Safety control method and device for energy storage system based on residual current protection circuit breaker

Abstract

The application provides a residual current circuit breaker-based energy storage system safety control method and device, which comprises the following steps: if it is determined that the commercial power supply is disconnected, a control instruction is sent to a grid-connected circuit breaker, a first port of an energy management system is set to 1, a second port is set to 0, a tripping command is obtained, the grid-connected circuit breaker is controlled to execute a tripping operation based on the tripping command; a stop running instruction is sent to the energy storage converter based on the action signal of the tripping operation to control the energy storage converter to stop running; a mode switching instruction is sent to the energy storage converter based on the state information of the energy storage converter stopping running to switch the energy storage converter to an off-grid running mode, off-grid running mode state information is obtained; based on the state information of the communication interruption, the state information that the first port outputs 1 and the second port outputs 0 and the off-grid running mode state information, a start instruction is sent to the energy storage converter to control the energy storage converter to start running. The application guarantees the reliable operation of the energy storage system in an unstable power grid area.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and in particular to a safety control method and device for an energy storage system based on a residual current circuit breaker. Background Technology

[0002] In areas with inadequate power grid infrastructure and frequent or prolonged power outages, energy storage systems are often used as backup power. Their core function is to replenish the energy storage unit with mains power. When the mains power fails and cannot meet the load's operational needs, the energy storage device must promptly switch from grid-connected mode to off-grid mode to discharge, ensuring power continuity. Currently, traditional automatic grid-connected / off-grid switching primarily employs a combination of a static transfer switch (STS) and an automatic transfer switch (ATS). The STS detects grid voltage, phase, and other data, exchanging data with the energy storage converter. If no mains power data is detected, it immediately reports to the energy storage converter, enabling seamless grid-connected / off-grid mode switching of the energy storage converter within 20ms. The ATS then switches between mains power and the energy storage power source to complete the power supply circuit transition.

[0003] However, this traditional mode has a problem: when the backup power supply of the automatic transfer switch (ATS) is not connected and only the main power supply is connected, the internal transfer switch of the ATS will not automatically switch to the backup power supply side due to the ATS's own settings, but will remain on the main power supply side; when the energy storage cabinet is in an off-grid operation state, the stored energy will be fed back to the grid along the ATS, creating a serious safety hazard. Summary of the Invention

[0004] This invention provides a safety control method and device for an energy storage system based on a residual current circuit breaker, to ensure the reliable operation of the energy storage system in areas with unstable power grids.

[0005] In a first aspect, the present invention provides a safety control method for an energy storage system based on a residual current circuit breaker, comprising:

[0006] If a power outage is determined based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system, a control command is sent to the grid-connected circuit breaker to set the first digital output port of the energy management system to 1 and the second digital output port to 0, thereby obtaining a tripping command, and the grid-connected circuit breaker is controlled to perform a tripping operation based on the tripping command.

[0007] Based on the action signal of the grid-connected circuit breaker performing the tripping operation, a shutdown command is sent to the energy storage converter, and the energy storage converter is controlled to stop operation based on the shutdown command;

[0008] Based on the status information of the energy storage converter stopping operation, a mode switching command is sent to the energy storage converter to switch the operation mode of the energy storage converter from grid-connected operation mode to off-grid operation mode, thereby obtaining the off-grid operation mode status information of the energy storage converter.

[0009] Based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, a start command is sent to the energy storage converter to control the energy storage converter to start operation based on the start command.

[0010] The safety control method for an energy storage system based on a residual current circuit breaker provided by the present invention further includes:

[0011] If it is determined that the load is in an overload state based on the real-time value of the load current at the output terminal of the energy storage converter, a derating command is sent to the energy storage converter to obtain a derating operation parameter, and the energy storage converter is controlled to reduce the output power based on the derating operation parameter.

[0012] Based on the operating status information after reducing the output power, the load current value after the first derating at the output terminal of the energy storage converter is collected. If it is determined that the overload state has not been relieved based on the load current value after the first derating, a second derating command is sent to the energy storage converter to obtain the second derating operating parameters, and the energy storage converter is controlled to continue to reduce the output power based on the second derating operating parameters.

[0013] Based on the operating status information after further reducing the output power, the load current value after the second derating at the output terminal of the energy storage converter is collected. If it is determined from the result of the load current value after the second derating that the overload state has not been relieved, a status query command is sent to the grid-connected circuit breaker to obtain the second communication status information of the grid-connected circuit breaker.

[0014] The operation of the energy storage converter is controlled based on the second communication status information.

[0015] According to the energy storage system safety control method based on residual current protection circuit breaker provided by the present invention, the operation of the energy storage converter is controlled based on the second communication status information, including:

[0016] If it is determined based on the second communication status information that the mains power has not been restored, then a load shedding command is sent to the load distribution controller in the energy storage system to obtain the priority load shedding, and the load distribution controller is controlled to cut off the power supply circuit of non-critical loads based on the priority load shedding.

[0017] If the load overload condition is determined to be resolved based on the load current value at the output terminal of the energy storage converter after the load is disconnected, obtained from the power supply status information after the non-critical load is disconnected, a stable operation command is sent to the energy storage converter to obtain stable operation parameters, and the energy storage converter is controlled to maintain the current output power operation based on the stable operation parameters.

[0018] If it is determined that the overload condition has not been resolved, an emergency stop command is sent to the energy storage converter, and the energy storage converter is controlled to stop operating based on the emergency stop command. A trip hold command is sent to the grid-connected circuit breaker, and the grid-connected circuit breaker is controlled to maintain the trip state based on the trip hold command.

[0019] The safety control method for an energy storage system based on a residual current circuit breaker provided by the present invention further includes:

[0020] The load distribution status of each energy storage converter is determined based on the output power and current data of each energy storage converter, and the average output power of all energy storage converters is calculated based on the load distribution status of each energy storage converter to obtain the first average output power value.

[0021] If it is determined that the output power of each energy storage converter is unbalanced based on the first average output power value, then the energy storage converter with an output power higher than the first average output power value is selected to obtain the high-load energy storage converter, and a power reduction command is sent to the high-load energy storage converter.

[0022] If the adjusted output power value of the high-load energy storage converter, obtained from the operating status information collected after the first power reduction command, is not close to the first average output power value, a second power reduction command is sent to the high-load energy storage converter to obtain the second reduction parameters, and the high-load energy storage converter is controlled to continue to reduce the output power based on the second reduction parameters.

[0023] Based on the operating status information after further reducing the output power, energy storage converters with output power lower than the first average output power value are selected to obtain low-load energy storage converters, and the operation of the energy storage converters is controlled based on the low-load energy storage converters.

[0024] The energy storage system safety control method based on a residual current circuit breaker provided by the present invention, which controls the operation of the energy storage converter based on the low-load energy storage converter, includes:

[0025] A power increase command is sent to the low-load energy storage converter. If the adjusted output power value of the low-load energy storage converter, collected based on the operating status information after the first power increase command, is not close to the first average output power value, a second power increase command is sent based on the low-load energy storage converter to obtain the second increase parameters. Based on the second increase parameters, the low-load energy storage converter is controlled to continue to increase its output power.

[0026] The second average output power value is calculated based on the balanced adjustment output power values ​​of all energy storage converters collected from the operating status information after the continued increase in output power.

[0027] Determine whether the deviation between the output power of each energy storage converter and the second average output power value is within the allowable range; if it is within the allowable range, send an equalization maintenance command to all energy storage converters, and control all energy storage converters to maintain the current output power based on the equalization maintenance command.

[0028] The safety control method for an energy storage system based on a residual current circuit breaker provided by the present invention further includes:

[0029] The start-up preparation signal based on the current suppression circuit controls the current suppression module to enter the working state, and sends a soft-start command to the energy storage converter based on the status information of the current suppression module after entering the working state, thereby obtaining the soft-start voltage rise rate parameter.

[0030] Based on the soft-start voltage rise rate parameter, the energy storage converter is controlled to increase the output voltage at a set rate.

[0031] Based on the voltage data after the output voltage is increased, a pre-charge current acquisition command is sent to the current detection module to obtain the pre-charge current data at the output of the energy storage converter, and based on the pre-charge current data, it is determined whether the pre-charge current exceeds the inrush current threshold.

[0032] If the pre-charge current exceeds the inrush current threshold based on the judgment result, a current limiting adjustment command is sent to the current suppression module to obtain the current limiting resistor access parameters, and the current suppression module is controlled to connect a current limiting resistor with a larger resistance value based on the current limiting resistor access parameters.

[0033] Based on the status information after connecting a larger resistance current limiting resistor, a pre-charge current acquisition command is sent to the current detection module to obtain the adjusted pre-charge current data, and the operation of the energy storage converter is controlled based on the adjusted pre-charge current data.

