Off-grid power control method, device, electronic equipment, storage medium and product of energy storage system

Abstract

The embodiment of the present application discloses an off-grid power control method, device, electronic device, storage medium and product of an energy storage system, which is applied to an EMS in an energy storage system. The energy storage system also includes at least one energy storage device and multiple branch lines. The method includes: when each branch line is disconnected from the power grid, obtaining the line information of the branch line where the energy storage device is located and the device information of the energy storage device, the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device; determining the target discharge power of each energy storage device according to the line information of the branch line where the energy storage device is located and the corresponding device information; controlling the discharge power of at least one energy storage device to be the corresponding target discharge power. By implementing the embodiment of the present application, the energy storage device can operate normally in the branch line of the energy storage system when off-grid, which improves the flexibility of connecting the energy storage device to the branch line of the energy storage system.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage system applications, and in particular to an off-grid power control method, device, electronic equipment, storage medium and product of an energy storage system. Background Art

[0002] At present, the generation of green electricity generally relies on photovoltaic, wind power, hydropower, etc., but wind and solar energy generally have strong intermittent and volatile problems, which will cause instability of the power grid, insufficient electricity during peak hours, too much electricity during valley hours, and unstable voltage will also cause damage to electricity. Therefore, insufficient electricity demand or insufficient grid acceptance capacity may cause the problem of "abandoning wind and solar power". To solve these problems, we must rely on energy storage. That is, converting electrical energy into other forms of energy through physical or chemical means and storing them, and converting energy into electrical energy when needed.

[0003] An energy storage system is a system that can store electrical energy by setting up energy storage devices so that it can be released for use when needed. For example, the energy storage devices can be set in branch lines of the energy storage system.

[0004] However, when the energy storage system operates independently of the public power grid, that is, off-grid, how the energy storage equipment should operate is a problem that needs to be solved urgently. Summary of the invention

[0005] The embodiments of the present application disclose an off-grid power control method, device, electronic device, storage medium and product of an energy storage system, which can calculate the target discharge power of each energy storage device in an off-grid situation, thereby controlling the energy storage device to operate according to the target discharge power.

[0006] In a first aspect, an embodiment of the present application discloses an off-grid power control method for an energy storage system, which is applied to an energy management system in the energy storage system, wherein the energy storage system further comprises at least one energy storage device and a plurality of branch lines, each branch line being respectively connected to a power grid, and the at least one energy storage device being arranged in at least some of the branch lines among the plurality of branch lines, and the method comprising:

[0007] When each branch line is disconnected from the power grid, obtaining line information of the branch line where the at least one energy storage device is located and device information of the at least one energy storage device, wherein the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device;

[0008] Determine the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device;

[0009] The discharge power of the at least one energy storage device is controlled to be the corresponding target discharge power.

[0010] As an optional implementation, in the first aspect of the embodiment of the present application, the current of the branch line includes the maximum allowable discharge current of the branch line, and the determining the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device includes:

[0011] Obtaining a ratio of a rated discharge current of a target energy storage device to a total rated discharge current of all energy storage devices in a target branch line, wherein the target energy storage device is one of the energy storage devices in the energy storage system, and the target branch line is a branch line where the target energy storage device is located;

[0012] Determine the maximum allowable discharge current of the target energy storage device according to the product of the ratio and the maximum allowable discharge current of the target branch line;

[0013] The target discharge power of the target energy storage device is determined according to the maximum allowable discharge current of the target energy storage device and the system voltage of the energy storage system.

[0014] As an optional implementation, in the first aspect of the embodiment of the present application, the current of the branch line also includes an actual discharge current of the branch line, and determining the maximum allowable discharge current of the target energy storage device according to the product of the ratio and the maximum allowable discharge current of the target branch line includes:

[0015] Obtaining a load current of the target branch line according to a difference between a sum of actual discharge currents of all energy storage devices in the target branch line and an actual discharge current of the target branch line;

[0016] The maximum allowable discharge current of the target branch line is obtained according to the sum of the current protection setting value of the target branch line and the load current, and the current protection setting value is a preset current value.

[0017] As an optional implementation manner, in the first aspect of the embodiments of the present application, the method further includes:

[0018] Detecting whether an available quantity of at least one energy storage device in the energy storage system changes;

[0019] When a change in the available quantity is detected, the target discharge power of each energy storage device is re-determined.

