Control method and device of energy storage system, electronic equipment and storage medium

Abstract

According to the control method and device of the energy storage system, the electronic equipment and the storage medium provided by the invention, when the energy storage system is switched from the grid-connected state to the off-grid state, the energy storage system is controlled to output the preset duration according to the preset electric power parameter, the deviation between the preset power parameter and the power parameter of the power grid before off-grid is smaller than a preset threshold value; and when the preset duration is reached, controlling the preset electric power parameter output by the energy storage system to be reduced to a preset range corresponding to a rated output electric power parameter of the energy storage system based on a preset electric power parameter change rate, so that the electric power parameter output by the energy storage system can be slowly reduced, and the electric power parameter change is prevented from being too fast. Therefore, the use experience of the user is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of energy storage systems, and in particular, relates to a control method, device, electronic device and storage medium for an energy storage system. Background Art

[0002] In an energy storage system that supports off-grid operation, when the grid voltage is abnormal, the energy storage system will directly switch to off-grid operation. The operating voltage of the energy storage system when off-grid will operate at the rated voltage to ensure that the load connected to the energy storage system can work normally. However, in user or industrial and commercial scenarios, there are many types of loads, and some loads are more sensitive to sudden changes in voltage and frequency, such as lamps and motors. When the voltage changes by more than 20Vac instantly, the intensity of the light can be clearly felt, and the motor will experience obvious jamming, which gives the user a very poor experience. Summary of the invention

[0003] The embodiments of the present application provide a control method, device, electronic device and storage medium for an energy storage system, which can slowly reduce the power parameters output by the energy storage system, avoid excessively rapid changes in the power parameters, and cause abnormal loads, thereby improving the user experience.

[0004] In a first aspect, an embodiment of the present application provides a control method for an energy storage system, when the energy storage system is switched from a grid-connected state to an off-grid state, the energy storage system is controlled to output a preset power parameter for a preset time, wherein the deviation between the preset power parameter and the power parameter of the grid before off-grid is less than a preset threshold;

[0005] When the preset time is reached, the preset power parameter output by the energy storage system is controlled to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on the first preset power parameter change rate.

[0006] In some embodiments, controlling the preset power parameter output by the energy storage system to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on the first preset power parameter change rate includes:

[0007] In the process of controlling the energy storage system to reduce the output power parameter at a first preset power parameter change rate, obtaining the output current of the energy storage system in real time;

[0008] Determine, based on the time sliding window, a current change rate of an output current at a first moment relative to an output current at a second moment, wherein the first moment is an end point of the time sliding window and the second moment is a starting point of the time sliding window;

[0009] When the current change rate corresponding to the first target time sliding window is greater than or equal to a preset change rate threshold, maintaining the power parameter of the energy storage system outputting the first moment corresponding to the first target time sliding window;

[0010] In the process of maintaining the power parameters of the energy storage system outputting the first target time sliding window at the first moment, determining whether the current change rate corresponding to a preset time sliding window after the first target time sliding window is less than or equal to the preset change rate threshold;

[0011] When the current change rate corresponding to the preset time sliding windows is less than or equal to the preset change rate threshold after determining the first target time sliding window, the power parameter output by the energy storage system continues to be reduced based on the first preset power parameter change rate.

[0012] In some embodiments, the method further comprises:

[0013] When the current change rates corresponding to the preset time sliding windows after determining the first target time sliding window are all greater than the preset change rate threshold, reducing the first preset power parameter change rate;

[0014] The power parameter output by the energy storage system continues to be reduced based on the reduced first preset power parameter change rate.

[0015] In some embodiments, the method further comprises:

[0016] Acquiring first detection information of the power grid;

[0017] Determining whether a first preset condition for switching the energy storage system from a grid-connected state to an off-grid state is met based on the first detection information;

[0018] When it is determined based on the first detection information that the first preset condition is satisfied, the energy storage system is controlled to switch from a grid-connected state to an off-grid state.

[0019] In some embodiments, the method further comprises:

[0020] Determine whether the power grid has a fault based on the first detection information;

[0021] In the case that there is no fault in the power grid, determining the power parameters of the power grid before leaving the grid as the power parameters of the power grid at the switching time;

[0022] In the case that there is a fault in the power grid, the power parameters of the power grid before being off-grid are determined to be the power parameters of the power grid before the fault.

[0023] In some embodiments, the method further comprises:

[0024] Acquiring second detection information of the power grid;

[0025] Determine whether a second preset condition for switching from an off-grid state to a grid-connected state is satisfied based on the second detection information;

[0026] When it is determined based on the second detection information that the second preset condition is met, controlling the power parameter output by the energy storage system to increase to the current power parameter of the power grid based on a second preset power parameter change rate;

[0027] When the deviation between the power parameter output by the energy storage system and the current power parameter of the power grid is less than a deviation threshold, the energy storage system is controlled to switch from an off-grid state to a grid-connected state.

[0028] In some embodiments, controlling the power parameter output by the energy storage system to increase to the current power parameter of the power grid based on the second preset power parameter change rate includes:

[0029] In the process of controlling the energy storage system to increase the output power parameter at a second preset power parameter change rate, obtaining the output current of the energy storage system in real time;

[0030] Determine, based on a time sliding window, a current change rate of an output current at a first moment relative to an output current at a second moment, wherein the first moment is an end point of a time sliding window and the second moment is a starting point of the time sliding window;

[0031] When the current change rate corresponding to the second target time sliding window is greater than or equal to a preset change rate threshold, maintaining the power parameter of the energy storage system outputting the first moment corresponding to the second target time sliding window;

[0032] In the process of maintaining the power parameters of the energy storage system outputting the first moment corresponding to the second target time sliding window, determining whether the current change rate corresponding to a preset time sliding window after the second target time sliding window is less than or equal to the preset change rate threshold;

[0033] When the current change rate corresponding to the preset time sliding windows is less than or equal to the preset change rate threshold after determining the second target time sliding window, the power parameter output by the energy storage system continues to be increased based on the second preset power parameter change rate.