[0034] According to the energy storage system safety control method based on residual current protection circuit breaker provided by the present invention, the operation of the energy storage converter is controlled based on the adjusted precharge current data, including:

[0035] If, based on the adjusted pre-charge current data, it is determined that the pre-charge current has dropped below the inrush current threshold, a closing preparation command is sent to the grid-connected circuit breaker to obtain the circuit status data before closing, and it is determined whether the grid-connected circuit has the conditions for closing based on the circuit status data.

[0036] If the closing conditions are met, a slow closing command is sent to the grid-connected circuit breaker to obtain the closing speed parameters, and the grid-connected circuit breaker is controlled to slowly perform the closing operation based on the closing speed parameters.

[0037] Based on the operating status information after slow closing, a grid-connected inrush current acquisition command is sent to the current detection module to obtain the inrush current data at the moment of closing. If it is determined based on the inrush current data at the moment of closing that the inrush current is within the allowable range, a current limiting release command is sent to the current suppression module, and the current limiting release command is used to control the current suppression module to gradually disconnect the current limiting resistor.

[0038] Based on the status information after gradually removing the current-limiting resistor, a power recovery command is sent to the energy storage converter to obtain the power recovery rate parameter. Based on the power recovery rate parameter, the energy storage converter is controlled to increase the output power at a set rate until it returns to normal grid-connected power operation.

[0039] The safety control method for an energy storage system based on a residual current circuit breaker provided by the present invention further includes:

[0040] If it is determined based on the first communication status information that the mains power has been restored, then the energy storage converter is controlled to stop operating, and a mode switching command is sent to the energy storage converter based on the status information of the energy storage converter stopping operation, so as to switch the operating mode of the energy storage converter from the off-grid operating mode to the grid-connected operating mode, and obtain the grid-connected operating mode status information of the energy storage converter.

[0041] Based on the grid-connected operation mode status information, a control command is sent to the grid-connected circuit breaker to set the first digital output port of the energy management system to 0 and the second digital output port to 1, thereby obtaining a closing command, and controlling the grid-connected circuit breaker to perform a closing operation based on the closing command.

[0042] Based on the normal communication status information of the grid-connected circuit breaker, the status information of the grid-connected circuit breaker being in closed operation, the status information of the first digital output port outputting 0 and the second digital output port outputting 1, and the grid-connected operation mode status information of the energy storage converter, a start command is sent to the energy storage converter, and the energy storage converter is controlled to start operation based on the start command.

[0043] In a second aspect, the present invention also provides a safety control device for an energy storage system based on a residual current circuit breaker, applied to the safety control method for an energy storage system based on a residual current circuit breaker as described in any of the first aspects, wherein the safety control device for an energy storage system based on a residual current circuit breaker includes:

[0044] The tripping control module is used to send a control command to the grid-connected circuit breaker if it is determined that a power outage has occurred based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system. The command sets the first digital output port of the energy management system to 1 and the second digital output port to 0 to obtain a tripping command, and controls the grid-connected circuit breaker to perform a tripping operation based on the tripping command.

[0045] The first energy storage control module is used to send a shutdown command to the energy storage converter based on the action signal of the grid-connected circuit breaker performing a tripping operation, and to control the energy storage converter to stop operating based on the shutdown command;

[0046] The mode switching module is used to send a mode switching command to the energy storage converter based on the status information of the energy storage converter stopping operation, so as to switch the operation mode of the energy storage converter from the grid-connected operation mode to the off-grid operation mode, and obtain the off-grid operation mode status information of the energy storage converter.

[0047] The second energy storage control module is used to send a start command to the energy storage converter based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, so as to control the energy storage converter to start and operate based on the start command.

[0048] The present invention also provides an electronic device, comprising: a memory for storing computer software programs; and a processor for reading and executing the computer software programs, thereby realizing the energy storage system safety control method based on residual current circuit breakers as described above.

[0049] The present invention also provides a non-transitory computer-readable storage medium storing a computer software program, which, when executed by a processor, implements the energy storage system safety control method based on a residual current circuit breaker as described above.

[0050] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the energy storage system safety control method based on a residual current circuit breaker as described above.

[0051] The safety control method and device for energy storage systems based on residual current circuit breakers provided in this invention monitors the communication status information of the grid-connected circuit breaker to obtain the judgment result of mains power outage or restoration, providing an accurate trigger basis for subsequent grid-connected to off-grid switching, avoiding switching delays caused by detection logic defects. Based on the judgment result of mains power outage, the grid-connected circuit breaker is controlled to trip, directly cutting off the connection between the mains power and the energy storage system, fundamentally eliminating the safety hazard of energy storage power being fed back into the grid. Based on the tripping action signal, the energy storage converter is controlled to shut down, ensuring that the equipment is in a stable state before mode switching and avoiding power disturbance. Based on the shutdown status information, the energy storage converter is switched to off-grid mode to prepare for off-grid power supply. Based on the communication interruption information, tripping control status, and off-grid mode status, the off-grid operation of the energy storage converter is started, ensuring the continuity of load power supply, thereby ensuring the reliable operation of the energy storage system in areas with unstable power grids. Attached Figure Description

[0052] Figure 1 This is a flowchart illustrating the safety control method for an energy storage system based on a residual current protection circuit breaker provided by the present invention.

[0053] Figure 2 This is a schematic diagram of the structure of the energy storage system safety control device based on the residual current protection circuit breaker provided by the present invention;

[0054] Figure 3 A schematic diagram of an embodiment of the electronic device provided in this invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] In the description of this invention, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use the invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be made without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0058] Optional, see below Figure 1 , Figure 1 This is a flowchart illustrating the safety control method for an energy storage system based on a residual current circuit breaker provided by the present invention. In this embodiment, the executing entity of the safety control method for an energy storage system based on a residual current circuit breaker is an energy storage control device. Therefore, the safety control method for an energy storage system based on a residual current circuit breaker includes:

[0059] Step 10: If it is determined that the mains power has been interrupted based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system, a control command is sent to the grid-connected circuit breaker to set the first digital output port of the energy management system to 1 and the second digital output port to 0, thereby obtaining a tripping command, and the grid-connected circuit breaker is controlled to perform a tripping operation based on the tripping command.

[0060] Optionally, the energy storage control device monitors the first communication status information of the grid-connected circuit breaker (NM2LC residual current protection circuit breaker) in real time through the energy management system (EMS). This information is transmitted via a 485 communication line, corresponding to the 485A (port 4) and 485B (port 5) auxiliary ports of the circuit breaker. When the first communication status information indicates a mains power outage, the energy storage control device sends a control command to the grid-connected circuit breaker through the energy management system: setting the first digital output port (DO1) of the energy management system to 1 and the second digital output port (DO2) to 0. Since the tripping operation corresponds to ports 2 and 3 in the control ports of the grid-connected circuit breaker, in this state, the output of 1 from DO1 and the output of 0 from DO2 will trigger the tripping logic of the control port, forming a tripping command, which in turn controls the grid-connected circuit breaker to perform a tripping operation and disconnect the connection with the mains power.

[0061] In one embodiment, the energy management system monitors the first communication status information of the grid-connected circuit breaker via 485 communication as "mains voltage 0V, lasting 5 seconds" (determined as mains power failure), triggering the control logic to cause the energy management system's DO1 to output 1 (high level) and DO2 to output 0 (low level). This signal is transmitted to the control port of the grid-connected circuit breaker. Ports 2 and 3 connect the tripping circuit due to the high-level signal of DO1, and the grid-connected circuit breaker performs the tripping operation, the mechanical contacts open, and electrical isolation from the mains power is completed.

[0062] Step 20: Send a shutdown command to the energy storage converter based on the action signal of the grid-connected circuit breaker performing the tripping operation, and control the energy storage converter to stop operation based on the shutdown command.

[0063] Furthermore, after the grid-connected circuit breaker performs the tripping operation, it feeds back the tripping action signal (such as mechanical position signal or communication status word change) to the energy management system through its auxiliary port or communication line.

[0064] Furthermore, after the energy storage control device receives the action signal, it sends a shutdown command to the energy storage converter (PCS) through the energy management system. After receiving the shutdown command, the energy storage converter gradually reduces the output power to 0, disconnects the internal power circuit, and stops operating.

[0065] Continuing with the above embodiment, after the grid-connected circuit breaker completes its tripping, it sends a "tripping status: tripped" action signal to the energy management system via 485 communication. Upon receiving this signal, the energy storage control device controls the energy management system to send a "stop" command to the energy storage converter (e.g., sending function code 0x06 via the Modbus protocol to set the control register to 0x0000). Upon receiving the command, the energy storage converter gradually reduces its output current from 50A to 0A, disconnects the IGBT drive signal, enters the stop state, and sends a "operating status: stopped" signal back to the energy management system.

[0066] Step 30: Based on the status information of the energy storage converter stopping operation, a mode switching command is sent to the energy storage converter to switch the operation mode of the energy storage converter from grid-connected operation mode to off-grid operation mode, and the off-grid operation mode status information of the energy storage converter is obtained.

