Vanadium redox flow battery energy storage system based on super capacitor and black start method thereof

Abstract

This invention discloses a vanadium redox flow battery energy storage system based on a supercapacitor, comprising a station substation transformer, a supercapacitor, a station load for energy storage, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system includes battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station substation transformer is connected to the high-voltage bus via circuit breaker 1 and to the low-voltage bus of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station substation transformer is connected to circuit breakers 3 and 4. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the station load for energy storage. Circuit breakers 5, 6, 7, and 9 are connected in parallel on the low-voltage bus away from circuit breaker 4. Circuit breakers 5 and 9 are connected to the energy storage converter.

Description

Technical Field

[0001] This invention belongs to the field of energy storage technology, specifically relating to a vanadium redox flow battery energy storage system based on supercapacitors, and also to a black-start method for the vanadium redox flow battery energy storage system based on supercapacitors. Background Technology

[0002] my country's modern power system is extremely complex, connecting a large number of generators, transformers and transmission and distribution lines. In the event of a large-scale power outage, without black start measures, the power grid will recover very slowly, causing great losses to the national economy and people's lives, and may even affect social stability.

[0003] Traditional black-start power sources typically employ hydroelectric generators and gas turbines, but these methods have limitations. Hydroelectric generators are constrained by the distribution of hydropower resources, while gas turbines suffer from high maintenance costs. Therefore, energy storage systems have gained attention as a novel black-start power source. Energy storage systems offer advantages such as wide distribution, flexible site selection, lack of resource constraints, and rapid mode switching. They can effectively improve the grid's peak-shaving and frequency regulation capabilities and quickly activate energy storage devices to restore power supply in the event of grid failures. Summary of the Invention

[0004] The first objective of this invention is to provide a supercapacitor-based vanadium redox flow battery energy storage system to improve the grid's peak shaving and frequency regulation capabilities, and to quickly start the energy storage device and restore grid power supply in the event of a grid failure.

[0005] To achieve the above objectives, the technical solution adopted by this invention is: a vanadium redox flow battery energy storage system based on a supercapacitor, comprising a station substation transformer, a supercapacitor, an energy storage station load, and multiple vanadium redox flow battery energy storage systems; each vanadium redox flow battery energy storage system includes battery units, a DC side of an energy storage converter connected to the battery units, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter; the high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station; the station substation transformer is connected to the high-voltage bus via circuit breaker 1. The station service transformer is connected to the low-voltage busbar of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breaker 3 and circuit breaker 4 respectively. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the energy storage power station load. Circuit breaker 5, circuit breaker 6, circuit breaker 7 and circuit breaker 9 are connected in parallel in sequence away from circuit breaker 4. Circuit breaker 5 and circuit breaker 9 are connected to the energy storage converter. The low-voltage busbar between circuit breaker 6 and circuit breaker 7 and between circuit breaker 7 and circuit breaker 9 is disconnected.

[0006] As a preferred technical solution of the present invention, the supercapacitor is composed of a supercapacitor cluster, a supercapacitor converter, and a high-voltage box connected by wires.

[0007] As a preferred technical solution of the present invention, the energy storage converter controls the working state of the entire vanadium redox flow battery energy storage system through the inverter inside it.

[0008] As a preferred embodiment of the present invention, the energy storage converter is equipped with a sensor.

[0009] As a preferred embodiment of the present invention, the sensor is used to detect the voltage and frequency of the microgrid bus.

[0010] As a preferred technical solution of the present invention, the load of the energy storage station includes a circulating pump, a chiller, a battery management system, and an energy management system for the operation of the energy storage system.

[0011] As a preferred technical solution of the present invention, the components are connected by cables.

[0012] The second objective of this invention is to provide a black-start method for a supercapacitor-based vanadium redox flow battery energy storage system, which can improve the grid's peak-shaving and frequency regulation capabilities and quickly start the energy storage device to restore grid power supply in the event of a grid fault.