[0034] In some embodiments, the method further comprises:

[0035] When the current change rates corresponding to the preset time sliding windows after determining the second target time sliding window are all greater than the preset change rate threshold, reducing the second preset power parameter change rate;

[0036] The power parameter output by the energy storage system continues to increase based on the reduced second preset power parameter change rate.

[0037] In a second aspect, an embodiment of the present application provides a control device for an energy storage system, comprising:

[0038] A first control module, configured to control the energy storage system to output a preset power parameter for a preset duration when the energy storage system is switched from a grid-connected state to an off-grid state, wherein a deviation between the preset power parameter and a power parameter of the grid before off-grid operation is less than a preset threshold;

[0039] The second control module is used to control the preset power parameter output by the energy storage system to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on the first preset power parameter change rate when the preset time is reached.

[0040] In a third aspect, an embodiment of the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method provided in the first aspect when executing the computer program.

[0041] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method provided in the first aspect is implemented.

[0042] Fifthly, an embodiment of the present application provides a computer program product, the computer program product comprising a computer program, and when the computer program is executed by a processor, it is used to implement at least any method as described in the first aspect.

[0043] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0044] The control method of the energy storage system provided in the embodiment of the present application controls the energy storage system to output a preset power parameter for a preset time when the energy storage system switches from a grid-connected state to an off-grid state, wherein the deviation between the preset power parameter and the power parameter of the power grid before going off-grid is less than a preset threshold value; when the preset time is reached, the preset power parameter output by the energy storage system is controlled to be reduced to within a preset range corresponding to the rated output power parameter of the energy storage system based on a first preset power parameter change rate, so that the power parameter output by the energy storage system can be slowly reduced, thereby avoiding excessive changes in the power parameter, which may cause abnormal loads, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0046] Figure 1 A schematic diagram of a control method for an energy storage system provided by the present application;

[0047] Figure 2 A voltage schematic diagram of a control method for an energy storage system provided in an embodiment of the present application during a control process;

[0048] Figure 3 A schematic diagram of an implementation flow of a control method for an energy storage system provided in an embodiment of the present application;

[0049] Figure 4 A schematic diagram of the implementation flow of the control method of the energy storage system provided in the embodiment of the present application;

[0050] Figure 5 A schematic diagram of the implementation flow of the control method of the energy storage system provided in the embodiment of the present application;

[0051] Figure 6 A schematic diagram of the structure of a control device for an energy storage system provided in an embodiment of the present application;

[0052] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0054] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0055] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0056] As used in the specification of this application and the appended claims, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting" depending on the context. Similarly, the phrases "if it is determined" or "if it is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce detected" or "in response to detecting" depending on the context.

[0057] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0058] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0059] Based on the technical problems of the related art, the embodiment of the present application provides a control method of an energy storage system that can be applied to electronic devices. The electronic devices may include: mobile phones, tablet computers, wearable devices, augmented reality (AR) / virtual reality (VR) devices, laptop computers, ultra-mobile personal computers (UMPC), netbooks, personal digital assistants (PDA), and the embodiment of the present application does not impose any restrictions on the specific types of electronic devices. The electronic device may be a controller of the energy storage system.

[0060] The present application provides a control method for an energy storage system. Figure 1 The present application provides a flow chart of a control method for an energy storage system, such as Figure 1 As shown, the method includes:

[0061] Step S101, when the energy storage system switches from a grid-connected state to an off-grid state, the energy storage system is controlled to output a preset power parameter for a preset time, wherein the deviation between the preset power parameter and the power parameter of the grid before off-grid is less than a preset threshold.

[0062] In the embodiments of the present application, the energy storage system refers to a device or system that can store electrical energy and release it when needed. The energy storage system includes a battery energy storage system, a photovoltaic energy storage system, etc. The grid-connected state refers to the state in which the energy storage system is connected to the power grid and can provide electrical energy to the power grid or receive electrical energy from the power grid. The off-grid state refers to the state in which the energy storage system is disconnected from the power grid and operates independently. In the off-grid state, the energy storage system needs to independently assume the power supply task to ensure the stability and continuity of the system.

[0063] In the embodiment of the present application, the preset power parameter refers to the power parameter value set according to the power grid state and the characteristics of the energy storage system before the energy storage system switches state. These parameters usually include one or more of voltage, frequency, phase, etc. The preset duration refers to the length of time that the energy storage system outputs electric energy with the preset power parameter after switching the state. This duration is usually determined according to the characteristics of the energy storage system and the power grid state.

[0064] In the embodiment of the present application, the electronic device can detect the detection information of the power grid and determine whether to switch from the grid-connected state to the off-grid state through the detection information. If it is necessary to switch from the grid-connected state to the off-grid state, the energy storage system can be switched from the grid-connected state to the off-grid state by controlling the off-grid device. The detection information may include: voltage, current, frequency, etc. Taking voltage as an example, if the voltage is abnormal, the grid-connected state is switched to the off-grid state. The voltage abnormality may include: grid power outage, grid undervoltage, grid overvoltage, etc.

[0065] In some embodiments, control information may be received to determine that a switch from a grid-connected state to an off-grid state is required, and then a grid-connected / off-grid device may be controlled to work, thereby switching from a grid-connected state to an off-grid state.

[0066] In the embodiment of the present application, the power parameters of the power grid before going off the grid may be the power parameters of the power grid during normal operation. The deviation between the preset power parameters and the power parameters of the power grid before going off the grid is less than the preset threshold, that is, the deviation between the preset power parameters and the power parameters of the power grid before going off the grid is small, and the deviation threshold can be configured. For example, the preset threshold of voltage may be -1Vac, and the preset threshold of frequency may be -0.1Hz.