[0067] Furthermore, after obtaining the status information of the energy storage converter being shut down (e.g., "Operating Status: Shutdown") from the energy management system, the energy storage control device sends a mode switching command to the energy storage converter, requesting it to switch from grid-connected operation mode to off-grid operation mode. The energy storage converter performs the mode switching while in a shutdown state, adjusting its internal control strategy (e.g., switching from grid-synchronous control to independent voltage / frequency control), and after completing the switch, it feeds back the off-grid operation mode status information (e.g., "Operating Mode: Off-grid") to the energy management system.

[0068] Continuing with the above embodiment, after the energy storage converter reports "Operating Status: Shutdown," the energy storage control device controls the energy management system to send a "Mode Switch: Off-Grid" command to the energy storage converter (e.g., by setting the mode register to 0x0002 via the Modbus protocol). Upon receiving the command, the energy storage converter loads the voltage loop (380V±5%) and frequency loop (50Hz±0.5Hz) control parameters for off-grid mode, completes the switch, and reports "Operating Mode: Off-Grid." At this point, the energy storage converter is in an off-grid shutdown state, awaiting a startup command.

[0069] Step 40: Based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, a start command is sent to the energy storage converter to control the energy storage converter to start operation based on the start command.

[0070] Furthermore, the energy storage control device simultaneously monitors three conditions: 1. The communication status information of the grid-connected circuit breaker is "communication interrupted" (because communication with the mains power side may be lost after the circuit breaker is opened); 2. The first digital output port (DO1) of the energy management system outputs 1 and the second digital output port (DO2) outputs 0 (maintaining the open state); 3. The energy storage converter has fed back "off-grid operation mode status information". When all three conditions are met, the energy storage control device sends a start command to the energy storage converter through the energy management system. The energy storage converter starts from the off-grid shutdown state and enters the off-grid operation mode to provide power to the load. Continuing with the above embodiment, the energy storage control device monitors: 1. The grid-connected circuit breaker's 485 communication timed out (determined as "communication interrupted"); 2. DO1 outputs 1 and DO2 outputs 0 (the open state has not changed); 3. The energy storage converter feeds back "operation mode: off-grid". After the conditions are met, the energy storage control device controls the energy management system to send a "start" command to the energy storage converter (e.g., setting the control register to 0x0001). After receiving the command, the energy storage converter starts the off-grid inverter function, outputs 380V / 50Hz AC power to the load, and feeds back "Operating status: Off-grid operation".

[0071] Step 50: If it is determined that the mains power has been restored based on the first communication status information, the energy storage converter is controlled to stop operating, and a mode switching command is sent to the energy storage converter based on the status information of the energy storage converter stopping operation, so as to switch the operating mode of the energy storage converter from the off-grid operation mode to the grid-connected operation mode, and obtain the grid-connected operation mode status information of the energy storage converter.

[0072] Furthermore, the energy storage control device monitors the first communication status information of the grid-connected circuit breaker through the energy management system. When the information indicates that the mains power supply has been restored (e.g., the mains voltage and frequency have returned to normal range), it sends a shutdown command to the energy storage converter, controlling it to stop off-grid operation (output power drops to 0, disconnecting the power circuit). After obtaining the "shutdown" status information of the energy storage converter, it sends a mode switching command to it, requesting a switch from off-grid operation mode to grid-connected operation mode. The energy storage converter adjusts its control strategy (e.g., restores grid synchronization control), and after completing the switch, it feeds back the grid-connected operation mode status information (e.g., "Operation Mode: Grid-connected").

[0073] Continuing with the above embodiment, the energy management system monitors the first communication status information of the grid-connected circuit breaker via 485 communication as "mains voltage 380V, frequency 50Hz, lasting 10 seconds" (determined as mains power restoration). The control energy management system sends a "shutdown" command to the energy storage converter, which stops its off-grid output and reports "Operating status: Shutdown". Subsequently, the energy storage control device sends a "mode switch: grid-connected" command (setting the mode register to 0x0001), and the energy storage converter loads the current loop control parameters in grid-connected mode (tracking the grid voltage phase), reporting "Operating mode: Grid-connected", and is in a grid-connected shutdown state.

[0074] Step 60: Based on the grid-connected operation mode status information, send a control command to the grid-connected circuit breaker, set the first digital output port of the energy management system to 0 and the second digital output port to 1, obtain the closing command, and control the grid-connected circuit breaker to perform the closing operation based on the closing command.

[0075] Furthermore, after acquiring the "grid-connected operation mode status information" of the energy storage converter, the energy storage control device sends a control command to the grid-connected circuit breaker through the energy management system: setting the first digital output port (DO1) to 0 and the second digital output port (DO2) to 1. Since the closing corresponding ports 1 and 7 in the control ports of the grid-connected circuit breaker, in this state, the output of DO2 (1) and the output of DO1 (0) will trigger the closing logic, forming a closing command, controlling the grid-connected circuit breaker to perform the closing operation and reconnect to the mains power.

[0076] Continuing with the above embodiment, after the energy storage converter reports "Operating Mode: Grid Connected", the energy storage control device controls the energy management system to set DO1 to 0 (low level) and DO2 to 1 (high level). This signal is transmitted to the control port of the grid-connected circuit breaker. Port 1 and port 7 connect the closing circuit due to the high-level signal of DO2. The grid-connected circuit breaker performs the closing operation, the mechanical contacts close, the electrical connection with the mains power is restored, and the "Closing Status: Closed" is reported via 485 communication.

[0077] Step 70: Based on the normal communication status information of the grid-connected circuit breaker, the status information of the grid-connected circuit breaker being in closed operation, the status information of the first digital output port outputting 0 and the second digital output port outputting 1, and the grid-connected operation mode status information of the energy storage converter, a start command is sent to the energy storage converter, and the energy storage converter is started and operated based on the start command.

[0078] Furthermore, the energy storage control device simultaneously monitors four conditions: 1. The communication status information of the grid-connected circuit breaker is "communication normal" (communication with the mains side is restored after closing); 2. The grid-connected circuit breaker reports "in closed operation state"; 3. The energy management system outputs DO1 0 and DO2 1 (maintaining the closed state); 4. The energy storage converter reports "grid-connected operation mode status information". When all four conditions are met, the energy storage control device sends a start command to the energy storage converter through the energy management system. The energy storage converter starts from the grid-connected shutdown state, enters the grid-connected operation mode, and participates in grid peak shaving or energy storage charging and discharging.

[0079] Continuing with the above embodiment, the energy storage control device monitors the following: 1. The grid-connected circuit breaker's 485 communication is normal (data refresh interval < 1 second); 2. The circuit breaker reports "Closed status: Closed"; 3. DO1 outputs 0, DO2 outputs 1 (closed status unchanged); 4. The energy storage converter reports "Operating mode: Grid-connected". Once these conditions are met, the control energy management system sends a "Start" command to the energy storage converter. The energy storage converter then starts its grid-connected inverter function, outputting active / reactive power according to the grid command, and reports "Operating status: Grid-connected operation".

[0080] This invention monitors the communication status information of the grid-connected circuit breaker to obtain the judgment result of mains power outage or restoration, providing an accurate trigger basis for subsequent grid-connected to off-grid switching, avoiding switching delays caused by detection logic defects. Based on the judgment result of mains power outage, the grid-connected circuit breaker is controlled to trip, directly cutting off the connection between the mains power and the energy storage system, fundamentally eliminating the safety hazard of energy storage power being fed back into the grid. Based on the tripping action signal, the energy storage converter is controlled to shut down, ensuring that the equipment is in a stable state before mode switching and avoiding power disturbance. Based on the shutdown status information, the energy storage converter is switched to off-grid mode to prepare for off-grid power supply. Based on the communication interruption information, tripping control status, and off-grid mode status, the energy storage converter is started to operate off-grid, ensuring the continuity of load power supply, thereby ensuring the reliable operation of the energy storage system in areas with unstable power grids.

[0081] In one embodiment, the energy storage system safety control method further includes load overload protection for the energy storage system during off-grid operation, specifically as described in steps 801 to 804:

[0082] Step 801: If it is determined that the load is in an overload state based on the real-time value of the load current at the output terminal of the energy storage converter, a derating command is sent to the energy storage converter to obtain a derating operation parameter, and the energy storage converter is controlled to reduce the output power based on the derating operation parameter.

[0083] Optionally, the energy storage control device collects the real-time load current value at the output of the energy storage converter (PCS) through sensors or an energy management system (EMS) and compares the real-time load current value with a preset load overload threshold (e.g., 120% of the rated load current). If the real-time load current value continuously exceeds the overload threshold (e.g., for 3 seconds), the load is determined to be in an overload state. At this time, the energy storage control device sends a derating command to the energy storage converter through the energy management system. This command includes derating operating parameters (e.g., limiting the output power to 80% of the rated power). After receiving the command, the energy storage converter adjusts its output power according to the derating operating parameters, reducing the power supplied to the load to alleviate the overload situation.