[0020] As an optional implementation manner, in the first aspect of the embodiment of the present application, the detecting whether the available quantity of the at least one energy storage device in the energy storage system changes includes:

[0021] In the case where it is detected that at least one of the energy storage devices is in a fault state, determining that the available quantity of the at least one energy storage device changes; or,

[0022] In the case where it is detected that the remaining power of at least one of the energy storage devices is less than a preset first threshold, determining that the available quantity of the at least one energy storage device has changed; or,

[0023] In the case of detecting that a state of the power grid has changed, determining that the available quantity of the at least one energy storage device has changed, wherein the state of the power grid includes the energy storage device being unplugged from the power grid and / or newly inserted into the power grid.

[0024] As an optional implementation, in a first aspect of the embodiment of the present application, the energy storage system further includes an on-grid switch, the on-grid switch is arranged on a bus of the energy storage system, the energy storage system is connected to the power grid via the on-grid switch, and the method further includes:

[0025] determining whether the target indication information indicates that the grid-connected and off-grid switch is in a disconnected state and whether the grid voltage state does not meet a preset condition, wherein the preset condition is that the grid voltage is within a range of a preset second threshold value and a preset third threshold value and the duration is greater than a preset fourth threshold value, and the third threshold value is greater than the second threshold value, and the target indication information is used to indicate the working state of the grid-connected and off-grid switch, and the working state includes the disconnected state or the closed state;

[0026] When the target indication information indicates that the on-grid and off-grid switch is in the disconnected state and the grid voltage state does not satisfy a preset condition, it is determined that each branch line is disconnected from the grid.

[0027] As an optional implementation, in the first aspect of the embodiment of the present application, before determining the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, the method further includes:

[0028] Determining the state of the energy storage device according to the remaining power of the energy storage device, the state of the energy storage device including a discharging state and a standby state;

[0029] Determine whether the energy storage device performs a discharge operation according to a preset energy storage device execution strategy and the state of the energy storage device, wherein the preset energy storage device execution strategy includes determining that the energy storage device performs a discharge operation when the state of the energy storage device is a discharge state.

[0030] A second aspect of an embodiment of the present application discloses an off-grid power control device for an energy storage system, which is applied to an energy management system in the energy storage system, wherein the energy storage system further comprises at least one energy storage device and a plurality of branch lines, each branch line being respectively connected to a power grid, and the at least one energy storage device being arranged in at least some of the branch lines among the plurality of branch lines, and the device comprises:

[0031] An information acquisition module, configured to acquire, when each branch line is disconnected from the power grid, line information of the branch line where the at least one energy storage device is located and device information of the at least one energy storage device, wherein the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device;

[0032] A power determination module, used to determine the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device;

[0033] The control module is used to control the discharge power of the at least one energy storage device to be the corresponding target discharge power.

[0034] A third aspect of an embodiment of the present application discloses an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor implements the method described above.

[0035] A fourth aspect of an embodiment of the present application discloses a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the method described above when executed by a processor.

[0036] A fifth aspect of an embodiment of the present application discloses a computer program product, including a non-transitory computer-readable storage medium storing a computer program, wherein the computer program implements the method described above when executed by a processor.

[0037] Compared with the related art, the embodiments of the present application include at least the following beneficial effects:

[0038] The energy storage system includes an energy management system, at least one energy storage device and a plurality of branch lines, each branch line is connected to the power grid, and at least one energy storage device is arranged in at least part of the branch lines.

[0039] The energy management system in the energy storage system obtains line information of a branch line where at least one energy storage device is located and device information of at least one energy storage device, the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device; according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, the target discharge power of each energy storage device is determined, and the discharge power of at least one energy storage device is controlled to be the corresponding target discharge power.

[0040] In this solution, when off-grid, the target discharge power of each energy storage device is determined and controlled by obtaining the line information and device information of the branch line where each energy storage device is located, so that when the energy storage system is off-grid, the energy storage device can operate normally in the branch line of the energy storage system, and the target discharge power is determined based on the information of the branch line where each energy storage device is located, thereby improving the flexibility of connecting the energy storage device to the branch line of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments 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 work.