[0067] For example, taking the power parameter as voltage, Figure 2 A voltage schematic diagram of a control method for an energy storage system provided in an embodiment of the present application during a control process, such as Figure 2As shown in the figure, before the grid-connected state switches to the off-grid state, the grid voltage is high. Assume that the grid voltage u1 = 1.15Un, where Un is the rated output voltage of the energy storage system. At time T1, the grid is out of power, and the energy storage system switches from the grid-connected state to the off-grid state. At this time, the energy storage system outputs the voltage of the grid before the off-grid state for a preset time.

[0068] In the embodiment of the present application, when the energy storage system needs to switch from the grid-connected state to the off-grid state, the preset duration is first output with the preset power parameters. The deviation between the preset power parameters and the power parameters of the grid before the off-grid state is less than the preset threshold value, ensuring the power stability during the switching process. Avoiding the power parameters from changing too fast, causing abnormal loads, can prevent users from clearly feeling the changes in light intensity and the motor from having obvious jams.

[0069] Step S102, when the preset time is reached, controlling the preset power parameter output by the energy storage system to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on a first preset power parameter change rate.

[0070] In the embodiments of the present application, the rated output power parameter refers to the power parameter value that the energy storage system can continuously and stably output under normal working conditions. These parameters usually include rated voltage, rated current, rated frequency, etc. The preset range refers to the range within which the output power parameter of the energy storage system is allowed to fluctuate.

[0071] In the embodiment of the present application, when the preset time is reached, the power parameters output by the energy storage system are gradually reduced according to the first preset power parameter change rate. By gradually reducing the power parameters, the output power parameters of the energy storage system are finally adjusted to the preset range corresponding to the rated output power parameters. This range ensures that the energy storage system can operate stably and safely. The preset power parameter change rate can be set. Taking voltage as an example, the voltage can be slowly reduced at k0=0.5%Un.

[0072] In the embodiment of the present application, by slowly reducing the power parameters, it is also possible to avoid the power parameters changing too quickly, causing abnormal loads.

[0073] The method provided in the embodiment of the present application controls the energy storage system to output a preset power parameter for a preset time when the energy storage system switches from a grid-connected state to an off-grid state, wherein the deviation between the preset power parameter and the power parameter of the power grid before going off-grid is less than a preset threshold value; when the preset time is reached, the preset power parameter output by the energy storage system is controlled to be reduced to within a preset range corresponding to the rated output power parameter of the energy storage system based on a first preset power parameter change rate, so that the power parameter output by the energy storage system can be slowly reduced, thereby avoiding excessive changes in the power parameter, which may cause load abnormalities, thereby improving the user experience.

[0074] In some embodiments, step S102 may be implemented by the following steps:

[0075] Step S1021, in the process of controlling the energy storage system to reduce the output power parameter at a first preset power parameter change rate, the output current of the energy storage system is obtained in real time.

[0076] In the embodiment of the present application, the output current is the current provided by the energy storage system to the load. During the control process, this value is obtained in real time to monitor the operating status of the energy storage system and make adjustments as needed.

[0077] Step S1022, determining the current change rate of the output current at the first moment relative to the output current at the second moment based on the time sliding window, wherein the first moment is the end point of the time sliding window and the second moment is the starting point of the time sliding window.

[0078] In the embodiment of the present application, the time sliding window is a time range used to calculate and analyze the dynamic changes of data. Within the time sliding window, the current change rate at different times can be calculated. The size of the time sliding window (i.e., the time length) can be adjusted as needed.

[0079] In an embodiment of the present application, within a time window, the current change rate of the output current can be obtained by dividing the difference between the output current at a first moment and the output current at a second moment (usually the starting point of the time window) by the length of the time window.

[0080] Step S1023: When the current change rate corresponding to the first target time sliding window is greater than or equal to a preset change rate threshold, the energy storage system is maintained to output the power parameters of the first moment corresponding to the first target time sliding window.

[0081] In the embodiment of the present application, the preset change rate threshold can be configured, and illustratively, can be configured to 5%.

[0082] In an embodiment of the present application, the first target time sliding window can be a time sliding window used for analysis, which is used to calculate the current change rate and decide whether to maintain the current power parameters based on the change rate. The calculated current change rate can be compared with a preset change rate threshold. If the current change rate is greater than or equal to the threshold, it means that the current power parameters are adjusted too fast or the system state is unstable, and the current power parameters need to be maintained unchanged. The unstable system state can increase or reduce the load on the energy storage system.

[0083] Step S1024, while maintaining the power parameters of the energy storage system outputting the first target time window corresponding to the first moment, determining whether the current change rate corresponding to a preset time window after the first target time window is less than or equal to the preset change rate threshold.

[0084] In the embodiment of the present application, in the process of maintaining the current power parameters, in order to confirm whether the current change rate is stable, multiple time sliding windows (preset) are continuously analyzed. These time sliding windows are used to monitor whether the current change rate has dropped below the preset change rate threshold.

[0085] Step S1025, when it is determined that the current change rate corresponding to the preset time sliding window after the first target time sliding window is less than or equal to the preset change rate threshold, continue to reduce the power parameter output by the energy storage system based on the first preset power parameter change rate.

[0086] In the embodiment of the present application, for each time window within the preset time windows, the current change rate is calculated, and it is determined whether it is less than or equal to the preset change rate threshold. If the current change rates of the preset time windows are all less than or equal to the threshold, it means that the system state has stabilized, and the power parameters can continue to be reduced according to the preset power parameter change rate. After confirming that the system state is stable, the output power parameters of the energy storage system are gradually reduced according to the preset power parameter change rate until the target value is reached or a new control instruction appears.