[0084] In one embodiment, the rated load current of the energy storage converter is 100A, and the preset overload threshold is 120A (i.e., 120% of the rated current). The energy storage control device collects a real-time load current value of 130A, and this state persists for 3 seconds, indicating an overload. The energy storage control device sends a derating command to the energy storage converter through the energy management system, setting the derating operation parameter to "output power limited to 80% of rated power." Upon receiving the command, the energy storage converter reduces its output power from the rated value (e.g., 100kW) to 80kW, corresponding to a reduction in output current from approximately 100A to approximately 80A (assuming stable voltage).

[0085] Step 802: Based on the operating status information after reducing the output power, collect the load current value after the first derating at the output terminal of the energy storage converter. If it is determined from the load current value after the first derating that the overload state has not been resolved, send a second derating command to the energy storage converter to obtain the second derating operating parameters, and control the energy storage converter to continue to reduce the output power based on the second derating operating parameters.

[0086] Furthermore, after the energy storage converter reduces its output power based on the primary derating parameters, the energy storage control device collects the post-derating load current value at the converter's output terminal via sensors or the energy management system and compares it again with the overload threshold. If the post-derating load current value still exceeds the overload threshold (e.g., for 2 seconds), the overload condition is determined to be unresolved. At this time, the energy storage control device sends a secondary derating command to the energy storage converter through the energy management system. This command includes secondary derating parameters (e.g., output power limited to 50% of rated power). Upon receiving the command, the energy storage converter further reduces its output power according to the secondary derating parameters to continue alleviating the overload situation.

[0087] Continuing with the above embodiment, after the energy storage converter reduces its output power to 80kW, the energy storage control device detects a load current value of 125A after the first derating, which still exceeds the overload threshold of 120A and persists for 2 seconds, indicating that the overload has not been relieved. The energy storage control device sends a second derating command to the energy storage converter, setting the second derating operating parameter to "output power limited to 50% of rated power". Upon receiving the command, the energy storage converter reduces its output power from 80kW to 50kW, corresponding to an output current reduction to approximately 50A.

[0088] Step 803: Based on the operating status information after further reducing the output power, collect the load current value after secondary derating at the output terminal of the energy storage converter. If it is determined from the result of the load current value after secondary derating that the overload state has not been resolved, send a status query command to the grid-connected circuit breaker to obtain the second communication status information of the grid-connected circuit breaker.

[0089] Furthermore, after the energy storage converter continues to reduce its output power based on the secondary derating operating parameters, the energy storage control device collects the secondary derating load current value at the output of the energy storage converter through sensors or the energy management system and compares it with the overload threshold. If the secondary derating load current value still exceeds the overload threshold (e.g., for 1 second), it is determined that the load overload state has not been resolved. At this time, the energy storage control device sends a status query command to the grid-connected circuit breaker (NM2LC residual current protection circuit breaker) through the energy management system (via the 485 communication line, corresponding to auxiliary ports 485A (port 4) and 485B (port 5)) to obtain the second communication status information of the grid-connected circuit breaker, which includes whether the mains power supply has been restored and the current opening and closing status of the circuit breaker.

[0090] Continuing with the above embodiment, after the energy storage converter reduces its output power to 50kW, the energy storage control device collects a load current value of 122A after the secondary derating, which still exceeds the overload threshold of 120A and lasts for 1 second, thus determining that the overload has not been relieved. The energy storage control device sends a status query command to the grid-connected circuit breaker via 485 communication (such as Modbus function code 0x03 to read the status register), and obtains the second communication status information as "Main power has been restored (voltage 380V, frequency 50Hz), the current status of the circuit breaker is open".

[0091] Step 804: Control the operation of the energy storage converter based on the second communication status information.

[0092] Furthermore, the energy storage control device controls the operation of the energy storage converter through the second communication status information, specifically as described in steps 8041 to 8043.

[0093] This invention gradually reduces the output power of the energy storage converter through two derating operations, attempting to alleviate overload without interrupting power supply. If the overload is still not relieved after derating, the status of the grid-connected circuit breaker is checked to determine whether the mains power is available. Based on the mains power status, the system chooses to restore grid-connected power supply or perform an emergency shutdown, maximizing the continuous power supply to the off-grid load and preventing damage to the energy storage converter due to long-term overload. At the same time, it achieves a smooth transition when the mains power is restored, improving the safety and reliability of the off-grid operation of the energy storage system.

[0094] In one embodiment, steps 8041 to 8043 include:

[0095] Step 8041: If it is determined based on the second communication status information that the mains power has not been restored, then a load cut-off command is sent to the load distribution controller in the energy storage system to obtain the priority load cut-off, and the load distribution controller is controlled to cut off the power supply circuit of non-critical loads based on the priority load cut-off.

[0096] Optionally, based on the second communication status information, if the mains power supply has not been restored (e.g., communication information shows that the mains voltage and frequency are still within an abnormal range), the energy storage control device sends a load shedding command to the load distribution controller within the energy storage system. This command includes a preset list of priority loads to be shedding (e.g., non-critical loads such as lighting and air conditioning, whose power supply priority is lower than critical loads such as medical equipment and emergency communication equipment). Upon receiving the command, the load distribution controller cuts off the power supply circuits of non-critical loads according to the priority load shedding list to reduce the total load current and alleviate the overload condition.

[0097] Continuing with the above embodiment, the second communication status information is "Main power not restored (voltage 0V), circuit breaker tripped." The energy storage control device determines that non-critical loads need to be cut off. The energy storage control device sends a load cut-off command to the load distribution controller, specifying the priority loads to be cut off as "office lighting (load current 20A) and air conditioning system (load current 30A)." After receiving the command, the load distribution controller disconnects the power supply switch of the corresponding non-critical load, cutting off its power supply circuit, reducing the total load demand by 50A.

[0098] Step 8042: If the load overload state is determined to be relieved based on the load current value at the output terminal of the energy storage converter after the load is disconnected, which is collected from the power supply status information after the non-critical load is disconnected, then a stable operation command is sent to the energy storage converter to obtain stable operation parameters, and the energy storage converter is controlled to maintain the current output power operation based on the stable operation parameters.

[0099] Furthermore, after the load distribution controller disconnects the power supply circuit for non-critical loads, the energy storage control device collects the load current value at the output of the energy storage converter (PCS) after the load is disconnected via sensors or the energy management system (EMS), and compares this value with an overload threshold (such as 120% of the rated load current). If the load current value drops below the overload threshold after the load is disconnected (e.g., for 1 second), the overload condition is determined to be resolved. At this time, the energy storage control device sends a stable operation command to the energy storage converter, which includes stable operation parameters (such as maintaining the current secondary derating output power, i.e., 50% of the rated power), controlling the energy storage converter to continue operating at the current output power to ensure a stable power supply to critical loads.

[0100] Continuing with the above embodiment, after disconnecting the non-critical load, the load current value after load removal is 70A (the original load current after secondary derating was 122A, which decreased to 70A after disconnecting the 50A non-critical load), which is lower than the overload threshold of 120A and remains so for 1 second, indicating that the overload has been relieved. The energy storage control device sends a stable operation command to the energy storage converter, setting the stable operation parameter to "maintain the current output power of 50kW". The energy storage converter maintains a 50kW output, continuously supplying power to the critical load (such as medical monitoring equipment, with a load current of 70A).

[0101] Step 8043: If it is determined that the overload condition has not been resolved, an emergency stop command is sent to the energy storage converter, and the energy storage converter is controlled to stop operating based on the emergency stop command. A trip holding command is sent to the grid-connected circuit breaker, and the grid-connected circuit breaker is controlled to maintain the trip state based on the trip holding command.

[0102] Furthermore, if the load current value collected after the load distribution controller disconnects the non-critical load continues to exceed the overload threshold (e.g., for 1 second), the energy storage control device determines that the overload state has not been resolved (indicating that the remaining load is still a critical load but the total power exceeds the capacity of the energy storage converter). At this time, the energy storage control device sends an emergency shutdown command to the energy storage converter, controlling it to immediately stop output power (cutting off the internal power circuit to avoid long-term overload damage); at the same time, it sends a trip holding command to the grid-connected circuit breaker (NM2LC residual current protection circuit breaker), maintaining the state of the first digital output port (DO1) as 1 and the second digital output port (DO2) as 0 through the energy management system, ensuring that the grid-connected circuit breaker continues to remain in the tripped state, avoiding abnormal connection with the mains power side (not restored).

[0103] Continuing with the above embodiment, after disconnecting the non-critical load, the energy storage control device detects a load current value of 130A after the load is disconnected (still exceeding the 120A overload threshold) for 1 second, indicating that the overload has not been relieved. The energy storage control device sends an emergency shutdown command to the energy storage converter, which immediately disconnects its output and reports "Operating Status: Emergency Shutdown"; simultaneously, it sends a tripping and holding command to the grid-connected circuit breaker, and the energy management system maintains DO1=1 and DO2=0 to ensure that the circuit breaker remains open and prevents abnormal closing.

