC-AC converters, and the three-phase common ground side is connected to the capacity regeneration coupling platform;

[0011] The cascaded DC-AC converter is used to convert the energy provided by the AC power grid into DC power and input the DC power into the power coupling platform, or to convert the DC power of the power coupling platform into AC power and input the energy into the AC power grid;

[0012] The grid-connected coupling platform is also used to convert the energy provided by the AC power grid into AC power of a target voltage, and input the AC power of the target voltage into the capacity regeneration coupling platform.

[0013] Optionally, the power coupling platform includes a three-phase second subsystem, each phase of the second subsystem includes M power coupling modules, each of the power coupling modules includes a short-time energy storage unit, a long-time energy storage power unit, a bidirectional DC-DC isolation unit, a short-time heat dissipation unit, a chemical energy power supply unit, a DC power interface terminal, a short-time thermal energy interface terminal, a long-time thermal energy interface terminal and a long-time chemical energy interface terminal;

[0014] The DC power interface is connected to the short-time energy storage unit and the grid-connected coupling platform, and is connected to the long-time energy storage power unit through the bidirectional DC-DC isolation unit;

[0015] The short-time thermal energy interface end is connected to the short-time energy storage unit through the short-time heat dissipation unit, and is connected to a first target device for thermal management, wherein the first target device for thermal management includes at least one of an independent heat dissipation unit and a short-time unit thermal energy interface end of another electric energy coupling module;

[0016] The long-term thermal energy interface terminal is connected to the long-term energy storage power unit and the thermal management second target device, wherein the thermal management second target device includes at least one of the long-term unit thermal energy interface terminals of the independent heat dissipation unit and other power coupling modules;

[0017] The chemical energy power supply unit connects the short-term energy storage unit to the chemical energy coupling platform via the long-term chemical energy interface.

[0018] Optionally, the first thermal management target device and the second thermal management target device are determined according to the optimization target of the heat dissipation system corresponding to the large-scale composite energy storage system, and the optimization target is used to achieve coupling between short-time thermal management units, between long-time thermal management units, or between the short-time thermal management unit and the long-time thermal management unit with the minimum heat energy loss of the system as the target.

[0019] Optionally, the long-term energy storage power unit is used to realize the bidirectional conversion of chemical energy and electrical energy in the long-term energy storage pipeline according to the long-term energy storage energy management target, wherein the energy conversion mode of the long-term energy storage chemical energy and electrical energy is determined based on the long-term energy storage pipeline system corresponding to the large-scale composite energy storage system, and the energy conversion optimization process of the long-term energy storage chemical energy and electrical energy includes the long-term energy storage power unit self-drive optimization and the long-term energy storage power unit coupling drive optimization with other electrical energy coupling modules.

[0020] Optionally, the thermal energy coupling platform includes a three-phase third subsystem, each phase of the third subsystem includes O thermal energy coupling modules, and each of the thermal energy coupling modules includes a short-time thermal energy management unit, a long-time thermal energy management unit and a thermal coupling heat dissipation unit;

[0021] The short-term thermal energy management unit is connected to the short-term thermal energy interface terminal of the power coupling platform;

[0022] The long-term thermal energy management unit is connected to the long-term thermal energy interface terminal of the power coupling platform;

[0023] The thermal coupling heat dissipation unit is connected to the short-term thermal energy management unit and the long-term thermal energy management unit, and the thermal coupling heat dissipation unit includes a heat storage unit.

[0024] Optionally, the chemical energy coupling platform includes a three-phase fourth subsystem, each phase of the fourth subsystem includes P chemical energy coupling modules, and each of the chemical energy coupling modules includes an electrolyte flow driving unit, an online capacity balancing unit, an online capacity repair unit and an online capacity regeneration management unit;

[0025] The electrolyte flow driving unit is connected to the chemical energy power supply unit and the long-term energy storage power unit of the power coupling platform, and is used to drive the electrolyte to circulate in a plurality of the long-term energy storage power units according to the charging and discharging requirements of the long-term energy storage power units, wherein the electrolyte flow driving unit and the long-term energy storage power units are connected via an electrolyte pipeline;

[0026] The online capacity balancing unit is connected to the electrolyte flow driving unit and is connected to a plurality of long-term energy storage units of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to drive the capacity balance distribution of the electrolyte in the plurality of long-term energy storage units according to the capacity balance requirements of the long-term energy platform;

[0027] The online capacity repair unit is connected to the electrolyte flow driving unit and is connected to a plurality of long-term energy storage units of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to drive the capacity repair distribution of the electrolyte in the plurality of long-term energy storage units according to the capacity repair requirements of the long-term energy platform;

[0028] The online capacity regeneration management unit is connected to the electrolyte flow driving unit and the capacity regeneration coupling platform, and is connected to multiple long-term energy storage units of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to drive the capacity regeneration distribution of the electrolyte in the multiple long-term energy storage units according to the capacity regeneration requirements of the long-term energy platform.

[0029] Optionally, the chemical energy coupling platform further includes a short-time energy storage safety management module, which is connected to the short-time energy storage unit of the electrical energy coupling platform and is used to control the capacity of the short-time energy storage unit according to safety operation requirements.

[0030] Optionally, the long-term energy platform includes a three-phase fifth subsystem, each phase of the fifth subsystem includes Q long-term energy storage energy units, and the long-term energy storage energy unit includes a positive electrode tank and a negative electrode tank;

[0031] The long-term energy storage energy unit is connected to the long-term energy storage power unit of the electrical energy coupling platform through the chemical energy coupling platform to achieve online capacity balancing and online capacity repair;

[0032] The long-term energy storage unit is also connected to the capacity regeneration coupling platform via the chemical energy coupling platform to achieve online capacity regeneration.

[0033] Optionally, the long-term energy platform is also used to couple the thermal coupling heat dissipation unit, the short-term thermal energy management unit or the long-term thermal energy management unit in the thermal energy coupling platform according to temperature control and thermal energy distribution requirements to perform optimized regulation and energy distribution.