[0013] To achieve the above objectives, the technical solution adopted by this invention is: a black-start method for a supercapacitor-based vanadium redox flow battery energy storage system, comprising: After starting work, determine whether the microgrid is running. When running, monitor whether the bus voltage of the microgrid is less than the rated voltage range. If it is not running, it means that the microgrid has stopped running. When the microgrid bus voltage is below the rated voltage range, shut down all inverters, disconnect all circuit breakers, and clear all fault information; if the bus voltage is within the rated voltage range, continue to monitor grid data. The system detects whether the voltage and frequency of the microgrid bus reach the rated voltage range using sensors. If the grid voltage and frequency meet the grid connection requirements, the system operates in grid-connected mode; otherwise, it operates in off-grid mode. In grid-connected mode, the circuit breaker at the grid connection point is closed, and the inverters are started in the grid-connected mode startup sequence. The system constantly monitors whether the inverters generate fault alarms. If there are no alarms, the loads are connected to the system in sequence. If an alarm is generated, a shutdown command is sent to the inverter that generated the fault alarm, and a fault alarm is issued to the system. In off-grid mode, the SOC of each energy storage device is compared, and a black start sequence is generated from high to low. Devices with SOC < 40% are not added to the sequence, and faulty devices are not added to the sequence. There are i energy storage converters participating in the black start. When i>1, start the a-th energy storage converter. After successful startup, start the second energy storage converter, and so on until a=i. If startup fails, shut down the energy storage converter, upload the generated fault information, and remove the device from the next black start sequence. Recalculate the number of energy storage converters participating in the black start. When a=i, it proves that all energy storage converters in the sequence are started. When the grid voltage and frequency are constantly monitored and are within the normal range, the system can start the secondary frequency regulation and secondary voltage regulation algorithm, connect the renewable energy unit at one time, calculate the maximum output power of the currently connected energy storage, and connect the loads in sequence according to the importance and size of the load.

[0014] The beneficial effects of this invention are as follows: The vanadium redox flow battery energy storage system based on supercapacitors fully utilizes existing grid capacity. It uses supercapacitors to provide a black-start method for the vanadium redox flow battery system. The supercapacitor UPS, with its advantages of high safety, high cycle life, and environmental friendliness, is perfectly integrated with the vanadium redox flow battery. Utilizing advanced control strategies, it completes the black-start function of the vanadium redox flow battery energy storage. Since the black-start of vanadium redox flow battery systems on the market is mainly provided by lead-acid batteries as auxiliary power, there are no existing black-start cases combining supercapacitors. This invention not only solves the complex configuration problems of ordinary UPS systems that primarily use lead-acid batteries in terms of fire protection, safety, and environmental protection, but also sets a precedent in the field of hybrid energy storage. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of a vanadium redox flow battery energy storage system based on a supercapacitor according to the present invention. Figure 2 This is a schematic diagram of a black-start method for a supercapacitor-based vanadium redox flow battery energy storage system according to the present invention. Detailed Implementation

[0016] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0018] Example 1 like Figure 1 As shown, the present invention discloses a vanadium redox flow battery energy storage system based on a supercapacitor, comprising a station substation transformer, a supercapacitor, a station load for energy storage, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system includes battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station substation transformer is connected to the high-voltage bus via circuit breaker 1. The transformer is connected to the low-voltage busbar of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breaker 3 and circuit breaker 4 respectively. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the energy storage station load. Circuit breaker 5, circuit breaker 6, circuit breaker 7 and circuit breaker 9 are connected in parallel in sequence away from circuit breaker 4. Circuit breaker 5 and circuit breaker 9 are connected to the energy storage converter. The low-voltage busbar between circuit breaker 6 and circuit breaker 7, and between circuit breaker 7 and circuit breaker 9 is disconnected.

[0019] The existing vanadium redox flow battery energy storage black start system mainly consists of six parts: station service transformer, supercapacitor UPS, station service load, energy storage step-up transformer, energy storage converter, and battery cells; these components are connected by cables. The station service transformer provides the main power source for the UPS and energy storage station service load. The energy storage station service load contains the circulating pump, chiller, battery management system, and energy management system for the operation of the energy storage system. The battery cells are energy storage units that store energy in electrolyte. The energy storage converter and step-up transformer are grid-connected devices that convert the energy from the battery into a voltage suitable for the power grid, thus achieving grid connection.