[0104] This invention reduces total demand by cutting off non-critical loads and prioritizes power supply to critical loads. If the overload is relieved, the output is stabilized to maintain critical services. If the overload continues, an emergency shutdown is initiated and the circuit breaker is kept open to avoid equipment damage and safety risks. This maximizes the continuity of power supply to critical loads when off-grid, and also avoids failures of energy storage devices due to overload through hierarchical control, thereby improving the safety and reliability of the energy storage system under extreme load conditions.

[0105] In one embodiment, the energy storage system safety control method further includes load balancing control when multiple energy storage cabinets are operating in parallel, specifically as described in steps 805 to 808:

[0106] Step 805: Determine the load distribution status of each energy storage converter based on the output power and current data of each energy storage converter, and calculate the average output power of all energy storage converters based on the load distribution status of each energy storage converter to obtain the first average output power value.

[0107] Optionally, the energy storage control device collects real-time output power and current data from multiple energy storage converters (PCS) via an energy management system (EMS) (the output power of each energy storage converter is denoted as P1, P2, ..., Pn, where n is the number of energy storage converters). Based on this data, the load distribution status of each energy storage converter (i.e., the proportion of the total load borne by a single unit) is determined. Subsequently, the energy storage control device calculates the arithmetic mean of the output power of all energy storage converters, i.e., the first average output power value (the calculation formula is: first average output power value = (P1 + P2 + ... + Pn) / n), as a benchmark value for judging whether the load is balanced.

[0108] In one embodiment, the energy storage system has three energy storage converters operating in parallel, with the collected output power being: 120kW for energy storage converter 1, 80kW for energy storage converter 2, and 100kW for energy storage converter 3. The energy storage control device determines the load distribution of the three energy storage converters to be 40%, 26.7%, and 33.3% of the total load (300kW), respectively. The first average output power is calculated to be (120+80+100) / 3 = 100kW.

[0109] Step 806: If the output power of each energy storage converter is unbalanced based on the first average output power value, then select the energy storage converter with an output power higher than the first average output power value to obtain the high-load energy storage converter, and send a power reduction command to the high-load energy storage converter.

[0110] Furthermore, the energy storage control device compares the output power of each energy storage converter with the first average output power value. If the difference between the output power of a single converter and the first average output power value exceeds a preset equalization threshold (e.g., ±10% of the first average output power value), it is determined that the output power of all energy storage converters is unbalanced. At this time, energy storage converters with output power higher than the first average output power value are selected, defined as high-load energy storage converters, and a power reduction command is sent to them (the reduction amount is 50% of the difference between the current power and the first average output power value) to reduce their output power and move closer to the balanced state.

[0111] Continuing with the above embodiment, the first average output power value is 100kW, and the preset equalization threshold is ±10kW (i.e., 100kW ± 10%). The energy storage control device determines that: the difference between the 120kW of energy storage converter 1 and the average value is +20kW (exceeding 10kW), the difference between the 80kW of energy storage converter 2 and the average value is -20kW (exceeding -10kW), and the difference between the 100kW of energy storage converter 3 and the average value is 0 (within the threshold). Therefore, it is determined that the output power is unbalanced. The high-load energy storage converter is selected as energy storage converter 1, and a power reduction command is sent to it, with a reduction amount of 50% of the difference (i.e., 20kW * 50% = 10kW), and the target power of the command is 110kW.

[0112] Step 807: If the adjusted output power value of the high-load energy storage converter, collected based on the operating status information after the first power reduction command, is not close to the first average output power value, then a second power reduction command is sent to the high-load energy storage converter to obtain the second reduction parameters, and the high-load energy storage converter is controlled to continue to reduce the output power based on the second reduction parameters.

[0113] Furthermore, after the high-load energy storage converter executes a power reduction command, the energy storage control device collects the adjusted output power value through the energy management system and compares this value with the first average output power value. If the difference between the adjusted output power value and the first average output power value still exceeds the equilibrium threshold (e.g., still greater than 10%), it is determined that the output power value is not close to the first average output power value. At this time, a second power reduction command is sent to the high-load energy storage converter, including a second reduction parameter (e.g., reducing it to equal to the first average output power value), controlling it to continue reducing the output power and further adjust towards the equilibrium state.

[0114] Continuing with the above embodiment, after the energy storage converter 1 executes a power reduction command, its output power is adjusted to 110kW, which is +10kW different from the first average output power value of 100kW (still equal to the equalization threshold of 10kW, thus not close enough). The energy storage control device sends it a second power reduction command, with the parameter "output power adjusted to 100kW". After receiving the command, the energy storage converter 1 reduces its output power from 110kW to 100kW.

[0115] Step 808: Based on the operating status information after further reducing the output power, select energy storage converters with output power lower than the first average output power value to obtain low-load energy storage converters, and control the operation of energy storage converters based on low-load energy storage converters.

[0116] Furthermore, after the high-load energy storage converter continues to reduce its output power based on the secondary down-adjustment parameters, the energy storage control device collects the output power of all energy storage converters through the energy management system and filters out the low-load energy storage converters whose output power is lower than the first average output power value. Further, the energy storage control device controls the operation of the energy storage converters based on the low-load energy storage converters, as detailed in steps 8081 to 8083.

[0117] This invention gradually adjusts the output power of high-load energy storage converters and specifically increases the output power of low-load energy storage converters, ultimately making the output power of all energy storage converters more consistent. This avoids the risk of shortened lifespan or failure of a single device due to long-term overload, while improving the overall system's operating efficiency and stability, ensuring that multi-machine parallel systems can work reliably in both off-grid and grid-connected scenarios.

[0118] In one embodiment, steps 8081 to 8083 include:

[0119] Step 8081: Send a power increase command to the low-load energy storage converter. If the adjusted output power value of the low-load energy storage converter, collected based on the operating status information after the first power increase command, is not close to the first average output power value, then send a second power increase command based on the low-load energy storage converter to obtain the second increase parameters. Based on the second increase parameters, control the low-load energy storage converter to continue to increase the output power.

[0120] Optionally, the energy storage control device sends a power increase command to the low-load energy storage converter selected in step 808 (with the adjustment amount being 50% of the difference between the current power and the first average output power value). After the low-load energy storage converter executes the command, the energy storage control device collects its adjusted output power value through the energy management system (EMS) and compares it with the first average output power value. If the difference between the adjusted output power value and the first average output power value still exceeds a preset equalization threshold (such as ±10% of the first average output power value), it is determined that the target value is not approached. At this time, the energy storage control device sends a second power increase command to the low-load energy storage converter, including a second increase parameter (such as directly increasing to the first average output power value), controlling it to continue to increase its output power and narrow the gap with the average value.

[0121] Continuing with the above embodiment, the low-load energy storage converter is energy storage converter 2 with an output power of 80kW, a first average output power value of 100kW, and an equalization threshold of ±10kW. The energy storage control device first sends a power increase command, with an increase of 50% of the difference (20kW * 50% = 10kW), and a target power of 90kW. After execution, the increased output power value is collected as 90kW, and the difference from 100kW is -10kW (equal to the threshold, determined not to be close). The energy storage control device sends a second power increase command, with the second increase parameter being "output power adjusted to 100kW", and energy storage converter 2 increases the power from 90kW to 100kW.

[0122] Step 8082: Calculate the second average output power value based on the balanced adjustment output power values ​​of all energy storage converters collected from the operating status information after the continued increase in output power.

[0123] Furthermore, after the low-load energy storage converter continues to increase its output power based on the secondary adjustment parameters, the energy storage control device collects the balanced output power values ​​of all energy storage converters (i.e., the current actual output power of each unit) through the energy management system. Subsequently, the arithmetic mean of these power values ​​is calculated to obtain the second average output power value (second average output power value = (adjusted P1 + adjusted P2 + ... + adjusted Pn) / n, where n is the number of energy storage converters), which serves as the benchmark for finally judging the load balance status.

[0124] Continuing with the above embodiment, the output power values ​​of the three energy storage converters after equalization adjustment are as follows: Energy storage converter 1 is 100kW, energy storage converter 2 is 100kW, and energy storage converter 3 is 100kW. The energy storage control device calculates the second average output power value as (100+100+100) / 3=100kW.

[0125] Step 8083: Determine whether the deviation between the output power of each energy storage converter and the second average output power value is within the allowable range. If it is within the allowable range, send an equalization maintenance command to all energy storage converters, and control all energy storage converters to maintain the current output power based on the equalization maintenance command.