[0034] Optionally, the capacity regeneration coupling platform includes R three-phase parallel AC-DC converters and a long-time energy storage capacity regeneration unit corresponding to each of the AC-DC converters, wherein the AC-DC converter is connected to the three-phase common ground side of the grid-connected coupling platform; the long-time energy storage capacity regeneration unit includes a regenerative anode tank, a regenerative cathode tank and a regenerative power management unit for realizing electrolysis;

[0035] The long-term energy storage capacity regeneration unit is connected to the online capacity regeneration management unit of the chemical energy coupling platform, and is connected to the positive electrode tank and the negative electrode tank of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to introduce the electrolyte that needs to be regenerated in the long-term energy storage unit into the regeneration anode tank or the regeneration cathode tank of the long-term energy storage capacity regeneration unit when in the regeneration mode; and after adding the regeneration material, electrolysis is carried out through the AC-DC converter to complete the regeneration process of the electrolyte. After the regeneration is completed, the electrolyte is controlled by the online capacity regeneration management unit to flow from the regeneration anode tank and the regeneration cathode tank to the positive electrode tank and the negative electrode tank respectively, so as to realize the system capacity regeneration distribution.

[0036] Optionally, the long-term energy storage capacity regeneration unit is also used to control the AC end of the AC-DC converter to maintain a zero voltage point, the DC end to maintain an operating reference voltage in the electrolytic cell, and the regeneration anode tank and the regeneration cathode tank to remain in an active standby state when not in regeneration mode.

[0037] Optionally, the large-scale composite energy storage system further includes a controller, and the controller is used to:

[0038] Controlling the large-scale composite energy storage system to perform self-test, wherein the self-test includes periodic fault self-test, non-periodic fault self-test, capacity self-test and temperature condition self-test, and the non-periodic fault self-test is performed when a target parameter in the large-scale composite energy storage system reaches a corresponding reference threshold;

[0039] If the self-check passes, determining the power and energy dispatching requirements of the AC power grid;

[0040] According to the scheduling requirements, starting the corresponding platforms in the large-scale composite energy storage system in sequence;

[0041] After the grid-connected coupling platform is started, the target operation mode is started according to the monitoring status of the power grid.

[0042] Optionally, the controller is further configured to:

[0043] If the periodic fault self-test result or the non-periodic fault self-test result is abnormal, the fault point is isolated or removed.

[0044] Optionally, the controller is further configured to:

[0045] If there is no abnormality in the periodic fault self-test result and the non-periodic fault self-test result, the capacity self-test is performed.

[0046] Optionally, the controller is further configured to:

[0047] If the capacity self-test result is abnormal, the large-scale composite energy storage system is controlled to perform online capacity balancing, repair or capacity regeneration;

[0048] If the capacity self-test result is normal, the temperature condition self-test is performed.

[0049] Optionally, the controller is further configured to:

[0050] If the temperature condition self-test result is abnormal, controlling the thermal energy coupling platform to start;

[0051] If the temperature condition self-check result is normal, the scheduling requirement is determined.

[0052] Optionally, the controller is used to start corresponding platforms in the large-scale composite energy storage system in sequence according to the scheduling requirements in the following manner:

[0053] If the dispatching demand has a long-term energy demand, the long-term energy storage power unit of the electric energy coupling platform, the electrolyte flow drive unit of the chemical energy coupling platform, the long-term energy platform, and the grid-connected coupling platform are controlled to start in sequence;

[0054] If the dispatching demand has a short-term energy demand, the short-term energy storage unit of the electric energy coupling platform and the grid-connected coupling platform are controlled to start in sequence.

[0055] Optionally, the grid monitoring status is determined based on grid impedance.

[0056] Optionally, the target operation mode includes a grid-following structure and parameters in a grid-connected mode, a grid-building structure and parameters in a grid-connected mode, or a grid-building structure and parameters in an off-grid mode.

[0057] In the above technical scheme, the grid-connected coupling platform is connected to the AC grid through the grid interface unit, and is used to provide an energy interface for the large-scale composite energy storage system to realize energy management control and grid status monitoring functions; the electric energy coupling platform is used to control the short-term energy storage unit, the long-term energy storage power unit, and the long-term energy storage energy unit in the long-term energy platform according to the scheduling requirements of power and energy, so as to realize power coupling conversion and energy flow control of the large-scale composite energy storage system, wherein the scheduling requirements are determined based on the grid monitoring status; the thermal energy coupling platform is used to control the temperature change and thermal energy distribution of the large-scale composite energy storage system according to the thermal management distribution characteristics of the short-term energy storage and the thermal management distribution characteristics of the long-term energy storage; the chemical energy coupling platform is used to optimize the long-term energy platform according to the control requirements of the long-term energy storage power unit in the electric energy coupling platform, so as to realize the balance, recovery and regeneration control of the electrolyte; the capacity regeneration coupling platform is used to realize capacity regeneration by coupling the grid-connected coupling platform according to the capacity regeneration requirements of the chemical energy coupling platform. In this way, by establishing innovative ideas and methods for direct or indirect cross-coupling paths in the three dimensions of electrical energy, thermal energy and chemical energy, we can give full play to the complementary fusion characteristics of short-term energy storage and long-term energy storage, optimize the energy and power distribution between short-term energy storage and long-term energy storage, and achieve optimal utilization of electrical energy, thermal energy and chemical energy; realize online repair and regeneration of coupling modules, reduce energy and material losses of coupling modules, provide active support capabilities for networking of hybrid energy storage modes, and thus improve the long-term, reliability and safety of large-scale composite energy storage systems.

[0058] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0060] Figure 1 It is a schematic diagram of an energy storage system in the related art.

[0061] Figure 2 It is a block diagram of a large-scale composite energy storage system provided by an exemplary embodiment of the present disclosure.

[0062] Figure 3 It is a schematic diagram of a large-scale composite energy storage system provided by an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0063] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0064] The current 100-megawatt energy storage system is mainly divided into short-term energy storage systems represented by lithium-ion batteries and long-term energy storage systems represented by all-vanadium liquid flow batteries, such as Figure 1 As shown, the two types of energy storage systems use different system solutions, system architectures and control methods, and have not been able to overcome their respective shortcomings through coupling complementary effects. For example, lithium batteries have a high potential safety risk and flow batteries have a high cost, which hinders the development of large-scale energy storage. In order to solve the above problems and better expand the scale of energy storage, the present disclosure provides a large-scale composite energy storage system, which achieves the complementary integration of short-term energy storage and long-term energy storage by establishing innovative ideas and methods for direct or indirect cross-coupling paths in the three dimensions of electrical energy, thermal energy and chemical energy.

[0065] In the description below, words such as “first” and “second” are only used for the purpose of distinguishing the description and should not be understood as indicating or implying relative importance or order.

[0066] Figure 2 is a block diagram of a large-scale composite energy storage system provided by an exemplary embodiment of the present disclosure. Figure 2 As shown, the large-scale composite energy storage system includes a grid-connected coupling platform 10, a grid interface unit 11, an electric energy coupling platform 12, a thermal energy coupling platform 13, a chemical energy coupling platform 14, a long-time energy platform 15 and a capacity regeneration coupling platform 16.