[0087] In some embodiments, after step S1024, the method further includes:

[0088] Step S1026: when it is determined that the current change rates corresponding to the preset time sliding windows after the first target time sliding window are all greater than the preset change rate threshold, reduce the first preset power parameter change rate.

[0089] In the embodiment of the present application, if the current change rates corresponding to the preset time sliding windows are all greater than the preset change rate threshold after determining the first target time sliding window, it means that the system cannot stably reduce the power parameter at the current preset power parameter change rate. Therefore, it is necessary to reduce the first preset power parameter change rate at this time.

[0090] Step S1027: Continue to reduce the power parameter output by the energy storage system based on the reduced first preset power parameter change rate.

[0091] In the embodiment of the present application, reducing the rate of change can slow down the adjustment speed of the power parameters, allowing the system more time to adapt and adjust, thereby increasing the stability of the system. Using the reduced preset power parameter change rate, continue to control the energy storage system to reduce the output power parameters. In this process, it is still necessary to obtain the output current in real time and use the time sliding window technology to monitor the current change rate to ensure that the system can stably reduce the power parameters at the new change rate.

[0092] Following the above example, see Figure 2At T2, the output voltage of the energy storage system slowly decreases, and the output voltage is: u(t) = u1-kt, where u1 = 1.15Un, k is the first preset power parameter change rate, which can be set according to actual conditions, such as the initial k0 = 0.5% Un. Under the k0 parameter, the output current of the PCS is monitored in real time. If the current I(1) at the current moment is less than or equal to 5% of the output current I(0) at the previous moment, k0 is kept unchanged and the output voltage is gradually changed. If the current I(1) at the current moment is greater than the output current I(0) at the previous moment by more than 5%, the output voltage U is kept unchanged, and the sizes of I(1) and I(0) are continuously observed. If it is less than 5%, the output voltage is continued to change with k0; if it is still greater than 5%, the size of K is adjusted, and then the output voltage is continued to change. By continuously adjusting the k value, the current change is ≤5%. At T3, the output voltage of the energy storage system is reduced to Un and remains unchanged.

[0093] The method provided in the embodiment of the present application can make the system more flexible and robust in the face of unstable factors by dynamically adjusting the preset power parameter change rate. Excessive power parameter change rate may cause impact or damage to the hardware of the energy storage system. By reducing the change rate, the system hardware can be protected from damage. Under the premise of ensuring system stability, gradually reducing the power parameters can make a smoother transition to the target power output state, thereby improving the quality and efficiency of power output.

[0094] In some embodiments, before step S101, the method further includes:

[0095] Step S1011, obtaining first detection information of the power grid.

[0096] In an embodiment of the present application, the detection information may include: key parameters such as voltage, current, frequency, phase, and power grid fault signals or warning information. The key parameters such as voltage, current, frequency, phase, and possible power grid fault signals or warning information can be obtained in real time through sensors, measuring devices or communication interfaces installed on the power grid or energy storage system side.

[0097] Step S1012: determining, based on the first detection information, whether a first preset condition for switching the energy storage system from a grid-connected state to an off-grid state is satisfied.

[0098] In the embodiment of the present application, the first preset condition is formulated according to the operation requirements, safety specifications and strategies of the power grid and the energy storage system. It may include the power grid voltage exceeding the normal range, the power grid frequency being unstable, the power grid fault signal being issued, the internal fault of the energy storage system or the maintenance requirement, etc.

[0099] In an embodiment of the present application, by analyzing the first detection information, it is determined whether the power grid is in an unstable state or there is a situation that poses a threat to the energy storage system, and whether the energy storage system meets the technical and safety requirements for switching to an off-grid state.

[0100] Step S1013: When it is determined based on the first detection information that the first preset condition is satisfied, controlling the energy storage system to switch from a grid-connected state to an off-grid state.

[0101] In the embodiment of the present application, after confirming that the first preset condition is met, the switching control logic of the energy storage system is started, and the connection switch between the energy storage system and the power grid can be disconnected, so that the energy storage system can be switched from a grid-connected state to an off-grid state.

[0102] In the embodiments of the present application, by real-time monitoring of the grid status and rapid response, the energy storage system can be switched to an off-grid state in a timely manner when the grid fails or becomes unstable, thereby protecting the energy storage system and critical loads from damage.

[0103] In some embodiments, after step S1011, the method further includes:

[0104] Step S1014: determine whether there is a fault in the power grid based on the first detection information.

[0105] In the embodiment of the present application, the fault may be overvoltage, undervoltage, power failure, short circuit, etc.

[0106] Step S1015, when there is no fault in the power grid, determining the power parameters of the power grid before going off-grid as the power parameters of the power grid at the switching moment.

[0107] In the embodiment of the present application, if there is no fault in the power grid, if the power grid is in a normal state and no fault signal is detected, then the switching of the energy storage system may be due to maintenance, testing or other non-fault reasons. In this case, the power parameters of the power grid before going off-grid should be determined as the power parameters of the power grid at the switching time (i.e., the time when the energy storage system starts to switch from on-grid to off-grid).

[0108] Step S1016, when there is a fault in the power grid, determine the power parameters of the power grid before going off-grid as the power parameters of the power grid before the fault.

[0109] In the embodiment of the present application, if a fault is detected in the power grid, the switching of the energy storage system is to protect the system and critical loads from the fault. In this case, the power parameters of the power grid before leaving the grid should be determined as the power parameters of the power grid before the fault occurs. These parameters are the operating parameters of the power grid in a normal state, and will serve as the basis for the energy storage system to simulate the operation of the power grid in an off-grid state to ensure that the critical loads can obtain a stable and compliant power supply.

[0110] The method provided in the embodiment of the present application can ensure that the energy storage system can continue to provide stable and reliable power supply to critical loads in the off-grid state by accurately judging the state of the grid and determining the power parameters before going off-grid. When the grid fails, it switches to the off-grid state in time and operates based on the power parameters before the failure, which can protect the energy storage system and critical loads from the impact of the grid failure.