[0126] Furthermore, the energy storage control device compares the balanced output power value of each energy storage converter with the second average output power value, and calculates the deviation of the single unit's power from the average value (deviation = |single unit power - second average output power value|). If all deviations are less than or equal to a preset allowable range (e.g., ±5% of the second average output power value), the load balancing state is deemed satisfactory. At this time, the energy storage control device sends a balance maintenance command to all energy storage converters, which includes parameters for maintaining the current output power, controlling all energy storage converters to maintain the current power operation and stabilize the load distribution state. Continuing with the above embodiment, the second average output power value is 100kW, and the allowable range is ±5kW (i.e., 100kW ±5%). The energy storage control device determines that the output power of all three energy storage converters is 100kW, the deviation from the average value is 0, and all are within the allowable range. Therefore, it sends a balance maintenance command to all energy storage converters with the parameter "maintain the current 100kW output power", and all energy storage converters maintain this power operation, achieving stable load balancing.

[0127] This invention, through a gradual increase in the output power of low-load devices and combined with a secondary average power verification, ensures that the power deviation of all devices is controlled within the allowable range. Ultimately, by maintaining a stable and balanced command state, it avoids resource waste caused by excessively light loads on a single device, while preventing power fluctuations during the adjustment process. This improves the operating efficiency, stability, and equipment lifespan of the multi-machine parallel system, and ensures the reliable operation of the energy storage system under complex operating conditions.

[0128] In one embodiment, the energy storage system safety control method further includes inrush current suppression during the off-grid to grid-connected transition of the energy storage system, specifically as described in steps 809 to 813:

[0129] Step 809: Based on the start-up preparation signal of the current suppression circuit, the current suppression module is controlled to enter the working state, and a soft-start command is sent to the energy storage converter based on the status information of the current suppression module after entering the working state, so as to obtain the soft-start voltage rise rate parameter.

[0130] Optionally, when the energy storage system is preparing to switch from off-grid operation mode to grid-connected operation mode, the energy storage control device first acquires the start-up preparation signal of the current suppression circuit (this signal indicates that the hardware circuit of the current suppression circuit is ready, such as the relay contacts being in normal condition and the current-limiting resistor being fault-free). Based on this signal, the energy storage control device controls the current suppression module to enter the working state (e.g., closing the access switch of the current suppression module, connecting it in series with the circuit between the output of the energy storage converter and the grid). After the current suppression module replies with the information that it has entered the working state, the energy storage control device sends a soft-start command to the energy storage converter. This command includes a soft-start voltage rise rate parameter (e.g., the voltage rises from the current off-grid output voltage at a rate of 0.5V / ms to the grid voltage value) to prepare for a smooth voltage rise.

[0131] In one embodiment, when the energy storage system is operating off-grid, the output voltage is 370V, the grid voltage is 380V, and the current suppression circuit provides a "start-up preparation signal: ready". The energy storage control device controls the current suppression module to close the connection switch, connecting it in series into the circuit, and provides a "working status: connected" feedback. Subsequently, the energy storage control device sends a soft-start command to the energy storage converter, with the soft-start voltage rise rate parameter set to "0.5V / ms", meaning it rises from 370V to 380V at a rate of 0.5V per millisecond.

[0132] Step 810: Control the energy storage converter to increase the output voltage at a set rate based on the soft-start voltage rise rate parameter.

[0133] Furthermore, based on the soft-start voltage rise rate parameter, the energy storage control device controls the output voltage of the energy storage converter to gradually increase at a set rate. During the increase, the energy storage converter adjusts the output in real time through an internal voltage regulation circuit (such as a PI regulator) to ensure that the voltage change rate remains stable within the set parameter range, avoiding inrush current caused by voltage surges. The energy storage control device monitors the output voltage in real time through a voltage sensor to confirm that the voltage rise process meets the rate requirements. Continuing with the above embodiment, the energy storage converter increases the output voltage at a rate of 0.5V / ms. The initial voltage is 370V, rising to 375V after 10ms, and to 380V after 20ms. The voltage rises smoothly throughout the process without any sudden changes. The energy storage control device, through the voltage sensor, detects that the voltage change curve is consistent with the set rate, and determines that the voltage rise process is normal.

[0134] Step 811: Based on the voltage data after the output voltage is increased, a pre-charge current acquisition command is sent to the current detection module to obtain the pre-charge current data at the output of the energy storage converter, and based on the pre-charge current data, it is determined whether the pre-charge current exceeds the inrush current threshold.

[0135] Furthermore, after the output voltage of the energy storage converter is increased to near the grid voltage (e.g., reaching more than 95% of the grid voltage), the energy storage control device sends a pre-charge current acquisition command to the current detection module (this module is used to detect the pre-charge loop current between the energy storage converter output and the grid). Upon receiving the command, the current detection module acquires and feeds back the pre-charge current data (e.g., real-time current value) at the energy storage converter output. The energy storage control device compares this data with a preset inrush current threshold (e.g., 150% of the rated current of the energy storage converter) to determine whether the pre-charge current exceeds the threshold, thereby assessing the existence of an inrush risk.

[0136] Continuing with the above embodiment, after the energy storage converter output voltage rises to 380V (consistent with the grid voltage), the energy storage control device sends a pre-charge current acquisition command to the current detection module. The current detection module returns the pre-charge current data as 180A. The rated current of the energy storage converter is 100A, and the preset inrush current threshold is 150A (100A*150%). Since 180A > 150A, it is determined that the pre-charge current exceeds the inrush current threshold.

[0137] Step 812: If the pre-charge current exceeds the impact current threshold based on the judgment result, the current limiting resistor access parameters are obtained by sending a current limiting adjustment command to the current suppression module, and the current limiting resistor access parameters are used to control the current suppression module to connect a current limiting resistor with a larger resistance value.

[0138] Furthermore, if the pre-charge current exceeds the inrush current threshold, the energy storage control device sends a current-limiting adjustment command to the current suppression module. This command includes the current-limiting resistor connection parameters (e.g., switching from the currently connected 5Ω current-limiting resistor to a 10Ω resistor with a larger resistance). Upon receiving the command, the current suppression module switches the connected current-limiting resistor via an internal relay, increasing the total circuit resistance and using Ohm's law (current = voltage difference / resistance) to reduce the pre-charge current and suppress the inrush. Continuing with the above embodiment, if the pre-charge current of 180A exceeds the 150A threshold, the energy storage control device sends a current-limiting adjustment command to the current suppression module, setting the current-limiting resistor connection parameters to "connect a 10Ω current-limiting resistor" (the original connection resistance was 5Ω). After the current suppression module switches the resistor, the total circuit resistance increases, and the pre-charge current decreases due to the increased resistance.

[0139] Step 813: Based on the status information after connecting a larger resistance current limiting resistor, a pre-charge current acquisition command is sent to the current detection module to obtain the adjusted pre-charge current data, and the operation of the energy storage converter is controlled based on the adjusted pre-charge current data.

[0140] Furthermore, after the current suppression module connects to a current-limiting resistor with a larger resistance value, it sends a "resistance has been switched" status information back to the energy storage control device. Based on this information, the energy storage control device sends a pre-charge current acquisition command to the current detection module again to obtain the adjusted pre-charge current data, and controls the operation of the energy storage converter according to the adjusted pre-charge current data, as in steps 8131 to 8134.

[0141] This invention, through soft-start control, ensures a smooth voltage rise. Combined with current detection and dynamic adjustment of the current-limiting resistor, it guarantees that the pre-charge current is always below the impact threshold, avoiding the impact damage of sudden current changes to the energy storage converter, grid-connected circuit breaker, and power grid. This ensures the electrical safety of the off-grid to grid-connected process, improves the reliability of the energy storage system's connection to the power grid, and reduces equipment losses and grid disturbances during the switching process.

[0142] In one embodiment, steps 8131 to 8134 include:

[0143] Step 8131: If the pre-charge current drops below the inrush current threshold based on the adjusted pre-charge current data, a closing preparation command is sent to the grid-connected circuit breaker to obtain the circuit status data before closing, and the grid-connected circuit is judged to have the closing conditions based on the circuit status data.

[0144] Optionally, based on the adjusted pre-charge current data obtained in step 813, if the energy storage control device determines that the pre-charge current has dropped below the inrush current threshold (e.g., 120A < 150A), it sends a closing preparation command to the grid-connected circuit breaker (NM2LC residual current protection circuit breaker). This command triggers the grid-connected circuit breaker to perform a self-check of its own status and circuit parameters, and feeds back the circuit status data before closing (including whether the mechanical status of the circuit breaker is normal, whether the difference between the output voltage of the energy storage converter and the grid voltage is within the allowable range (e.g., ±5V), and whether there is a short circuit signal in the circuit). The energy storage control device verifies these data. If all parameters meet the preset standards (e.g., voltage difference ≤ 5V, no short circuit signal, normal mechanical status), it determines that the grid-connected circuit meets the closing conditions.

[0145] In one embodiment, the adjusted pre-charge current data is 120A (below the 150A threshold), and a closing preparation command is sent to the grid-connected circuit breaker. The circuit breaker feeds back the circuit status data before closing: "Mechanical status: Ready; Energy storage output voltage 380V, grid voltage 381V, voltage difference 1V; No short circuit signal." After verification, it is determined that: the voltage difference 1V ≤ 5V, there is no abnormal signal, the mechanical status is normal, therefore the grid-connected circuit meets the closing conditions.