[0067] The grid-connected coupling platform 10 is connected to the AC grid via the grid interface unit 11, and is used to provide an energy interface for the large-scale composite energy storage system to realize energy management control and grid status monitoring functions;

[0068] The electric energy coupling platform 12 is used to control the short-term energy storage unit 121, the long-term energy storage power unit 122, and the long-term energy storage energy unit in the long-term energy platform 15 according to the power and energy scheduling requirements, so as to realize the power coupling conversion and energy flow control of the large-scale composite energy storage system, wherein the scheduling requirements are determined based on the monitoring status of the power grid;

[0069] The thermal energy coupling platform 13 is used to control the temperature change and thermal energy distribution of the large-scale composite energy storage system according to the thermal management distribution characteristics of the short-term energy storage and the thermal management distribution characteristics of the long-term energy storage;

[0070] The chemical energy coupling platform 14 is used to optimize the long-term energy platform 15 according to the control requirements of the long-term energy storage power unit 122 in the electrical energy coupling platform 12, so as to achieve the balance, recovery and regeneration control of the electrolyte;

[0071] The capacity regeneration coupling platform 16 is used to achieve capacity regeneration by coupling with the grid-connected coupling platform 10 according to the capacity regeneration requirement of the chemical energy coupling platform 14 .

[0072] For example, the AC power grid can be a power grid for renewable energy generation, such as a wind power grid. The power and energy dispatching requirements of the power grid can be issued by the power grid dispatching station, and determined by the controller of the large-scale composite energy storage system, that is, the controller of the energy management system (EMS), or can be determined by the large-scale composite energy storage system EMS according to the operating status. That is, the EMS can both autonomously generate power and energy dispatching requirements and receive power and energy dispatching requirements issued by the upper computer of the power grid dispatching station.

[0073] The scheduling requirements of power and energy may include long-term energy requirements and / or short-term energy requirements. If there is a long-term energy requirement in the scheduling requirements of power and energy, the long-term energy storage power unit 122 of the electric energy coupling platform 12 and the long-term energy storage energy unit in the long-term energy platform 15 can be controlled to act. If there is a short-term energy requirement in the scheduling requirements of power and energy, the short-term energy storage unit 121 of the electric energy coupling platform 12 can be controlled to act. The chemical energy coupling platform 14 can optimize the long-term energy platform 15 according to the control requirements of the long-term energy storage power unit 122 in the electric energy coupling platform 12. The chemical energy coupling platform 14 can control the electrolyte flow state (such as flow rate) of the positive electrode tank and the negative electrode tank in the long-term energy platform 15, so that the long-term energy storage power unit 122 in the electric energy coupling platform 12 can operate normally, and realize the balance, recovery and regeneration control of the electrolyte.

[0074] The thermal management distribution characteristics refer to the distribution state of heat at the current moment. The thermal management distribution characteristics of short-term energy storage and long-term energy storage can be combined through the thermal energy coupling platform 13. The distributed flow characteristics of short-term energy storage liquid cooling and long-term energy storage electrolyte can be brought into play, and the thermal management requirements under different modes such as refrigeration and heat dissipation and heating startup can be combined to improve the comprehensive thermal management efficiency of the large-scale composite energy storage system.

[0075] By setting up the capacity regeneration coupling platform 16, capacity regeneration can be achieved by coupling the grid-connected coupling platform 10 according to the capacity regeneration requirements of the chemical energy coupling platform 14, so as to reduce the energy and material loss of the coupling module, provide active support capability for networking of the hybrid energy storage mode, and improve the long-term, reliability and safety of the large-scale composite energy storage system.

[0076] In the above technical scheme, the grid-connected coupling platform is connected to the AC grid through the grid interface unit, and is used to provide an energy interface for the large-scale composite energy storage system to realize energy management control and grid status monitoring functions; the electric energy coupling platform is used to control the short-term energy storage unit, the long-term energy storage power unit, and the long-term energy storage energy unit in the long-term energy platform according to the scheduling requirements of power and energy, so as to realize power coupling conversion and energy flow control of the large-scale composite energy storage system, wherein the scheduling requirements are determined based on the grid monitoring status; the thermal energy coupling platform is used to control the temperature change and thermal energy distribution of the large-scale composite energy storage system according to the thermal management distribution characteristics of the short-term energy storage and the thermal management distribution characteristics of the long-term energy storage; the chemical energy coupling platform is used to optimize the long-term energy platform according to the control requirements of the long-term energy storage power unit in the electric energy coupling platform, so as to realize the balance, recovery and regeneration control of the electrolyte; the capacity regeneration coupling platform is used to realize capacity regeneration by coupling the grid-connected coupling platform according to the capacity regeneration requirements of the chemical energy coupling platform. In this way, by establishing innovative ideas and methods for direct or indirect cross-coupling paths in the three dimensions of electrical energy, thermal energy and chemical energy, we can give full play to the complementary fusion characteristics of short-term energy storage and long-term energy storage, optimize the energy and power distribution between short-term energy storage and long-term energy storage, and achieve optimal utilization of electrical energy, thermal energy and chemical energy; realize online repair and regeneration of coupling modules, reduce energy and material losses of coupling modules, provide active support capabilities for networking of hybrid energy storage modes, and thus improve the long-term, reliability and safety of large-scale composite energy storage systems.

[0077] In an optional embodiment, if Figure 3 As shown, the grid-connected coupling platform 10 may include a three-phase first subsystem, each phase first subsystem includes N series-connected cascaded DC-AC converters, and the three-phase common ground side is connected to the capacity regeneration coupling platform 16;

[0078] The cascaded DC-AC converter is used to convert the energy provided by the AC power grid into DC power and input the DC power to the power coupling platform 12, or convert the DC power of the power coupling platform 12 into AC power and input the energy to the AC power grid;

[0079] The grid-connected coupling platform 10 is also used to convert the energy provided by the AC power grid into AC power of a target voltage, and input the AC power of the target voltage into the capacity regeneration coupling platform 16 .

[0080] Among them, the three-phase common ground side is connected to the three-phase AC-DC converter 161 of the capacity regeneration coupling platform 16. N can be a positive integer. The DC side of the first subsystem is connected to the DC end of the power coupling platform 12, and the AC side is connected in series to form a low-voltage end and a high-voltage end. The high-voltage end is connected to the grid interface unit 11, and the low-voltage end is connected to the capacity regeneration coupling platform 16, that is, the AC power of the target voltage is low-voltage AC power. The state of the DC-AC converter can be based on the independent control of the high-frequency PWM (Pulse Width Modulation) switching frequency, or it can be based on the cascaded H-bridge joint control of the low-frequency switching frequency, so that the system efficiency can be improved.