[0042] Figure 1 A schematic diagram of the structure of a household energy storage system in one embodiment;

[0043] Figure 2 This is an application scenario diagram of an off-grid power control method for an energy storage system in an embodiment;

[0044] Figure 3 is a flow chart of an off-grid power control method for an energy storage system in one embodiment;

[0045] Figure 4 is a flow chart of a method for determining a target discharge power of a target energy storage device in one embodiment;

[0046] Figure 5 A schematic diagram of the overall process of an off-grid power control method for an energy storage system in one embodiment;

[0047] Figure 6 A block diagram of an off-grid power control device for an energy storage system in one embodiment;

[0048] Figure 7 FIG. 4 is a structural block diagram of an electronic device in an embodiment. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] In order to facilitate the clear description of the technical solutions of the embodiments of the present application, in the embodiments of the present application, the words "first" and "second" are used to distinguish the same items or similar items with substantially the same functions and effects. For example, the first instruction and the second instruction are to distinguish different user instructions, and their order is not limited. Those skilled in the art can understand that the words "first" and "second" do not limit the quantity and execution order, and the words "first" and "second" do not necessarily limit them to be different.

[0051] It should be noted that, in this application, words such as "exemplarily" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplarily" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplarily" or "for example" is intended to present related concepts in a specific way.

[0052] In addition, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can mean: a, or b, or c, or a and b, or a and c, or b and c, or a, b and c, where a, b, c can be single or multiple.

[0053] In addition, the terms "including" and "having" and any variations thereof in the embodiments of the present application and the accompanying drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products, or devices.

[0054] The embodiments of the present application disclose an off-grid power control method, apparatus, electronic device, storage medium and product for an energy storage system, so that when the energy storage system is off-grid, the energy storage device can operate normally in the branch line of the energy storage system, thereby improving the flexibility of connecting the energy storage device to the branch line of the energy storage system.

[0055] The embodiment of the present application is described using a household energy storage system as an example, and can also be applied to any other energy storage system of a single-power tree-type distribution network. The embodiment of the present application is not limited thereto. The off-grid power control method of the energy storage system provided in the embodiment of the present application will be exemplarily described below in conjunction with the accompanying drawings.

[0056] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the structure of a household energy storage system in an embodiment. Figure 1 As shown, the household energy storage system includes an energy conversion device 2 (photovoltaic panel), a first user load 3 (street lamp), a second user load 4 (such as household appliances such as air conditioners), and an energy storage device 1. The energy storage device 1 is a small energy storage box that can be mounted on an outdoor wall. Specifically, the photovoltaic panel can convert solar energy into electrical energy during the period of low electricity prices. The energy storage device 1 is used to store the electrical energy and supply it to street lamps and household appliances for use during peak electricity prices, or to supply power when the power grid is out of power / power outage.

[0057] In the application scenario of home energy storage system, please refer to Figure 2 , Figure 2 This is an application scenario diagram of an off-grid power control method for an energy storage system in an embodiment.

[0058] like Figure 2 As shown, the application scenario can be a household power distribution line, which includes a power grid and multiple branch lines connected to the power grid. The household energy storage system includes an energy management system (EMS) 201 in the energy storage system, and the energy storage system also includes at least one energy storage device 203 and multiple branch lines, each branch line is connected to the power grid, and at least one energy storage device 203 is set in at least part of the multiple branch lines. In some embodiments, the energy storage system also includes an on-grid switch 202 and a load 204 on the branch line. The on-grid switch 202 can be set on the bus of the energy storage system, and the energy storage system is connected to the power grid through the on-grid switch 202.

[0059] In an embodiment of the present application, the power grid can be a public power grid or an external power supply network connected to the home, and the branch line is a line channel that distributes electricity to various areas of the home or different electrical devices. EMS201 is used to monitor the status of the energy storage system, including the remaining power, charging and discharging status, and operating status of the energy storage device 203, and accurately control the charging and discharging process of the energy storage device 203 according to the household's electricity demand and the situation of the power grid. EMS201 can be installed in an energy management device at the home bus location, or it can be directly integrated into the energy storage device 203 of the branch line. EMS201 can also be deployed on a cloud server to communicate with the energy storage device 203 or other energy devices in the home line through a communication network.