[0020] The present invention discloses a vanadium redox flow battery energy storage system based on supercapacitors. Its working principle is as follows: When the power system experiences a power outage, the energy storage converter (PCS) determines whether the black start conditions are met: confirming that the system is in a completely dark state, confirming that circuit breakers 1, 2, 5, and 9 have been tripped, confirming that the current available power of the energy storage station meets the black start power requirements, confirming that there are no abnormal alarms in the energy storage station, and confirming that the status of each module is normal.

[0021] After confirming that the above black start conditions are met, check that the standby status of the supercapacitor UPS is normal, and check that the control system, communication system, and fire protection system of the supercapacitor UPS are normal. Close circuit breaker 3 of the supercapacitor UPS used as the black start power supply, start the supercapacitor UPS power supply, and the supercapacitor UPS provides power to the load of the energy storage station. After reaching the rated voltage, close circuit breaker 4, and then restore all station power to the energy storage system, including the circulation system, refrigeration system, and ventilation system.

[0022] Once the energy storage system is capable of supplying power to the substation, circuit breakers 5, 6, 7, and 9 are closed, and circuit breaker 3 is opened, completing the black start.

[0023] This invention relates to a vanadium redox flow battery energy storage system based on supercapacitors. It fully utilizes existing grid capacity and employs supercapacitors to provide a black-start method for the vanadium redox flow battery system. The supercapacitor UPS, with its advantages of high safety, high cycle life, and environmental friendliness, is perfectly integrated with the vanadium redox flow battery. Utilizing advanced control strategies, it completes the black-start function of the vanadium redox flow battery energy storage. Since black-start of vanadium redox flow battery systems on the market is mainly provided by lead-acid batteries as auxiliary power, there are no existing black-start cases combining supercapacitors. This invention not only solves the complex configuration problems of ordinary UPS systems that primarily use lead-acid batteries in terms of fire protection, safety, and environmental protection, but also sets a precedent in the field of hybrid energy storage.

[0024] Example 2 like Figure 1 As shown in Example 1, in Example 2, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, including a station substation, a supercapacitor, a station load, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system includes battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station substation is connected to the high-voltage bus of the power station via circuit breaker 1. The station service transformer is connected to the low-voltage busbar of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breaker 3 and circuit breaker 4 respectively. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the energy storage power station load. Circuit breaker 5, circuit breaker 6, circuit breaker 7 and circuit breaker 9 are connected in parallel in sequence away from circuit breaker 4. Circuit breaker 5 and circuit breaker 9 are connected to the energy storage converter. The low-voltage busbar between circuit breaker 6 and circuit breaker 7, and between circuit breaker 7 and circuit breaker 9 is disconnected.

[0025] Unlike Example 1, in Example 2, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, wherein the supercapacitor is composed of a supercapacitor cluster, a supercapacitor converter, and a high-voltage box connected by wires.

[0026] Example 3 like Figure 1As shown in Example 1, in Example 2, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, including a station substation, a supercapacitor, a station load, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system includes battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station substation is connected to the high-voltage bus of the power station via circuit breaker 1. The station service transformer is connected to the low-voltage busbar of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breakers 3 and 4. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the energy storage station's load. Circuit breakers 5, 6, 7, and 9 are connected in parallel along the low-voltage busbar away from circuit breaker 4. Circuit breakers 5 and 9 are connected to the energy storage converter. The low-voltage busbars between circuit breakers 6 and 7, and between circuit breakers 7 and 9, are disconnected. The supercapacitor consists of a supercapacitor cluster, a supercapacitor converter, and a high-voltage box connected by conductors.

[0027] Unlike Example 2, in Example 3, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, in which the energy storage converter controls the operating state of the entire vanadium redox flow battery energy storage system through an inverter within it.

[0028] Example 4 like Figure 1 As shown in Example 3, in Example 4, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, including a station substation, a supercapacitor, a station load, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system includes battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station substation is connected to the high-voltage bus of the power station via circuit breaker 1. The station service transformer is connected to the low-voltage busbar of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breakers 3 and 4. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the energy storage station's load. Circuit breakers 5, 6, 7, and 9 are connected in parallel along the low-voltage busbar away from circuit breaker 4. Circuit breakers 5 and 9 are connected to the energy storage converter. The low-voltage busbars between circuit breakers 6 and 7, and between circuit breakers 7 and 9, are disconnected. The supercapacitor consists of a supercapacitor cluster, a supercapacitor converter, and a high-voltage box connected by conductors. The energy storage converter controls the operating state of the entire vanadium redox flow battery energy storage system through its internal inverter.