[0081] In an optional embodiment, if Figure 3 As shown, the power coupling platform 12 may include a three-phase second subsystem, each phase second subsystem includes M power coupling modules, each power coupling module includes a short-time energy storage unit 121, a long-time energy storage power unit 122, a bidirectional DC-DC isolation unit 123, a short-time heat dissipation unit 124, a chemical energy power supply unit 125, a DC power interface terminal, a short-time thermal energy interface terminal, a long-time thermal energy interface terminal and a long-time chemical energy interface terminal;

[0082] The DC power interface terminal is connected to the short-time energy storage unit 121 and the grid-connected coupling platform 10, and is connected to the long-time energy storage power unit 122 through the bidirectional DC-DC isolation unit 123;

[0083] The short-time thermal energy interface end is connected to the short-time energy storage unit 121 through the short-time heat dissipation unit 124, and is connected to the first target device for thermal management, wherein the first target device for thermal management includes at least one of the short-time unit thermal energy interface ends of the independent heat dissipation unit and other power coupling modules;

[0084] The long-term thermal energy interface terminal is connected to the long-term energy storage power unit 122 and the thermal management second target device, wherein the thermal management second target device includes at least one of the independent heat dissipation unit and the long-term unit thermal energy interface terminal of other power coupling modules;

[0085] The chemical energy power supply unit 125 connects the short-term energy storage unit 121 to the chemical energy coupling platform 14 via the long-term chemical energy interface.

[0086] Wherein, M can be a positive integer, and each phase second subsystem can include the same number of power coupling modules. Based on the structure of the power coupling platform 12, the large-scale composite energy storage system can effectively utilize the characteristics of organic and flexible combination of high-voltage isolation and non-isolated power conversion in different links in terms of power conversion, based on the complementary principle of non-isolated design for short-term energy storage and isolated design for long-term energy storage, and give full play to the potential for improving the comprehensive efficiency of power conversion.

[0087] For example, the DC power interface terminal is internally connected to the DC terminal of the short-time energy storage unit 121 inside the power coupling module, and is connected to the DC terminal of the long-time energy storage power unit 122 through a bidirectional DC-DC isolation unit 123; the DC power interface terminal is externally connected to the DC terminal of the grid-connected coupling platform 10. The short-time thermal energy interface terminal can be connected to the short-time energy storage unit 121 through the short-time heat dissipation unit 124, and can be independently cooled or connected to the short-time thermal energy interface terminal of other power coupling modules according to the structural design of the heat dissipation system; the long-time thermal energy interface terminal can connect the long-time thermal energy management unit 132 of the thermal energy coupling platform 13 to the long-time energy storage power unit 122, and can be independently cooled or connected to the long-time thermal energy interface terminal of other power coupling modules according to the structural design of the heat dissipation system; the long-time chemical energy interface terminal can be connected to the chemical energy power supply unit 125, and can be independently controlled by the chemical energy pipeline drive through the structural design of the pipeline system or coupled to the chemical energy pipeline of the long-time power module of other power coupling modules.

[0088] In an optional embodiment, the first target device for thermal management and the second target device for thermal management are determined based on the optimization target of the heat dissipation system corresponding to the large-scale composite energy storage system. The optimization target is used to achieve coupling between short-term thermal management units 131, between long-term thermal management units 132, or between short-term thermal management units 131 and long-term thermal management units 132 with the minimum heat energy loss of the system as the target.

[0089] Each part of the large-scale composite energy storage system has different demands for thermal energy. By setting the optimization target, the excess heat in part A of the large-scale composite energy storage system can be transferred to part B that needs thermal energy, so as to reduce the overall thermal energy loss of the large-scale composite energy storage system.

[0090] In an optional embodiment, the long-term energy storage power unit 122 is used to realize the bidirectional conversion of chemical energy and electrical energy in the long-term energy storage pipeline according to the long-term energy storage energy management target, wherein the energy conversion method of the long-term energy storage chemical energy and electrical energy is determined based on the long-term energy storage pipeline system corresponding to the large-scale composite energy storage system, and the energy conversion optimization process of the long-term energy storage chemical energy and electrical energy includes the long-term energy storage power unit 122 self-drive optimization and the long-term energy storage power unit 122 coupling drive optimization with other electrical energy coupling modules.

[0091] For example, the long-term energy storage energy management target may be determined based on the detected state of the power grid.

[0092] In an optional embodiment, if Figure 3 As shown, the thermal energy coupling platform 13 may include a three-phase third subsystem, each phase third subsystem includes O thermal energy coupling modules, and each thermal energy coupling module includes a short-time thermal energy management unit 131, a long-time thermal energy management unit 132 and a thermal coupling heat dissipation unit 133;

[0093] The short-time thermal energy management unit 131 is connected to the short-time thermal energy interface terminal of the power coupling platform 12;

[0094] The long-term thermal energy management unit 132 is connected to the long-term thermal energy interface terminal of the power coupling platform 12;

[0095] The thermal coupling heat dissipation unit 133 is connected to the short-term thermal energy management unit 131 and the long-term thermal energy management unit 132 , and the thermal coupling heat dissipation unit 133 includes a heat storage unit.

[0096] Wherein, O can be a positive integer, and each phase second subsystem can include the same number of thermal energy coupling modules. The short-term thermal energy management unit 131 and the long-term thermal energy management unit 132 can choose to dissipate heat independently or be coupled with the heat storage unit for heat dissipation.

[0097] In this way, in terms of heat dissipation management of large-scale composite energy storage systems, the thermal management distribution characteristics of short-term energy storage in high-rate mode can be combined with the thermal management distribution characteristics of long-term energy storage in low-rate mode, giving full play to the distributed flow characteristics of short-term energy storage liquid cooling and long-term energy storage electrolyte. By appropriately introducing heat storage technology, the thermal management requirements under different modes such as refrigeration and heat dissipation and heating startup can be combined to improve the comprehensive thermal management efficiency of the composite energy storage system.