[0060] Energy storage equipment refers to equipment used to store and release energy. Energy storage equipment in household power distribution lines usually consists of battery packs, battery management systems (BMS), inverters, etc. Battery packs can be lithium-ion batteries, lead-acid batteries, nickel-metal hydride batteries, etc., used to store electrical energy. BMS is responsible for monitoring the status of the battery, such as voltage, current, temperature, etc., to ensure the safe operation of the battery. The inverter converts the DC power stored in the battery into the AC power required for household electricity. Figure 2 As shown, one energy storage device can be connected to the same branch line, such as branch line 1, or multiple energy storage devices can be connected to one branch line, such as branch line 3. It can be understood that no energy storage device may be connected to the branch line, such as branch line 2.

[0061] There are a main line and multiple branch lines in the household line. The main line and each branch line have corresponding line protection settings. The line protection settings refer to a series of pre-set parameter values ​​to protect the safety and stability of the power line in normal operation and fault conditions. Figure 2 In the figure, the current protection setting value of the bus is P, the current protection setting value of branch line 1 is P1, the current protection setting value corresponding to branch line 2 is P2, and the current protection setting value corresponding to branch line 3 is P3. In addition, different user loads 204 can be set on each branch line, such as air conditioners, electric water heaters, etc.

[0062] When each branch line is disconnected from the grid, i.e., in an off-grid situation, the load 204 on the household branch line relies on the discharge of the energy storage device 203 to maintain operation. In order to enable each energy storage device 203 to output the best power, the off-grid power control method of the energy storage system will be described in detail below.

[0063] See also Figure 3 , Figure 3 FIG. 1 is a flow chart of an off-grid power control method for an energy storage system in one embodiment. Figure 3As shown, the method may include the following steps:

[0064] Step 301, when each branch line is disconnected from the power grid, obtain line information of at least one branch line where an energy storage device is located and device information of at least one energy storage device, wherein the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device.

[0065] In the embodiment of the present application, in the off-grid situation, the EMS in the energy storage system obtains the line information of the branch line where the energy storage device is located. As an optional implementation method, the voltage sensor and current sensor installed on the branch line can be used to measure the voltage, current and other parameters of the branch line where the energy storage device is located. The voltage sensor can be a resistor divider type, a capacitor type, a Hall effect type, etc., and the current sensor can be a Hall effect type, a shunt type, etc., which are not specifically limited in the embodiment of the present application. The sensor converts the measured voltage signal and current signal into an electrical signal or a digital signal, and transmits it to the EMS. The EMS can determine the voltage and current conditions of the branch line based on the received signal.

[0066] In some embodiments, the line information also includes the line protection setting of the branch line where the energy storage device is located. Before the process starts, the current protection setting of the bus and all branch lines is stored in the energy storage system to facilitate subsequent calculation of the target discharge power of the energy storage device.

[0067] In some embodiments, the energy storage device information includes the rated discharge current of the energy storage device, and may also include the branch line where the energy storage device is located, the rated charge and discharge power of the energy storage device, the available status of the energy storage device, etc. The battery management system in the energy storage device can monitor various parameters of the energy storage device in real time, such as the discharge voltage, discharge current, remaining power and other parameters of the energy storage device, and send these parameters to the EMS.

[0068] Step 302: determine the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device.

[0069] See also Figure 4 , Figure 4 The flowchart of a method for determining the target discharge power of a target energy storage device in one embodiment is shown. In the embodiment of the present application, the current of the branch line includes the maximum allowable discharge current of the branch line, and the target discharge power of each energy storage device is determined according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, including the following steps:

[0070] Step 401, obtaining a ratio of a rated discharge current of a target energy storage device to a total rated discharge current of all energy storage devices in a target branch line, wherein the target energy storage device is one of the energy storage devices in the energy storage system, and the target branch line is a branch line where the target energy storage device is located;

[0071] In the embodiment of the present application, the method for determining the target discharge power of one of the energy storage devices in the energy storage system is used as an example for explanation, and the EMS can determine the target discharge power of each energy storage device according to the method provided in the embodiment of the present application. As an optional implementation, the EMS can establish a communication connection with the BMS in the target energy storage device, such as using the Modbus communication protocol, the controller area network (Controller Area Network, CAN) bus and other communication protocols, and send a request instruction to the BMS to obtain parameter information such as the rated discharge current of the target energy storage device. Similarly, the above method can be used to obtain the rated discharge current of all energy storage devices in the branch line where the target energy storage device is located, and these rated discharge currents are added to obtain the sum of the rated discharge currents of all energy storage devices in the target branch line, thereby calculating the ratio of the rated discharge current of the target energy storage device to the sum of the rated discharge currents of all energy storage devices in the target branch line.