[0111] In some embodiments, after step S102, Figure 3 A schematic diagram of an implementation flow of a control method for an energy storage system provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the method also includes:

[0112] Step S103, obtaining second detection information of the power grid.

[0113] In the embodiment of the present application, the second detection information may be: key parameters such as voltage, current, frequency, and phase of the power grid.

[0114] In the embodiment of the present application, when the energy storage system is off-grid, the state of the power grid needs to be continuously monitored, which can be achieved by installing sensors, measuring equipment or communication interfaces on the power grid side, and obtaining key parameters such as voltage, current, frequency, and phase of the power grid in real time. The second detection information should be comprehensive and accurate to reflect the current state of the power grid and whether it is suitable for the energy storage system to be connected to the grid.

[0115] Step S104: determining whether a second preset condition for switching from an off-grid state to a grid-connected state is satisfied based on the second detection information.

[0116] In the embodiment of the present application, the second preset condition is formulated according to the operation requirements, safety specifications and strategies of the power grid and the energy storage system. It may include that the voltage and frequency of the power grid are within the normal range, the phase matches the energy storage system, and there is no fault signal in the power grid. By analyzing the second detection information, it is determined whether the power grid is in a stable state and whether the energy storage system meets the technical and safety requirements for grid connection.

[0117] Step S105 , when it is determined based on the second detection information that the second preset condition is met, control the power parameter output by the energy storage system to increase to the current power parameter of the power grid based on a second preset power parameter change rate.

[0118] In the embodiment of the present application, after confirming that the second preset condition for grid connection is met, it is necessary to gradually adjust the output power parameters of the energy storage system to match the current power parameters of the power grid. This can be achieved by a preset power parameter change rate, that is, gradually increasing the output voltage and frequency of the energy storage system at a certain rate to avoid sudden impact on the power grid. The second preset power parameter change rate should be set according to the actual situation of the power grid and the energy storage system to ensure a smooth transition.

[0119] Step S106, when the deviation between the power parameter output by the energy storage system and the current power parameter of the power grid is less than a deviation threshold, controlling the energy storage system to switch from an off-grid state to a grid-connected state.

[0120] In the embodiment of the present application, the deviation threshold can be configured. In the process of adjusting the output power parameters of the energy storage system, it is necessary to monitor the deviation between the output of the energy storage system and the current power parameters of the power grid in real time. The deviation may include voltage deviation, phase deviation, frequency deviation, etc. These deviations should be kept within a certain threshold range to ensure the synchronization and stability between the energy storage system and the power grid.

[0121] In the embodiment of the present application, when the deviation between the output of the energy storage system and the current power parameters of the power grid is less than the preset deviation threshold, it means that the energy storage system has achieved a good match with the power grid. At this time, the grid-connected control logic of the energy storage system can be started, such as closing the grid-connected switch, adjusting the control strategy and parameters, etc., to switch the energy storage system from an off-grid state to a grid-connected state.

[0122] The method provided in the embodiment of the present application can ensure a smooth transition between the energy storage system and the power grid by accurately controlling the grid connection process of the energy storage system, avoid impact on the power grid and other equipment, and improve the overall reliability of the system. The energy storage system can be flexibly switched between grid connection and off-grid status, and can meet the operating requirements in different scenarios, such as grid fault recovery and energy storage system maintenance.

[0123] By accurately matching the output of the energy storage system with the current power parameters of the power grid, it can be ensured that the energy storage system can efficiently participate in grid scheduling and balancing when connected to the grid, thereby improving energy utilization efficiency.

[0124] In some embodiments, step S105 may be implemented by the following steps:

[0125] Step S1051, in the process of controlling the energy storage system to increase the output power parameter at a second preset power parameter change rate, the output current of the energy storage system is obtained in real time.

[0126] In the embodiment of the present application, the output current of the energy storage system can be obtained in real time by means of a current sensor or a measuring device installed at the output end of the energy storage system.

[0127] Step S1052, determining the current change rate of the output current at a first moment relative to the output current at a second moment based on a time sliding window, wherein the first moment is an end point of a time sliding window and the second moment is a starting point of the time sliding window.

[0128] In an embodiment of the present application, a time sliding window technique is used to evaluate the rate of change of the output current of the energy storage system. The time sliding window is a fixed time interval used to compare the current values ​​at different times. In each time sliding window, the current change rate of the output current at the first moment (the end point of the time sliding window) relative to the output current at the second moment (the starting point of the time sliding window) is determined. The current change rate can be obtained by calculating the difference between the current values ​​at the two moments and then dividing it by the duration of the time sliding window.

[0129] Step S1053: When the current change rate corresponding to the second target time sliding window is greater than or equal to a preset change rate threshold, the energy storage system is maintained to output the power parameters of the first moment corresponding to the second target time sliding window.

[0130] In the embodiment of the present application, for each time window, the current change rate corresponding to it is compared with the preset change rate threshold. If the current change rate corresponding to the second target time window (i.e., the time window currently concerned) is greater than or equal to the preset change rate threshold, it means that the current output of the energy storage system changes too fast, and the current power parameters need to be maintained to avoid impacting the power grid.

[0131] Step S1054, while maintaining the power parameters of the energy storage system outputting the first moment corresponding to the second target time sliding window, determine whether the current change rate corresponding to a preset time sliding window after the second target time sliding window is less than or equal to the preset change rate threshold.

[0132] In the embodiment of the present application, in the process of maintaining the current power parameters, the time sliding window technology is continued to monitor the current change rate. It is determined whether the current change rates corresponding to the preset continuous time sliding windows after the second target time sliding window are all less than or equal to the preset change rate threshold. The determination of whether the current change rates corresponding to the preset continuous time sliding windows after the second target time sliding window are all less than or equal to the preset change rate threshold is to confirm whether the current output by the energy storage system has stabilized and is ready to continue to increase the power parameters at a safe rate.