[0098] In an optional embodiment, if Figure 3 As shown, the chemical energy coupling platform 14 includes a three-phase fourth subsystem, each phase fourth subsystem includes P chemical energy coupling modules, each chemical energy coupling module includes an electrolyte flow driving unit 141, an online capacity balancing unit 142, an online capacity repair unit 143 and an online capacity regeneration management unit 144;

[0099] An electrolyte flow driving unit 141 is connected to the chemical energy power supply unit 125 and the long-term energy storage power unit 122 of the power coupling platform 12, and is used to drive the electrolyte to circulate in multiple long-term energy storage power units 122 according to the charging and discharging requirements of the long-term energy storage power unit 122, wherein the electrolyte flow driving unit 141 and the long-term energy storage power unit 122 are connected through an electrolyte pipeline;

[0100] The online capacity balancing unit 142 is connected to the electrolyte flow driving unit 141, and is connected to a plurality of long-term energy storage units of the long-term energy platform 15 through the distribution of the electrolyte pipeline, and is used to drive the capacity balance distribution of the electrolyte in the plurality of long-term energy storage units according to the capacity balance requirements of the long-term energy platform 15;

[0101] The online capacity repair unit 143 is connected to the electrolyte flow driving unit 141, and is connected to a plurality of long-term energy storage energy units of the long-term energy platform 15 through the distribution of the electrolyte pipeline, and is used to drive the capacity repair distribution of the electrolyte in the plurality of long-term energy storage energy units according to the capacity repair requirements of the long-term energy platform 15;

[0102] The online capacity regeneration management unit 144 is connected to the electrolyte flow driving unit 141 and the capacity regeneration coupling platform 16, and is connected to multiple long-term energy storage units of the long-term energy platform 15 through the distribution of electrolyte pipelines. It is used to drive the capacity regeneration distribution of the electrolyte in multiple long-term energy storage units according to the capacity regeneration requirements of the long-term energy platform 15.

[0103] Wherein, P may be a positive integer, each phase fourth subsystem may include the same number of chemical energy coupling modules, and the charging and discharging requirements may be confirmed and issued by an energy management system (EMS).

[0104] In an optional embodiment, the chemical energy coupling platform 14 further includes a short-term energy storage safety management module, which is connected to the short-term energy storage unit 121 of the electrical energy coupling platform 12, and is used to control the capacity of the short-term energy storage unit 121 according to the safety operation requirements. The safety operation requirements can be confirmed and issued by the energy management system (EMS).

[0105] In this way, in terms of chemical energy management of large-scale composite energy storage systems, the capacity imbalance change law of short-term energy storage in high-rate mode can be combined with the capacity imbalance change law of long-term energy storage in low-rate mode, giving play to the different optimization characteristics of strong power coupling between short-term energy storage modules and strong energy coupling between long-term energy storage modules, appropriately introducing capacity regeneration units containing regenerative materials, optimizing the online capacity balancing capability of the entire composite energy storage system, improving the online capacity repair level, and ultimately realizing long-term online capacity regeneration of the composite energy storage system, improving the long-life safety and maintenance-free level of the composite energy storage system.

[0106] In an optional embodiment, if Figure 3 As shown, the long-term energy platform 15 may include a three-phase fifth subsystem, each phase of the fifth subsystem includes Q long-term energy storage energy units, and the long-term energy storage energy unit includes a positive electrode tank and a negative electrode tank;

[0107] The long-term energy storage energy unit is connected to the long-term energy storage power unit 122 of the electric energy coupling platform 12 through the chemical energy coupling platform 14 to achieve online capacity balancing and online capacity repair;

[0108] The long-term energy storage unit is also connected to the capacity regeneration coupling platform 16 via the chemical energy coupling platform 14 to achieve online capacity regeneration.

[0109] For example, Q can be a positive integer, and each phase fifth subsystem can include the same number of long-term energy storage energy units. The long-term energy storage energy unit can be connected to the long-term energy storage power unit 122 of the electric energy coupling platform 12 through the chemical energy coupling platform 14, can be expanded according to the energy storage duration, and can be completely decoupled from other long-term energy storage power units 122. The long-term energy storage energy unit can participate in achieving online capacity balancing, online capacity repair and online capacity regeneration through the connection of the chemical energy coupling platform 14, the long-term energy storage power unit 122 of the electric energy coupling platform 12 and the capacity regeneration coupling platform 16.

[0110] In an optional embodiment, the long-term energy module is also used to couple the thermal coupling heat dissipation unit 133, the short-term thermal energy management unit 131 or the long-term thermal energy management unit 132 in the thermal energy coupling platform 13 according to the temperature and thermal energy distribution control requirements to perform optimized regulation and energy distribution.

[0111] In this way, the coupling of the system can be further improved, and the comprehensive thermal management efficiency of the composite energy storage system can be improved.

[0112] In an optional embodiment, if Figure 3 As shown, the capacity regeneration coupling platform 16 may include R three-phase parallel AC-DC converters 161, and a long-time energy storage capacity regeneration unit 162 corresponding to each of the AC-DC converters 161, wherein the AC-DC converter 161 is connected to the three-phase common ground side of the grid-connected coupling platform 10; the long-time energy storage capacity regeneration unit 162 includes a regenerative anode tank, a regenerative cathode tank and a regenerative power management unit for realizing electrolysis.

[0113] The long-term energy storage capacity regeneration unit 162 is connected to the online capacity regeneration management unit 144 of the chemical energy coupling platform 14, and is connected to the positive electrode tank and the negative electrode tank of the long-term energy platform 15 through the distribution of the electrolyte pipeline, and is used to introduce the electrolyte that needs to be regenerated in the long-term energy storage unit into the regeneration anode tank or the regeneration cathode tank of the long-term energy storage capacity regeneration unit 162 when it is in the regeneration mode; and after adding the regeneration material, it is electrolyzed through the AC-DC converter 161 to complete the regeneration process of the electrolyte. After the regeneration is completed, the electrolyte is controlled by the online capacity regeneration management unit 144 to flow from the regeneration anode tank and the regeneration cathode tank to the positive electrode tank and the negative electrode tank respectively, so as to realize the system capacity regeneration distribution.

[0114] The structure of the regeneration power management unit is similar to the long-term energy storage power unit 122 of the power coupling platform 12 , and the two can be the same type of unit or different types of units, which is not limited here. The regeneration power management unit can be connected to the online capacity regeneration management unit 144 .

[0115] In an optional embodiment, the long-term energy storage capacity regeneration unit 162 is also used to control the AC end of the AC-DC converter 161 to maintain a zero voltage point, the DC end to maintain the operating reference voltage in the electrolytic cell, and the regenerated anode tank and the regenerated cathode tank to remain in an active standby state when not in the regeneration mode.