[0029] Unlike Example 3, in Example 4, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, in which a sensor is installed in the energy storage converter to detect the voltage and frequency of the microgrid bus.

[0030] Example 5 like Figure 1 As shown in Example 4, in Example 5, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, including a station substation, a supercapacitor, an energy storage station load, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system includes battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station substation is connected to the high-voltage bus of the power station via circuit breaker 1. The station service transformer is connected to the low-voltage busbar of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breakers 3 and 4. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the energy storage station's load. Circuit breakers 5, 6, 7, and 9 are connected in parallel along the low-voltage busbar away from circuit breaker 4. Circuit breakers 5 and 9 are connected to the energy storage converter. The low-voltage busbars between circuit breakers 6 and 7, and between circuit breakers 7 and 9, are disconnected. The supercapacitor consists of a supercapacitor cluster, a supercapacitor converter, and a high-voltage box connected by conductors. The energy storage converter controls the operating status of the entire vanadium redox flow battery energy storage system through its internal inverter. Sensors are installed inside the energy storage converter to detect the voltage and frequency of the microgrid busbar.

[0031] Unlike Example 4, in Example 5, the present invention provides a vanadium redox flow battery energy storage system based on a supercapacitor, wherein the load of the energy storage station includes a circulating pump, a chiller, a battery management system, and an energy management system for the operation of the energy storage system.

[0032] Example 6 like Figure 2 As shown, the present invention provides a black-start method for a supercapacitor-based vanadium redox flow battery energy storage system, comprising: After starting work, determine whether the microgrid is running. When running, monitor whether the bus voltage of the microgrid is less than the rated voltage range. If it is not running, it means that the microgrid has stopped running. When the microgrid bus voltage is below the rated voltage range, shut down all inverters, disconnect all circuit breakers, and clear all fault information; if the bus voltage is within the rated voltage range, continue to monitor grid data. The system detects whether the voltage and frequency of the microgrid bus reach the rated voltage range using sensors. If the grid voltage and frequency meet the grid connection requirements, the system operates in grid-connected mode; otherwise, it operates in off-grid mode. In grid-connected mode, the circuit breaker at the grid connection point is closed, and the inverters are started in the grid-connected mode startup sequence. The system constantly monitors whether the inverters generate fault alarms. If there are no alarms, the loads are connected to the system in sequence. If an alarm is generated, a shutdown command is sent to the inverter that generated the fault alarm, and a fault alarm is issued to the system. In off-grid mode, the SOC of each energy storage unit (i.e., the battery cells in the vanadium redox flow battery energy storage system) is compared, and a black start sequence is generated from high to low. Devices with SOC < 40% are not added to the sequence, and faulty devices are not added to the sequence. There are i energy storage converters participating in the black start. When i>1, start the a-th energy storage converter. After successful startup, start the second energy storage converter, and so on until a=i. If startup fails, shut down the energy storage converter, upload the generated fault information, and remove the device from the next black start sequence. Recalculate the number of energy storage converters participating in the black start. When a=i, it proves that all energy storage converters in the sequence are started. When the grid voltage and frequency are constantly monitored and are within the normal range, the system can start the secondary frequency regulation and secondary voltage regulation algorithm, connect the renewable energy unit at one time, calculate the maximum output power of the currently connected energy storage, and connect the loads in sequence according to the importance and size of the load.

[0033] This invention presents a black-start method for a vanadium redox flow battery energy storage system based on supercapacitors. It fully utilizes existing grid capacity and leverages supercapacitors to provide a black-start solution for the vanadium redox flow battery system. The supercapacitor UPS, with its advantages of high safety, high cycle life, and environmental friendliness, is perfectly integrated with the vanadium redox flow battery. Utilizing advanced control strategies, it completes the black-start function of the vanadium redox flow battery energy storage. Since the black-start of vanadium redox flow battery systems on the market is mainly provided by lead-acid batteries as auxiliary power, there are no existing black-start cases combining supercapacitors. This invention not only solves the complex configuration problems of ordinary UPS systems that primarily use lead-acid batteries in terms of fire protection, safety, and environmental protection, but also sets a precedent in the field of hybrid energy storage.