[0146] Step 8132: If the closing conditions are met, a slow closing command is sent to the grid-connected circuit breaker to obtain the closing speed parameters, and the grid-connected circuit breaker is controlled to slowly perform the closing operation based on the closing speed parameters.

[0147] Furthermore, if the grid-connected circuit is determined to meet the closing conditions, a slow closing command is sent to the grid-connected circuit breaker. This command includes closing speed parameters (e.g., the closing time is set to 50ms, meaning the process from the open state to full closing lasts 50ms, instead of the conventional 10ms, to reduce the current surge at the moment of closing). After receiving the command, the grid-connected circuit breaker controls its internal mechanical structure to move slowly according to the set closing speed parameters, causing the main contacts to gradually contact, reducing the inrush current caused by the voltage phase difference due to the instantaneous closing of the contacts.

[0148] Continuing with the above embodiment, the energy storage control device sends a slow closing command to the grid-connected circuit breaker, with the closing speed parameter set to "closing time 50ms". The main contacts of the grid-connected circuit breaker start from the open state and move at a uniform speed, fully closing after 50ms, thus avoiding arcing and current spikes that may occur during rapid closing.

[0149] Step 8133: Based on the operating status information after slow closing, a grid-connected inrush current acquisition command is sent to the current detection module to obtain the inrush current data at the moment of closing. If it is determined based on the inrush current data at the moment of closing that the inrush current is within the allowable range, a current limiting release command is sent to the current suppression module, and the current limiting release command is used to control the current suppression module to gradually disconnect the current limiting resistor.

[0150] Furthermore, after the grid-connected circuit breaker completes the slow closing operation, it sends a "closing complete" status message to the energy storage control device. Based on this message, the energy storage control device sends a grid-connected inrush current acquisition command to the current detection module to obtain the inrush current data at the moment of closing (e.g., within 10ms after closing). If this data is lower than the preset allowable range (e.g., 120% of the rated current of the energy storage converter), the inrush current is determined to be within the safe range. At this time, the energy storage control device sends a current limiting release command to the current suppression module, controlling it to gradually disconnect the connected current limiting resistors via relays (e.g., disconnecting part of the resistor first, and disconnecting the remaining resistor after a 20ms interval) to avoid current fluctuations caused by sudden resistor disconnection. Continuing with the above embodiment, after the grid-connected circuit breaker closes slowly, the current detection module reports an inrush current data of 110A at the moment of closing (the rated current of the energy storage converter is 100A, and the allowable range is 120A), which is determined to be within the allowable range. Send a current limiting release command to the current suppression module to control it to first cut off the 5Ω current limiting resistor (keeping 5Ω), and then cut off the remaining 5Ω resistor after 20ms, and finally completely cut off the current limiting resistor, and the loop resistance returns to the normal level.

[0151] Step 8134: Based on the status information after gradually removing the current-limiting resistor, a power recovery command is sent to the energy storage converter to obtain the power recovery rate parameter. Based on the power recovery rate parameter, the energy storage converter is controlled to increase the output power at a set rate until normal grid-connected power operation is restored.

[0152] Furthermore, after the current suppression module completely disconnects the current-limiting resistor, it sends a "current limiting release complete" status message to the energy storage control device. Based on this message, the energy storage control device sends a power recovery command to the energy storage converter, which includes a power recovery rate parameter (e.g., increasing output power at a rate of 10kW / s). Upon receiving the command, the energy storage converter gradually increases its output power at the set rate, from the current soft-start low-power state (e.g., 20kW) to the normal grid-connected operating power (e.g., 100kW), avoiding power surges that could disrupt the grid. Continuing with the above embodiment, after the current-limiting resistor is completely disconnected, the energy storage control device sends a power recovery command to the energy storage converter, with the power recovery rate parameter set to "10kW / s". The energy storage converter starts from the current output of 20kW, increasing to 30kW after 1 second, 40kW after 2 seconds, and so on, until reaching 100kW after 8 seconds, achieving normal grid-connected power and stable operation.

[0153] The embodiments of the present invention avoid current surges throughout the entire process, from pre-closing status confirmation to slow control of the closing action, to post-closing current monitoring and parameter recovery. This ensures electrical safety during grid connection and subsequent power recovery, reduces impact damage to energy storage converters, grid-connected circuit breakers, and the power grid, achieves a smooth transition from off-grid to grid-connected operation, and improves the reliability and stability of the coordinated operation of the energy storage system and the power grid.

[0154] Furthermore, the safety control device for an energy storage system based on a residual current circuit breaker provided by the present invention will be described below. The safety control device for an energy storage system based on a residual current circuit breaker described below can be referred to in correspondence with the safety control method for an energy storage system based on a residual current circuit breaker described above. Optionally, referencing... Figure 2 , Figure 2 This is a schematic diagram of the structure of the energy storage system safety control device based on the residual current circuit breaker provided by the present invention. The energy storage system safety control device based on the residual current circuit breaker includes:

[0155] The tripping control module 210 is used to send a control command to the grid-connected circuit breaker if it is determined that the mains power has been cut off based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system. The control module sets the first digital output port of the energy management system to 1 and the second digital output port to 0 to obtain the tripping command, and controls the grid-connected circuit breaker to perform the tripping operation based on the tripping command.

[0156] The first energy storage control module 220 is used to send a shutdown command to the energy storage converter based on the action signal of the grid-connected circuit breaker performing the tripping operation, and control the energy storage converter to stop running based on the shutdown command;

[0157] The mode switching module 230 is used to send a mode switching command to the energy storage converter based on the status information of the energy storage converter stopping operation, so as to switch the operation mode of the energy storage converter from the grid-connected operation mode to the off-grid operation mode and obtain the off-grid operation mode status information of the energy storage converter.

[0158] The second energy storage control module 240 is used to send a start command to the energy storage converter based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, so as to control the energy storage converter to start and run based on the start command.

[0159] This invention monitors the communication status information of the grid-connected circuit breaker to obtain the judgment result of mains power outage or restoration, providing an accurate trigger basis for subsequent grid-connected to off-grid switching, avoiding switching delays caused by detection logic defects. Based on the judgment result of mains power outage, the grid-connected circuit breaker is controlled to trip, directly cutting off the connection between the mains power and the energy storage system, fundamentally eliminating the safety hazard of energy storage power being fed back into the grid. Based on the tripping action signal, the energy storage converter is controlled to shut down, ensuring that the equipment is in a stable state before mode switching and avoiding power disturbance. Based on the shutdown status information, the energy storage converter is switched to off-grid mode to prepare for off-grid power supply. Based on the communication interruption information, tripping control status, and off-grid mode status, the energy storage converter is started to operate off-grid, ensuring the continuity of load power supply, thereby ensuring the reliable operation of the energy storage system in areas with unstable power grids.

[0160] Please see Figure 3 , Figure 3 A schematic diagram illustrating an embodiment of the electronic device provided in this invention. For example... Figure 3 As shown, this embodiment of the invention provides an electronic device 300, including a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and executable on the processor 320. When the processor 320 executes the computer program 311, it performs the following steps:

[0161] If a power outage is determined based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system, a control command is sent to the grid-connected circuit breaker to set the first digital output port of the energy management system to 1 and the second digital output port to 0, thereby obtaining a tripping command, and the grid-connected circuit breaker is controlled to perform a tripping operation based on the tripping command.

[0162] Based on the action signal of the grid-connected circuit breaker performing the tripping operation, a shutdown command is sent to the energy storage converter, and the energy storage converter is controlled to stop operation based on the shutdown command;

[0163] Based on the status information of the energy storage converter stopping operation, a mode switching command is sent to the energy storage converter to switch the operation mode of the energy storage converter from grid-connected operation mode to off-grid operation mode, and the off-grid operation mode status information of the energy storage converter is obtained.

[0164] Based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, a start command is sent to the energy storage converter to control the energy storage converter to start operation based on the start command.