[0133] Step S1055, when it is determined that the current change rate corresponding to the preset time sliding window after the second target time sliding window is less than or equal to the preset change rate threshold, continue to increase the power parameter output by the energy storage system based on the second preset power parameter change rate.

[0134] In the embodiment of the present application, if the current change rates corresponding to the preset time sliding windows after the second target time sliding window are all less than or equal to the preset change rate threshold, it means that the current output by the energy storage system has stabilized and the power parameters can be safely increased. At this time, based on the second preset power parameter change rate, the power parameters output by the energy storage system are gradually restored and continued to increase until they reach a level that matches the current power parameters of the power grid.

[0135] In some embodiments, after step S1054, the method further includes:

[0136] Step S1056: when it is determined that the current change rates corresponding to the preset time sliding windows after the second target time sliding window are all greater than the preset change rate threshold, reduce the second preset power parameter change rate.

[0137] In the embodiment of the present application, if the current change rates within these time sliding windows are all greater than the preset change rate threshold, it means that the adjustment speed of the energy storage system output may be too fast. Therefore, it is necessary to reduce the second preset power parameter change rate.

[0138] Step S1057: Continue to increase the power parameter output by the energy storage system based on the reduced second preset power parameter change rate.

[0139] In the embodiment of the present application, after adjusting the power parameter change rate, the power parameter output by the energy storage system continues to be increased based on the new, smaller power parameter change rate. This process requires continuous monitoring of the current change rate to ensure that the power parameter output by the energy storage system can be increased in a more stable and safe manner. After adjusting the power parameter change rate and continuing to increase the output, the current change rate needs to be re-evaluated to determine whether the new power parameter change rate meets the requirements. If the current change rate is still too large, it may be necessary to further adjust the power parameter change rate,

[0140] Following the above example, see Figure 2 At time T4, the grid receives power, and the energy storage system detects the grid power. The output voltage of the energy storage system rises slowly, and the output voltage is: u(t) = Un + gt, where u1 = 1.15Un, and g is the second preset power parameter change rate, which can be set according to actual conditions, such as g = 0.5% Un. The same algorithm as the variable constant k is used to adjust the size of g so that during the voltage adjustment process, the output current of the PCS changes less than or equal to 5% relative to the previous moment. At time T5, the output voltage of the energy storage system is consistent with the grid voltage at this moment, and the system is disconnected from the grid and connected to the grid.

[0141] In the embodiment of the present application, the voltage in the above example can be changed into frequency, thereby achieving frequency adjustment.

[0142] In the embodiment of the present application, during the process of adjusting the power parameters, if the voltage is not satisfied, the voltage is adjusted; if the frequency is not satisfied, the frequency is adjusted; if both are not satisfied, the adjustments are performed simultaneously.

[0143] The method provided in the embodiment of the present application can ensure that the power parameters output by the energy storage system will not change suddenly by dynamically adjusting the power parameter change rate, thereby avoiding damage to the power grid and the energy storage system equipment. By accurately controlling the increase process of the power parameters output by the energy storage system, it is possible to ensure the smooth connection between the energy storage system and the power grid, improve energy utilization efficiency, and reduce potential risks in the connection process.

[0144] Based on the above embodiments, the present application provides a control method for an energy storage system. Figure 4 A schematic diagram of the implementation flow of the control method of the energy storage system provided in the embodiment of the present application is shown in FIG. Figure 4 As shown, including:

[0145] Step S401, start grid-connected operation.

[0146] Step S402: Check whether the grid voltage and frequency are within the normal range.

[0147] In the embodiment of the present application, if no, execute step S403, and if yes, execute step S404.

[0148] Step S403, switching to off-grid, output voltage u1, frequency f1.

[0149] In the embodiment of the present application, after step S303, step S305 is executed.

[0150] Step S405, slowly adjusting the output voltage and frequency to the rated values.

[0151] After step S305, the off-grid process ends.

[0152] Step S404, recording the current voltage u1 and frequency value f1.

[0153] In the embodiment of the present application, after step S304, step S302 is continued to be executed.

[0154] Based on the above embodiments, the present application provides a control method for an energy storage system. Figure 5 A schematic diagram of the implementation flow of the control method of the energy storage system provided in the embodiment of the present application is shown in FIG. Figure 5 As shown, including:

[0155] Step S501, start off-grid operation.

[0156] Step S502, detecting whether the power grid is normal.

[0157] In the embodiment of the present application, if no, execute step S501, and if yes, execute step S503.

[0158] Step S503, the off-grid operation slowly adjusts the voltage frequency and phase of the off-grid output to be consistent with the grid.

[0159] Step S504, switching from off-grid to grid-connected, and running on-grid.

[0160] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0161] According to the aforementioned embodiments, the embodiments of the present application provide a control device for an energy storage system, wherein the modules included in the device and the units included in the modules can be implemented by a processor in a computer device; of course, they can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU, Central Processing Unit), a microprocessor (MPU, Microprocessor Unit), a digital signal processor (DSP, Digital Signal Processing) or a field programmable gate array (FPGA, Field Programmable Gate Array), etc.

[0162] Figure 6 A schematic diagram of the structure of a control device for an energy storage system provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the control device 600 of the energy storage system includes:

[0163] The first control module 601 is used to control the energy storage system to output a preset power parameter for a preset time when the energy storage system is switched from a grid-connected state to an off-grid state, wherein the deviation between the preset power parameter and the power parameter of the grid before off-grid is less than a preset threshold;

[0164] The second control module 602 is used to control the preset power parameter output by the energy storage system to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on a preset power parameter change rate when the preset time is reached.