[0116] For example, it can be determined whether the capacity regeneration coupling platform 16 is in the regeneration mode based on the capacity self-test result. If the value of the capacity self-test result is greater than the preset threshold value, it can be determined that the capacity of the long-term energy storage device has a relatively serious capacity problem and the problem can be solved by capacity regeneration. At this time, the capacity regeneration coupling platform 16 can be placed in the regeneration mode to achieve capacity regeneration; if the value of the capacity self-test result is less than the preset threshold value, it can be determined that the capacity problem of the long-term energy storage device is not serious and the problem can be solved by capacity balancing or capacity repair. At this time, the capacity regeneration coupling platform 16 can be temporarily not entered into the regeneration mode to reduce the energy consumption of the system. The AC end of the AC-DC converter 161 is controlled to maintain a zero voltage point, the DC end is maintained at the operating reference voltage in the electrolytic cell, and the regeneration anode tank and the regeneration cathode tank are maintained in an active standby state. When the capacity regeneration coupling platform 16 enters the regeneration mode, the capacity regeneration can be quickly started.

[0117] In an optional embodiment, the large-scale composite energy storage system provided by the present disclosure may further include a controller, which may be used to:

[0118] Control the large-scale composite energy storage system to conduct self-inspection;

[0119] If the self-test passes, the power and energy dispatching requirements of the AC power grid are determined;

[0120] According to the dispatching requirements, the corresponding platforms in the large-scale composite energy storage system are started in sequence;

[0121] After the grid-connected coupling platform is started, the target operation mode is started according to the grid monitoring status.

[0122] Among them, self-check includes periodic fault self-check, non-periodic fault self-check, capacity self-check and temperature condition self-check. Non-periodic fault self-check is performed when the target parameter of the large-scale composite energy storage system reaches the corresponding reference threshold. The target parameter can be the relevant data of the pre-set monitoring point, and the corresponding parameter threshold can be pre-set according to actual needs.

[0123] For example, the periodic detection may include periodic detection in two time scale ranges. The large time scale period is at least one protection cycle period, and the cycle duration is determined according to the protection requirements, generally in the range of milliseconds to seconds. The small time scale period is at least one control cycle period, and the cycle duration is determined according to the control requirements, generally in the range of microseconds to milliseconds. In addition, for time-sensitive critical protection and control, non-periodic interrupts can be set to reduce response delays.

[0124] In an optional embodiment, the controller may also be used to:

[0125] If the periodic fault self-test result or the non-periodic fault self-test result is abnormal, the fault point is isolated or removed;

[0126] If the periodic fault self-test results and the non-periodic fault self-test results are normal, perform a capacity self-test.

[0127] In this way, performing fault self-check on the large-scale composite energy storage system provided by the present disclosure can improve the safety and reliability of system operation, and when there are abnormal monitoring points, the abnormal parts can be processed in a timely manner to avoid affecting the overall operation of the system.

[0128] In an optional embodiment, the controller may also be used to:

[0129] If the capacity self-test result is abnormal, the large-scale composite energy storage system is controlled to perform online capacity balancing, repair or capacity regeneration;

[0130] If the capacity self-test result is normal, perform a temperature condition self-test.

[0131] For example, the capacity self-test result can be determined based on the capacity balance self-test and the capacity health, and is used to characterize whether there is an abnormality in the system capacity. If the capacity self-test result is abnormal, it can be determined that the system capacity is abnormal, and the abnormal problem can be solved by online capacity balancing, repair or capacity regeneration. For example, the capacity self-test result can be represented by a numerical value. If the numerical value is greater than the first capacity threshold, it can be determined that the capacity abnormality is more serious, and the problem can be solved by online capacity regeneration. At this time, the capacity regeneration coupling platform can be controlled to start; if the numerical value is less than the first capacity threshold and greater than the second capacity threshold, it can be determined that the capacity abnormality is relatively minor, and the problem can be solved by online capacity balancing and repair. At this time, the online capacity repair unit and the online capacity balancing unit can be controlled to start; if the numerical value is less than the second capacity threshold, it can be determined that there is no abnormality in the system capacity, and at this time, the temperature condition self-test can be performed. In this way, the online capacity balancing capability of the entire composite energy storage system can be optimized, the online capacity repair level can be improved, and finally the long-term online capacity regeneration of the composite energy storage system can be achieved, greatly improving the long-life safety and manual maintenance-free level of the composite energy storage system.

[0132] In an optional embodiment, the controller may also be used to:

[0133] If the temperature condition self-test result is abnormal, the thermal energy coupling platform is controlled to start;

[0134] If the temperature condition self-test results are normal, the scheduling requirements are determined.

[0135] For example, if the temperature of a large-scale composite energy storage system exceeds a preset temperature range, it can be determined that the temperature condition self-test result is abnormal. At this time, the thermal energy coupling platform can be controlled to start. In this way, the thermal management distribution characteristics of short-term energy storage in a high-rate mode can be combined with the thermal management distribution characteristics of long-term energy storage in a low-rate mode. The distributed flow characteristics of short-term energy storage liquid cooling and long-term energy storage electrolyte can be brought into play. Heat storage technology can be appropriately introduced to combine the thermal management requirements under different modes such as refrigeration and heat dissipation and heating startup, thereby improving the comprehensive thermal management efficiency of the composite energy storage system.

[0136] If the temperature condition self-test results are normal, it can be determined that the large-scale composite energy storage system has passed the self-test. At this time, the power and energy dispatching requirements of the AC power grid can be generated according to the power grid monitoring status. The power and energy dispatching requirements may include long-term energy requirements and / or short-term energy requirements. The determination of the power and energy dispatching requirements of the AC power grid can be achieved based on the technical solutions in the relevant technologies, and there is no limitation here.

[0137] In an optional embodiment, the controller may be used to sequentially start corresponding platforms in the large-scale composite energy storage system according to scheduling requirements in the following manner:

[0138] If there is a long-term energy demand in the dispatching demand, the long-term energy storage power unit of the electric energy coupling platform, the electrolyte flow drive unit of the chemical energy coupling platform, the long-term energy platform, and the grid-connected coupling platform are controlled to start in sequence;

[0139] If there is a short-term energy demand in the dispatching demand, the short-term energy storage unit and the grid-connected coupling platform of the control power coupling platform are started in sequence.

[0140] In this way, the rapid frequency regulation capability of short-term energy storage in high-rate mode and the long-term peak regulation capability of long-term energy storage in low-rate mode can be combined, giving full play to the complementary characteristics of short-term energy storage compensating for the uncertainty of new energy fluctuation power and long-term energy storage balancing the seasonal energy uncertainty of new energy.