[0165] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0166] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0167] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0168] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0169] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0170] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0171] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A safety control method for an energy storage system based on a residual current circuit breaker, characterized in that, include: use If a power outage is determined based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system, a control command is sent to the grid-connected circuit breaker to set the first digital output port of the energy management system to 1 and the second digital output port to 0, thereby obtaining a tripping command. Based on the tripping command, the grid-connected circuit breaker is controlled to perform a tripping operation. The grid-connected circuit breaker is a residual current protection circuit breaker. Based on the action signal of the grid-connected circuit breaker performing the tripping operation, a shutdown command is sent to the energy storage converter, and the energy storage converter is controlled to stop operation based on the shutdown command; Based on the status information of the energy storage converter stopping operation, a mode switching command is sent to the energy storage converter to switch the operation mode of the energy storage converter from grid-connected operation mode to off-grid operation mode, thereby obtaining the off-grid operation mode status information of the energy storage converter. Based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, a start command is sent to the energy storage converter to control the energy storage converter to start operation based on the start command. The method further includes: The start-up preparation signal based on the current suppression circuit controls the current suppression module to enter the working state, and sends a soft-start command to the energy storage converter based on the status information of the current suppression module after entering the working state, thereby obtaining the soft-start voltage rise rate parameter. Based on the soft-start voltage rise rate parameter, the energy storage converter is controlled to increase the output voltage at a set rate. Based on the voltage data after the output voltage is increased, a pre-charge current acquisition command is sent to the current detection module to obtain the pre-charge current data at the output of the energy storage converter, and based on the pre-charge current data, it is determined whether the pre-charge current exceeds the inrush current threshold. If the pre-charge current exceeds the inrush current threshold based on the judgment result, the current limiting resistor access parameters are obtained by sending a current limiting adjustment command to the current suppression module, and the current limiting resistor access parameters are used to control the current suppression module to connect a current limiting resistor with a larger resistance value. Based on the status information after connecting a larger resistance current limiting resistor, a pre-charge current acquisition command is sent to the current detection module to obtain the adjusted pre-charge current data, and the operation of the energy storage converter is controlled based on the adjusted pre-charge current data. Controlling the operation of the energy storage converter based on the adjusted pre-charge current data includes: If, based on the adjusted pre-charge current data, it is determined that the pre-charge current has dropped below the inrush current threshold, a closing preparation command is sent to the grid-connected circuit breaker to obtain the circuit status data before closing, and it is determined whether the grid-connected circuit has the conditions for closing based on the circuit status data. If the closing conditions are met, a slow closing command is sent to the grid-connected circuit breaker to obtain the closing speed parameters, and the grid-connected circuit breaker is controlled to slowly perform the closing operation based on the closing speed parameters. Based on the operating status information after slow closing, a grid-connected inrush current acquisition command is sent to the current detection module to obtain the inrush current data at the moment of closing. If it is determined based on the inrush current data at the moment of closing that the inrush current is within the allowable range, a current limiting release command is sent to the current suppression module, and the current limiting release command is used to control the current suppression module to gradually disconnect the current limiting resistor. Based on the status information after gradually removing the current-limiting resistor, a power recovery command is sent to the energy storage converter to obtain the power recovery rate parameter. Based on the power recovery rate parameter, the energy storage converter is controlled to increase the output power at a set rate until it returns to normal grid-connected power operation.

2. The safety control method for an energy storage system based on a residual current circuit breaker according to claim 1, characterized in that, The method further includes: If it is determined that the load is in an overload state based on the real-time value of the load current at the output terminal of the energy storage converter, a derating command is sent to the energy storage converter to obtain a derating operation parameter, and the energy storage converter is controlled to reduce the output power based on the derating operation parameter. Based on the operating status information after reducing the output power, the load current value after the first derating at the output terminal of the energy storage converter is collected. If it is determined that the overload state has not been relieved based on the load current value after the first derating, a second derating command is sent to the energy storage converter to obtain the second derating operating parameters, and the energy storage converter is controlled to continue to reduce the output power based on the second derating operating parameters. Based on the operating status information after further reducing the output power, the load current value after the second derating at the output terminal of the energy storage converter is collected. If it is determined from the result of the load current value after the second derating that the overload state has not been relieved, a status query command is sent to the grid-connected circuit breaker to obtain the second communication status information of the grid-connected circuit breaker. The operation of the energy storage converter is controlled based on the second communication status information.

3. The safety control method for an energy storage system based on a residual current circuit breaker according to claim 2, characterized in that, Controlling the operation of the energy storage converter based on the second communication status information includes: If it is determined based on the second communication status information that the mains power has not been restored, then a load shedding command is sent to the load distribution controller in the energy storage system to obtain the priority load shedding, and the load distribution controller is controlled to cut off the power supply circuit of non-critical loads based on the priority load shedding. If the load overload condition is determined to be resolved based on the load current value at the output terminal of the energy storage converter after the load is disconnected, which is collected from the power supply status information after the non-critical load is disconnected, then a stable operation command is sent to the energy storage converter to obtain stable operation parameters, and the energy storage converter is controlled to maintain the current output power operation based on the stable operation parameters. If it is determined that the overload condition has not been resolved, an emergency stop command is sent to the energy storage converter, and the energy storage converter is controlled to stop operating based on the emergency stop command. A trip hold command is sent to the grid-connected circuit breaker, and the grid-connected circuit breaker is controlled to maintain the trip state based on the trip hold command.

4. The safety control method for an energy storage system based on a residual current circuit breaker according to claim 1, characterized in that, The method further includes: The load distribution status of each energy storage converter is determined based on the output power and current data of each energy storage converter, and the average output power of all energy storage converters is calculated based on the load distribution status of each energy storage converter to obtain the first average output power value. If it is determined that the output power of each energy storage converter is unbalanced based on the first average output power value, then the energy storage converter with an output power higher than the first average output power value is selected to obtain the high-load energy storage converter, and a power reduction command is sent to the high-load energy storage converter. If the adjusted output power value of the high-load energy storage converter, obtained from the operating status information collected after the first power reduction command, is not close to the first average output power value, a second power reduction command is sent to the high-load energy storage converter to obtain the second reduction parameters, and the high-load energy storage converter is controlled to continue to reduce the output power based on the second reduction parameters. Based on the operating status information after further reducing the output power, energy storage converters with output power lower than the first average output power value are selected to obtain low-load energy storage converters, and the operation of the energy storage converters is controlled based on the low-load energy storage converters.

5. The safety control method for an energy storage system based on a residual current circuit breaker according to claim 4, characterized in that, Controlling the operation of the energy storage converter based on the low-load energy storage converter includes: A power increase command is sent to the low-load energy storage converter. If the adjusted output power value of the low-load energy storage converter, collected based on the operating status information after the first power increase command, is not close to the first average output power value, a second power increase command is sent based on the low-load energy storage converter to obtain the second increase parameters. Based on the second increase parameters, the low-load energy storage converter is controlled to continue to increase its output power. The second average output power value is calculated based on the balanced adjustment output power values ​​of all energy storage converters collected from the operating status information after the continued increase in output power. Determine whether the deviation between the output power of each energy storage converter and the second average output power value is within the allowable range; if it is within the allowable range, send an equalization maintenance command to all energy storage converters, and control all energy storage converters to maintain the current output power based on the equalization maintenance command.

6. The safety control method for an energy storage system based on a residual current circuit breaker according to any one of claims 1 to 5, characterized in that, The method further includes: If it is determined based on the first communication status information that the mains power has been restored, then the energy storage converter is controlled to stop operating, and a mode switching command is sent to the energy storage converter based on the status information of the energy storage converter stopping operation, so as to switch the operating mode of the energy storage converter from the off-grid operating mode to the grid-connected operating mode, and obtain the grid-connected operating mode status information of the energy storage converter. Based on the grid-connected operation mode status information, a control command is sent to the grid-connected circuit breaker to set the first digital output port of the energy management system to 0 and the second digital output port to 1, thereby obtaining a closing command, and controlling the grid-connected circuit breaker to perform a closing operation based on the closing command. Based on the normal communication status information of the grid-connected circuit breaker, the status information of the grid-connected circuit breaker being in closed operation, the status information of the first digital output port outputting 0 and the second digital output port outputting 1, and the grid-connected operation mode status information of the energy storage converter, a start command is sent to the energy storage converter, and the energy storage converter is controlled to start operation based on the start command.

7. A safety control device for an energy storage system based on a residual current circuit breaker, characterized in that, The energy storage system safety control method based on a residual current circuit breaker as described in any one of claims 1 to 5, wherein the energy storage system safety control device based on a residual current circuit breaker comprises: The tripping control module is used to send a control command to the grid-connected circuit breaker if it is determined that a power outage has occurred based on the first communication status information of the grid-connected circuit breaker monitored by the energy management system. The command sets the first digital output port of the energy management system to 1 and the second digital output port to 0 to obtain a tripping command, and controls the grid-connected circuit breaker to perform a tripping operation based on the tripping command. The first energy storage control module is used to send a shutdown command to the energy storage converter based on the action signal of the grid-connected circuit breaker performing a tripping operation, and to control the energy storage converter to stop operating based on the shutdown command; The mode switching module is used to send a mode switching command to the energy storage converter based on the status information of the energy storage converter stopping operation, so as to switch the operation mode of the energy storage converter from the grid-connected operation mode to the off-grid operation mode, and obtain the off-grid operation mode status information of the energy storage converter. The second energy storage control module is used to send a start command to the energy storage converter based on the status information of the grid-connected circuit breaker communication interruption, the status information of the first digital output port outputting 1 and the second digital output port outputting 0, and the status information of the off-grid operation mode, so as to control the energy storage converter to start and operate based on the start command.

8. A non-transitory computer-readable storage medium, characterized in that, The storage medium stores a computer software program, which, when executed by a processor, implements the energy storage system safety control method based on a residual current circuit breaker as described in any one of claims 1 to 5.

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