[0165] In some embodiments, the second control module includes:

[0166] A first detection unit, used to obtain the output current of the energy storage system in real time during the process of controlling the energy storage system to reduce the output power parameter at a preset power parameter change rate;

[0167] A first determining unit, configured to determine a current change rate of an output current at a first moment relative to an output current at a second moment based on a time sliding window, wherein the first moment is an end point of the time sliding window and the second moment is a starting point of the time sliding window;

[0168] A first maintaining unit, configured to maintain the power parameter of the energy storage system outputting the first target time sliding window at a first moment corresponding to the first target time sliding window when the current change rate corresponding to the first target time sliding window is greater than or equal to a preset change rate threshold;

[0169] A second determination unit is used to determine whether a current change rate corresponding to a preset time sliding window after the first target time sliding window is less than or equal to a preset change rate threshold value in the process of maintaining the power parameter of the energy storage system outputting the first moment corresponding to the first target time sliding window;

[0170] The first reduction unit is used to continue to reduce the power parameter output by the energy storage system based on the first preset power parameter change rate when the current change rate corresponding to the preset time sliding window is less than or equal to the preset change rate threshold after determining the first target time sliding window.

[0171] In some embodiments, the second control module includes:

[0172] a first reducing unit, configured to reduce the first preset power parameter change rate when the current change rates corresponding to the preset time sliding windows are all greater than the preset change rate threshold after determining the first target time sliding window;

[0173] The second reducing unit is used to continue reducing the power parameter output by the energy storage system based on the reduced first preset power parameter change rate.

[0174] In some embodiments, the control device 600 of the energy storage system further includes:

[0175] A first acquisition module, used to acquire first detection information of the power grid;

[0176] A first determination module, configured to determine whether a first preset condition for switching the energy storage system from a grid-connected state to an off-grid state is satisfied based on the first detection information;

[0177] A third control module is configured to control the energy storage system to switch from a grid-connected state to an off-grid state when it is determined based on the first detection information that the first preset condition is satisfied.

[0178] In some embodiments, the control device 600 of the energy storage system further includes:

[0179] A second determination module, configured to determine whether the power grid has a fault based on the first detection information;

[0180] A third determination module is used to determine, when there is no fault in the power grid, that the power parameters of the power grid before leaving the grid are the power parameters of the power grid at the switching time;

[0181] The fourth determination module is used to determine, when there is a fault in the power grid, that the power parameters of the power grid before going off-grid are the power parameters of the power grid before the fault.

[0182] In some embodiments, the control device 600 of the energy storage system further includes:

[0183] A second acquisition module, used to acquire second detection information of the power grid;

[0184] A fifth determination module, configured to determine whether a second preset condition for switching from an off-grid state to a grid-connected state is satisfied based on the second detection information;

[0185] a fourth control module, configured to control the power parameter output by the energy storage system to increase to the current power parameter of the power grid based on a second preset power parameter change rate when it is determined based on the second detection information that the second preset condition is satisfied;

[0186] The fifth control module is used to control the energy storage system to switch from an off-grid state to a grid-connected state when the deviation between the power parameter output by the energy storage system and the current power parameter of the power grid is less than a deviation threshold.

[0187] In some embodiments, the fourth control module includes:

[0188] A second detection unit, used to obtain the output current of the energy storage system in real time during the process of controlling the energy storage system to increase the output power parameter at a second preset power parameter change rate;

[0189] A third determining unit, configured to determine a current change rate of an output current at a first moment relative to an output current at a second moment based on a time sliding window, wherein the first moment is an end point of a time sliding window and the second moment is a starting point of the time sliding window;

[0190] A second maintaining unit, configured to maintain the power parameter of the energy storage system outputting the first moment corresponding to the second target time sliding window when the current change rate corresponding to the second target time sliding window is greater than or equal to a preset change rate threshold;

[0191] a fourth determination unit, configured to determine whether a current change rate corresponding to a preset time sliding window after the second target time sliding window is less than or equal to a preset change rate threshold value in a process of maintaining the power parameter of the energy storage system outputting the first moment corresponding to the second target time sliding window;

[0192] An increasing unit is used to continue to increase the power parameter output by the energy storage system based on the second preset power parameter change rate when the current change rate corresponding to the preset time sliding window is less than or equal to the preset change rate threshold after determining the second target time sliding window.

[0193] In some embodiments, the fourth control module includes:

[0194] a second reducing unit, configured to reduce the second preset power parameter change rate when the current change rates corresponding to the preset time sliding windows are all greater than the preset change rate threshold after determining the second target time sliding window;

[0195] An increasing unit is used to continue to increase the power parameter output by the energy storage system based on the reduced second preset power parameter change rate.

[0196] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0197] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0198] Figure 7 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 7 As shown, the electronic device 3 of this embodiment may include: at least one processor 30 ( Figure 7Only one processor 30 is shown in the figure), a memory 31, and a computer program 32 stored in the memory 31 and executable on at least one processor 30. When the processor 30 executes the computer program 32, the steps in any of the above-mentioned method embodiments are implemented; or, when the processor 30 executes the computer program 32, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0199] Exemplarily, the computer program 32 may be divided into one or more modules / units, one or more modules / units are stored in the memory 31, and are executed by the processor 30 to complete the present application. One or more modules / units may be a series of computer program 32 instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 32 in the electronic device 3.

[0200] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program 32. When the computer program 32 is executed by the processor 30, the steps in the above-mentioned method embodiments can be implemented.

[0201] An embodiment of the present application provides a computer program product. When the computer program product runs on an electronic device, the electronic device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0202] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. According to this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program 32, and the computer program 32 can be stored in a computer-readable storage medium. When the computer program 32 is executed by the processor 30, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program 32 includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying the computer program code to the terminal, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), an electric carrier signal, a telecommunication signal and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0203] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0204] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0205] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0206] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0207] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

[0208] The relevant user personal information that may be involved in the various embodiments of this application is strictly in accordance with the requirements of laws and regulations, following the principles of legality, legitimacy and necessity, based on the reasonable purposes of business scenarios, to process the personal information that users actively provide during the use of products / services or generated due to the use of products / services, as well as the personal information obtained with the user's authorization.