[0141] In an optional embodiment, the grid monitoring status is determined based on the grid impedance.

[0142] For example, if the grid impedance is within a first preset impedance range, the grid monitoring state can be determined to be a strong grid monitoring state, and if the grid impedance is within a second preset impedance range, the grid monitoring state can be determined to be a weak grid monitoring state. When the grid monitoring state is determined to be a weak grid monitoring state, it can be further determined whether the grid monitoring state is an off-grid state.

[0143] In an optional embodiment, the target operation mode includes a grid-following structure and parameters in a grid-connected mode, a grid-building structure and parameters in a grid-connected mode, or a grid-building structure and parameters in an off-grid mode.

[0144] For example, the relationship between the grid state and the target operation mode can be preset. For example, if the grid is in a strong grid state, the grid-following structure and parameters in the grid-connected mode can be activated; if the grid is in a weak grid state, the grid-building structure and parameters in the grid-connected mode can be activated; if the grid is in an off-grid state, the grid-building structure and parameters in the off-grid mode can be activated. In this way, the corresponding operation mode can be activated based on the actual state of the grid, thereby improving the operation efficiency, stability, economy and safety of the system.

[0145] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0146] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0147] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A large-scale composite energy storage system, characterized in that: The system comprises: A grid-connected coupling platform, connected to the AC grid via a grid interface unit, for providing an energy interface for the large-scale composite energy storage system to achieve energy management control and grid status monitoring functions; An electric energy coupling platform, used to control the short-term energy storage unit, the long-term energy storage power unit, and the long-term energy storage energy unit in the electric energy coupling platform according to the power and energy scheduling requirements, so as to realize the power coupling conversion and energy flow control of the large-scale composite energy storage system, wherein the scheduling requirements are determined based on the monitoring status of the power grid; A thermal energy coupling platform, used to control the temperature change and thermal energy distribution of the large-scale composite energy storage system according to the thermal management distribution characteristics of short-term energy storage and the thermal management distribution characteristics of long-term energy storage; A chemical energy coupling platform, which is used to optimize the long-term energy platform according to the control requirements of the long-term energy storage power unit in the electrical energy coupling platform to achieve balance, recovery and regeneration control of the electrolyte; The capacity regeneration coupling platform is used to achieve capacity regeneration by coupling the grid-connected coupling platform according to the capacity regeneration requirement of the chemical energy coupling platform.

2. The large-scale composite energy storage system according to claim 1, characterized in that: The grid-connected coupling platform comprises a three-phase first subsystem, each phase of the first subsystem comprises N series-connected cascaded DC-AC converters, and the three-phase common ground side is connected to the capacity regeneration coupling platform; The cascaded DC-AC converter is used to convert the energy provided by the AC power grid into DC power and input the DC power into the power coupling platform, or to convert the DC power of the power coupling platform into AC power and input the energy into the AC power grid; The grid-connected coupling platform is also used to convert the energy provided by the AC power grid into AC power of a target voltage, and input the AC power of the target voltage into the capacity regeneration coupling platform.

3. The large-scale composite energy storage system according to claim 1, characterized in that: The power coupling platform includes a three-phase second subsystem, each phase of the second subsystem includes M power coupling modules, each of the power coupling modules includes a short-time energy storage unit, a long-time energy storage power unit, a bidirectional DC-DC isolation unit, a short-time heat dissipation unit, a chemical energy power supply unit, a DC power interface terminal, a short-time thermal energy interface terminal, a long-time thermal energy interface terminal and a long-time chemical energy interface terminal; The DC power interface is connected to the short-time energy storage unit and the grid-connected coupling platform, and is connected to the long-time energy storage power unit through the bidirectional DC-DC isolation unit; The short-time thermal energy interface end is connected to the short-time energy storage unit through the short-time heat dissipation unit, and is connected to a first target device for thermal management, wherein the first target device for thermal management includes at least one of an independent heat dissipation unit and a short-time unit thermal energy interface end of another electric energy coupling module; The long-term thermal energy interface terminal is connected to the long-term energy storage power unit and the thermal management second target device, wherein the thermal management second target device includes at least one of the long-term unit thermal energy interface terminals of the independent heat dissipation unit and other power coupling modules; The chemical energy power supply unit connects the short-term energy storage unit to the chemical energy coupling platform via the long-term chemical energy interface.

4. The large-scale composite energy storage system according to claim 3, characterized in that: The first thermal management target device and the second thermal management target device are determined according to the optimization target of the heat dissipation system corresponding to the large-scale composite energy storage system. The optimization target is used to achieve coupling between short-time thermal management units, between long-time thermal management units, or between the short-time thermal management unit and the long-time thermal management unit with the minimum heat energy loss of the system as the target.

5. The large-scale composite energy storage system according to claim 3, characterized in that: The long-term energy storage power unit is used to realize the bidirectional conversion of chemical energy and electrical energy in the long-term energy storage pipeline according to the long-term energy storage energy management target, wherein the energy conversion mode of the long-term energy storage chemical energy and electrical energy is determined based on the long-term energy storage pipeline system corresponding to the large-scale composite energy storage system, and the energy conversion optimization process of the long-term energy storage chemical energy and electrical energy includes the long-term energy storage power unit self-drive optimization and the long-term energy storage power unit coupling drive optimization with other electrical energy coupling modules.

6. The large-scale composite energy storage system according to claim 1, characterized in that: The thermal energy coupling platform includes a three-phase third subsystem, each phase of the third subsystem includes O thermal energy coupling modules, and each of the thermal energy coupling modules includes a short-term thermal energy management unit, a long-term thermal energy management unit and a thermal coupling heat dissipation unit; The short-term thermal energy management unit is connected to the short-term thermal energy interface terminal of the power coupling platform; The long-term thermal energy management unit is connected to the long-term thermal energy interface terminal of the power coupling platform; The thermal coupling heat dissipation unit is connected to the short-term thermal energy management unit and the long-term thermal energy management unit, and the thermal coupling heat dissipation unit includes a heat storage unit.