[0072] In some embodiments, the EMS may establish a database containing information about all energy storage devices in the energy storage system, including the branch line where the target energy storage device is located, rated parameters, etc. When it is necessary to obtain information about the target energy storage device, the EMS may query the database to obtain parameters such as its rated discharge current. Information about the target branch line may also be determined by querying the database to determine the association between the target energy storage device and the branch line, thereby obtaining the rated discharge current of all energy storage devices in the target branch line.

[0073] Step 402, determining the maximum allowable discharge current of the target energy storage device according to the product of the ratio and the maximum allowable discharge current of the target branch line;

[0074] In some embodiments, the current of the branch line also includes an actual discharge current of the branch line, and the method for obtaining the maximum allowable discharge current of the target branch line may include the following steps:

[0075] Step 404, obtaining the load current of the target branch line according to the difference between the sum of the actual discharge currents of all energy storage devices in the target branch line and the actual discharge current of the target branch line;

[0076] Step 405, obtaining the maximum allowable discharge current of the target branch line according to the sum of the current protection setting value of the target branch line and the load current, wherein the current protection setting value is a preset current value.

[0077] The actual sum of discharge currents of all energy storage devices in the target branch line is the sum of discharge currents actually output by all energy storage devices on the current target branch line. Similarly, the BMS of the energy storage device will monitor the actual charge and discharge current and other parameter information of the energy storage battery in real time. The EMS can interact with the BMS to obtain the actual discharge current data of all energy storage devices in the target branch line from the BMS and summarize them to obtain the actual sum of discharge currents of all energy storage devices in the target branch line.

[0078] The actual discharge current of the target branch line includes the discharge current of the energy storage device on the target branch line and the current consumed by other loads connected to the branch line. By installing a high-precision current sensor or smart meter on the target branch line, the actual discharge current of the target branch line can be directly measured. The current sensor or smart meter can communicate with the EMS through a wired connection (such as RS485, Ethernet, etc.) or a wireless connection (such as ZigBee, LoRa, etc.), so that the EMS of the energy storage system can obtain the actual discharge current of the target branch line.

[0079] The load current of the target branch line is obtained by calculating the difference between the sum of the actual discharge currents of all energy storage devices in the target branch line and the actual discharge current of the target branch line, that is, the current consumed by other loads on the target branch line except the energy storage device.

[0080] In the embodiment of the present application, the current protection setting is a pre-set current value, which is usually a safe current upper limit determined based on factors such as the electrical characteristics of the target branch line, the conductor capacity, and the parameters of the protection device. It can prevent the branch line from failing or being damaged due to overcurrent.

[0081] The sum of the current protection setting value of the target branch line and the load current is used as the maximum allowable discharge current of the target branch line. The purpose is to determine the maximum total current that the branch line can withstand based on the current requirements of other loads, so as to set a reasonable upper limit for the discharge current of each energy storage device. When the total current of the energy storage device and other loads on the target branch line does not exceed this maximum allowable discharge current, the safe and stable operation of the branch line can be guaranteed.

[0082] Specifically, the above steps can be expressed by the following formula:

[0083]

[0084] I CTN-dis-MAX =I CTN-P +I loadN (2)

[0085] Among them, I CTN Indicates the actual discharge current of the target branch line, Represents the actual total discharge current of all energy storage devices in the target branch line, I loadN Indicates the load current of the target branch line, I CTN-P is the current protection setting value of the target branch line, I CTN-dis-MAX is the maximum allowable discharge current of the target branch line.

[0086] In the embodiment of the present application, the maximum allowable discharge current of the target energy storage device can be obtained by multiplying the ratio calculated according to step 401 by the maximum allowable discharge current of the target branch line. Exemplarily, it can be expressed by the following formula:

[0087]

[0088] Among them, I CTN-ESS-dis-R Indicates the rated discharge current of the target energy storage device in the target branch line,

[0089] The maximum allowable discharge current.