[0034] The foregoing description illustrates and describes several preferred embodiments of the invention. However, as previously stated, it should be understood that the invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the invention should be within the protection scope of the appended claims.

Claims

1. A vanadium redox flow battery energy storage system based on supercapacitors, characterized in that, The system includes a station service transformer, a supercapacitor, a station service load, and multiple vanadium redox flow battery energy storage systems. Each vanadium redox flow battery energy storage system comprises battery cells, a DC side of an energy storage converter connected to the battery cells, and a low-voltage side of an energy storage step-up transformer connected to the AC side of the energy storage converter. The high-voltage side of the energy storage step-up transformer is connected to the high-voltage bus of the energy storage power station. The station service transformer is connected to the high-voltage bus via circuit breaker 1, and to the low-voltage bus of the energy storage power station via circuit breaker 2. Circuit breaker 2 of the station service transformer is connected to circuit breakers 3 and 4. Circuit breaker 3 is connected to the supercapacitor, and circuit breaker 4 is connected to the station service load. Circuit breakers 5, 6, 7, and 9 are connected in parallel on the low-voltage bus away from circuit breaker 4. Circuit breakers 5 and 9 are connected to the energy storage converter. The low-voltage bus between circuit breakers 6 and 7, and between circuit breakers 7 and 9, is disconnected.

2. The all-vanadium redox flow battery energy storage system based on supercapacitors according to claim 1, characterized in that, The supercapacitor is composed of a supercapacitor cluster, a supercapacitor converter, and a high-voltage box connected by wires.

3. The all-vanadium redox flow battery energy storage system based on supercapacitors according to claim 2, characterized in that, The energy storage converter controls the operating status of the entire vanadium redox flow battery energy storage system through its internal inverter.

4. The all-vanadium redox flow battery energy storage system based on supercapacitors according to claim 3, characterized in that, The energy storage converter is equipped with sensors.

5. The all-vanadium redox flow battery energy storage system based on supercapacitors according to claim 4, characterized in that, The sensor is used to detect the voltage and frequency of the microgrid bus.

6. The all-vanadium redox flow battery energy storage system based on supercapacitors according to claim 5, characterized in that, The load of the energy storage station includes the circulating pump, chiller, battery management system, and energy management system that operate the energy storage system.

7. The all-vanadium redox flow battery energy storage system based on supercapacitors according to claim 6, characterized in that, The components are connected by cables.

8. A black-start method for a vanadium redox flow battery energy storage system based on supercapacitors, characterized in that, include: After starting work, determine whether the microgrid is running. When running, monitor whether the bus voltage of the microgrid is less than the rated voltage range. If it is not running, it means that the microgrid has stopped running. When the microgrid bus voltage is below the rated voltage range, shut down all inverters, disconnect all circuit breakers, and clear all fault information; if the bus voltage is within the rated voltage range, continue to monitor grid data. The system detects whether the voltage and frequency of the microgrid bus reach the rated voltage range by sensors. If the grid voltage and frequency meet the grid connection requirements, the system will operate in grid connection mode. If the grid connection requirements are not met, the system will operate in off-grid mode. In grid-connected mode, the circuit breaker at the grid connection point is closed, and the inverters are started in the grid-connected mode startup sequence. The system constantly monitors whether the inverters generate fault alarms. If there are no alarms, the loads are connected to the system in sequence. If an alarm is generated, a shutdown command is sent to the inverter that generated the fault alarm, and a fault alarm is issued to the system. In off-grid mode, the SOC of each energy storage device is compared, and a black start sequence is generated from high to low. Devices with SOC < 40% are not added to the sequence, and faulty devices are not added to the sequence. There are i energy storage converters participating in the black start. When i>1, start the a-th energy storage converter. After successful startup, start the second energy storage converter, and so on until a=i. If startup fails, shut down the energy storage converter, upload the generated fault information, and remove the device from the next black start sequence. Recalculate the number of energy storage converters participating in the black start. When a=i, it proves that all energy storage converters in the sequence are started. When the grid voltage and frequency are constantly monitored and are within the normal range, the system can start the secondary frequency regulation and secondary voltage regulation algorithm, connect the renewable energy unit at one time, calculate the maximum output power of the currently connected energy storage, and connect the loads in sequence according to the importance and size of the load.

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