[0209] The user personal information processed by the applicant will vary depending on the specific product / service scenario, and shall be based on the specific scenario in which the user uses the product / service, which may involve the user's account information, device information, driving information, vehicle information or other related information. The applicant will treat the user's personal information and its processing with a high degree of diligence.

[0210] The Applicant attaches great importance to the security of user personal information and has adopted reasonable and feasible security protection measures that comply with industry standards to protect user information and prevent personal information from being accessed, disclosed, used, modified, damaged or lost without authorization.

Claims

1. A control method for an energy storage system, characterized in that: include: When the energy storage system switches from a grid-connected state to an off-grid state, the energy storage system is controlled to output a preset power parameter for a preset time, wherein the deviation between the preset power parameter and the power parameter of the grid before off-grid is less than a preset threshold; When the preset time is reached, the preset power parameter output by the energy storage system is controlled to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on the first preset power parameter change rate.

2. The method according to claim 1, characterized in that The step of controlling the preset power parameter output by the energy storage system to decrease to a preset range corresponding to the rated output power parameter of the energy storage system based on the first preset power parameter change rate includes: In the process of controlling the energy storage system to reduce the output power parameter at a first preset power parameter change rate, obtaining the output current of the energy storage system in real time; Determine, based on the time sliding window, a current change rate of an output current at a first moment relative to an output current at a second moment, wherein the first moment is an end point of the time sliding window and the second moment is a starting point of the time sliding window; When the current change rate corresponding to the first target time sliding window is greater than or equal to a preset change rate threshold, maintaining the power parameter of the energy storage system outputting the first moment corresponding to the first target time sliding window; In the process of maintaining the power parameters of the energy storage system outputting the first target time sliding window at the first moment, determining whether the current change rate corresponding to a preset time sliding window after the first target time sliding window is less than or equal to the preset change rate threshold; When the current change rate corresponding to the preset time sliding windows is less than or equal to the preset change rate threshold after determining the first target time sliding window, the power parameter output by the energy storage system continues to be reduced based on the first preset power parameter change rate.

3. The method according to claim 2, characterized in that The method further comprises: When the current change rates corresponding to the preset time sliding windows after determining the first target time sliding window are all greater than the preset change rate threshold, reducing the first preset power parameter change rate; The power parameter output by the energy storage system continues to be reduced based on the reduced first preset power parameter change rate.

4. The method according to any one of claims 1 to 3, characterized in that: The method further comprises: Acquiring first detection information of the power grid; Determining whether a first preset condition for switching the energy storage system from a grid-connected state to an off-grid state is met based on the first detection information; When it is determined based on the first detection information that the first preset condition is satisfied, the energy storage system is controlled to switch from a grid-connected state to an off-grid state.

5. The method according to claim 4, characterized in that The method further comprises: Determine whether the power grid has a fault based on the first detection information; In the case that there is no fault in the power grid, determining the power parameters of the power grid before leaving the grid as the power parameters of the power grid at the switching time; In the case that there is a fault in the power grid, the power parameters of the power grid before being off-grid are determined to be the power parameters of the power grid before the fault.

6. The method according to claim 1, characterized in that The method further comprises: Acquiring second detection information of the power grid; Determine whether a second preset condition for switching from an off-grid state to a grid-connected state is satisfied based on the second detection information; When it is determined based on the second detection information that the second preset condition is met, controlling the power parameter output by the energy storage system to increase to the current power parameter of the power grid based on a second preset power parameter change rate; When the deviation between the power parameter output by the energy storage system and the current power parameter of the power grid is less than a deviation threshold, the energy storage system is controlled to switch from an off-grid state to a grid-connected state.

7. The method according to claim 6, characterized in that The step of controlling the power parameter output by the energy storage system to increase to the current power parameter of the power grid based on the second preset power parameter change rate includes: In the process of controlling the energy storage system to increase the output power parameter at a second preset power parameter change rate, obtaining the output current of the energy storage system in real time; Determine, based on a time sliding window, a current change rate of an output current at a first moment relative to an output current at a second moment, wherein the first moment is an end point of a time sliding window and the second moment is a starting point of the time sliding window; When the current change rate corresponding to the second target time sliding window is greater than or equal to a preset change rate threshold, maintaining the power parameter of the energy storage system outputting the first moment corresponding to the second target time sliding window; In the process of maintaining the power parameters of the energy storage system outputting the first moment corresponding to the second target time sliding window, determining whether the current change rate corresponding to a preset time sliding window after the second target time sliding window is less than or equal to the preset change rate threshold; When the current change rate corresponding to the preset time sliding windows is less than or equal to the preset change rate threshold after determining the second target time sliding window, the power parameter output by the energy storage system continues to be increased based on the second preset power parameter change rate.

8. The method according to claim 7, characterized in that The method further comprises: When the current change rates corresponding to the preset time sliding windows after determining the second target time sliding window are all greater than the preset change rate threshold, reducing the second preset power parameter change rate; The power parameter output by the energy storage system continues to increase based on the reduced second preset power parameter change rate.

9. A control device for an energy storage system, characterized in that: include: A first control module, configured to control the energy storage system to output a preset power parameter for a preset duration when the energy storage system is switched from a grid-connected state to an off-grid state, wherein a deviation between the preset power parameter and a power parameter of the grid before off-grid operation is less than a preset threshold; The second control module is used to control the preset power parameter output by the energy storage system to decrease to within a preset range corresponding to the rated output power parameter of the energy storage system based on the first preset power parameter change rate when the preset time is reached.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 8 is implemented.

11. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 8 is implemented.

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