7. The large-scale composite energy storage system according to claim 1, characterized in that: The chemical energy coupling platform includes a three-phase fourth subsystem, each phase of the fourth subsystem includes P chemical energy coupling modules, each of the chemical energy coupling modules includes an electrolyte flow driving unit, an online capacity balancing unit, an online capacity repair unit and an online capacity regeneration management unit; The electrolyte flow driving unit is connected to the chemical energy power supply unit and the long-term energy storage power unit of the power coupling platform, and is used to drive the electrolyte to circulate in a plurality of the long-term energy storage power units according to the charging and discharging requirements of the long-term energy storage power units, wherein the electrolyte flow driving unit and the long-term energy storage power units are connected via an electrolyte pipeline; The online capacity balancing unit is connected to the electrolyte flow driving unit and is connected to a plurality of long-term energy storage units of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to drive the capacity balance distribution of the electrolyte in the plurality of long-term energy storage units according to the capacity balance requirements of the long-term energy platform; The online capacity repair unit is connected to the electrolyte flow driving unit and is connected to a plurality of long-term energy storage units of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to drive the capacity repair distribution of the electrolyte in the plurality of long-term energy storage units according to the capacity repair requirements of the long-term energy platform; The online capacity regeneration management unit is connected to the electrolyte flow driving unit and the capacity regeneration coupling platform, and is connected to multiple long-term energy storage units of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to drive the capacity regeneration distribution of the electrolyte in the multiple long-term energy storage units according to the capacity regeneration requirements of the long-term energy platform.

8. The large-scale composite energy storage system according to claim 7, characterized in that: The chemical energy coupling platform also includes a short-time energy storage safety management module, which is connected to the short-time energy storage unit of the electrical energy coupling platform and is used to control the capacity of the short-time energy storage unit according to safety operation requirements.

9. The large-scale composite energy storage system according to claim 1, characterized in that: The long-term energy platform includes a three-phase fifth subsystem, each phase of the fifth subsystem includes Q long-term energy storage energy units, and the long-term energy storage energy unit includes a positive electrode tank and a negative electrode tank; The long-term energy storage energy unit is connected to the long-term energy storage power unit of the electrical energy coupling platform through the chemical energy coupling platform to achieve online capacity balancing and online capacity repair; The long-term energy storage unit is also connected to the capacity regeneration coupling platform via the chemical energy coupling platform to achieve online capacity regeneration.

10. The large-scale composite energy storage system according to claim 9, characterized in that: The long-term energy platform is also used to couple the thermal coupling heat dissipation unit, the short-term thermal energy management unit or the long-term thermal energy management unit in the thermal energy coupling platform according to the temperature control and thermal energy distribution requirements, so as to optimize the regulation and energy distribution.

11. The large-scale composite energy storage system according to claim 1, characterized in that: The capacity regeneration coupling platform includes R three-phase parallel AC-DC converters and a long-time energy storage capacity regeneration unit corresponding to each of the AC-DC converters, wherein the AC-DC converter is connected to the three-phase common ground side of the grid-connected coupling platform; the long-time energy storage capacity regeneration unit includes a regenerative anode tank, a regenerative cathode tank and a regenerative power management unit for realizing electrolysis; The long-term energy storage capacity regeneration unit is connected to the online capacity regeneration management unit of the chemical energy coupling platform, and is connected to the positive electrode tank and the negative electrode tank of the long-term energy platform through the distribution of the electrolyte pipeline, and is used to introduce the electrolyte that needs to be regenerated in the long-term energy storage unit into the regeneration anode tank or the regeneration cathode tank of the long-term energy storage capacity regeneration unit when in the regeneration mode; and after adding the regeneration material, electrolysis is carried out through the AC-DC converter to complete the regeneration process of the electrolyte. After the regeneration is completed, the electrolyte is controlled by the online capacity regeneration management unit to flow from the regeneration anode tank and the regeneration cathode tank to the positive electrode tank and the negative electrode tank respectively, so as to realize the system capacity regeneration distribution.

12. The large-scale composite energy storage system according to claim 11, characterized in that: The long-term energy storage capacity regeneration unit is also used to control the AC end of the AC-DC converter to maintain a zero voltage point, the DC end to maintain an operating reference voltage in the electrolytic cell, and the regeneration anode tank and the regeneration cathode tank to maintain an active standby state when not in regeneration mode.

13. The large-scale composite energy storage system according to claim 1, characterized in that: The large-scale composite energy storage system further includes a controller, which is used to: Controlling the large-scale composite energy storage system to perform self-test, wherein the self-test includes periodic fault self-test, non-periodic fault self-test, capacity self-test and temperature condition self-test, and the non-periodic fault self-test is performed when a target parameter in the large-scale composite energy storage system reaches a corresponding reference threshold; If the self-check passes, determining the power and energy dispatching requirements of the AC power grid; According to the scheduling requirements, starting the corresponding platforms in the large-scale composite energy storage system in sequence; After the grid-connected coupling platform is started, the target operation mode is started according to the monitoring status of the power grid.

14. The large-scale composite energy storage system according to claim 13, characterized in that: The controller is also used for: If the periodic fault self-test result or the non-periodic fault self-test result is abnormal, the fault point is isolated or removed.

15. The large-scale composite energy storage system according to claim 13, characterized in that: The controller is also used for: If there is no abnormality in the periodic fault self-test result and the non-periodic fault self-test result, the capacity self-test is performed.

16. The large-scale composite energy storage system according to claim 15, characterized in that: The controller is also used for: If the capacity self-test result is abnormal, the large-scale composite energy storage system is controlled to perform online capacity balancing, repair or capacity regeneration; If the capacity self-test result is normal, the temperature condition self-test is performed.

17. The large-scale composite energy storage system according to claim 16, characterized in that: The controller is also used for: If the temperature condition self-test result is abnormal, controlling the thermal energy coupling platform to start; If the temperature condition self-check result is normal, the scheduling requirement is determined.

18. The large-scale composite energy storage system according to claim 13, characterized in that: The controller is used to start the corresponding platforms in the large-scale composite energy storage system in sequence according to the scheduling requirements in the following manner: If the dispatching demand has a long-term energy demand, the long-term energy storage power unit of the electric energy coupling platform, the electrolyte flow drive unit of the chemical energy coupling platform, the long-term energy platform, and the grid-connected coupling platform are controlled to start in sequence; If the dispatching demand has a short-term energy demand, the short-term energy storage unit of the electric energy coupling platform and the grid-connected coupling platform are controlled to start in sequence.

19. The large-scale composite energy storage system according to claim 13, characterized in that: The grid monitoring status is determined based on grid impedance.

20. The large-scale composite energy storage system according to claim 13, characterized in that: The target operation mode includes a grid-following structure and parameters in a grid-connected mode, a grid-building structure and parameters in a grid-connected mode, or a grid-building structure and parameters in an off-grid mode.

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