[0090] By adopting the above embodiment, the current protection constant of the target branch line is introduced in the process of calculating the maximum allowable discharge current of the target branch line, so that the energy storage system has its own line protection function when off-grid, and realizes the functions of branch line overcurrent protection and main line overcurrent protection.

[0091] Step 403 : determining a target discharge power of the target energy storage device according to the maximum allowable discharge current of the target energy storage device and the system voltage of the energy storage system.

[0092] In some embodiments, the system voltage of the energy storage system refers to the operating voltage of the entire energy storage system during operation. The target discharge power of the target energy storage device can be obtained by multiplying the maximum allowable discharge current of the target energy storage device by the system voltage of the energy storage system. The target discharge power of the target energy storage device is the maximum allowable discharge power of the target energy storage device. Specifically, it can be expressed by the following formula:

[0093] P CTN-ESS-N-dis =I CTN-ESS-N-dis *U N (4)

[0094] Among them, I CTN-ESS-N-dis is the maximum allowable discharge current of the target energy storage device, U N is the system voltage of the energy storage system, P CTN-ESS-N-dis Indicates the target discharge power of the target energy storage device.

[0095] The maximum allowable discharge power of each energy storage device calculated by the embodiment of the present application may be different, and the specifications of the energy storage device inverter limit the upper limit of the power adjustment of the energy storage device, so that the energy storage system can use energy storage devices with inverters of different specifications when it is off-grid. When the energy storage system is off-grid, the energy storage device can operate normally in the branch line of the energy storage system.

[0096] Furthermore, since the embodiment of the present application determines the target discharge power according to the information of the branch line where each energy storage device is located, the flexibility of connecting the energy storage device to the branch line of the energy storage system is improved.

[0097] In addition, the wiring of the household power grid distribution line is complex and the protection settings of each branch line are different. The target discharge power determination method of the target energy storage device provided in the embodiment of the present application can determine the maximum allowable discharge power of each energy storage device, and control the discharge power of each energy storage device not to exceed the maximum allowable discharge power, so that when the energy storage device is connected to the household power grid branch line, the line protection will not be triggered and the line will not cause overcurrent, thereby ensuring the normal use of household electrical appliances.

[0098] In some embodiments, before determining the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, the off-grid power control method of the energy storage system further includes:

[0099] Determining the state of the energy storage device according to the remaining power of the energy storage device, wherein the state of the energy storage device includes a discharging state and a standby state;

[0100] Determine whether the energy storage device performs a discharge operation according to a preset energy storage device execution strategy and the state of the energy storage device, wherein the preset energy storage device execution strategy includes determining that the energy storage device performs a discharge operation when the state of the energy storage device is a discharge state.

[0101] In the embodiment of the present application, the EMS of the energy storage system obtains the remaining power of each energy storage device before determining the target discharge power of each energy storage device. When the remaining power is less than a preset threshold, it is determined that the corresponding energy storage device is in a standby state. The energy storage device in the standby state can be charged, but cannot be discharged, that is, the energy storage device in the standby state is considered to be an unavailable device in an off-grid scenario. The EMS of the energy storage system will not take the unavailable energy storage device into consideration when determining the target discharge power of the energy storage device. It is understandable that when the energy storage device is in a fault state, it is also an unavailable device. For example, when the EMS receives a fault signal uploaded by the energy storage device, it determines that the energy storage device is in a fault state.

[0102] When the remaining power of the energy storage device is greater than or equal to a preset threshold, it is determined that the corresponding energy storage device is in a discharging state. The energy storage device can provide electrical energy to an external load in the discharging state. When the energy storage device is in a discharging state, it is determined that the energy storage device performs a discharging operation. Then, the EMS of the energy storage system determines the target discharge power of the energy storage device and sends the target discharge power to the energy storage device.

[0103] By adopting the above embodiment, the EMS of the energy storage system only calculates the target discharge power of the available energy storage equipment, which can save the computing resources of the energy storage system.

[0104] Step 303: Control the discharge power of at least one energy storage device to be the corresponding target discharge power.

[0105] In an embodiment of the present application, after the EMS of the energy storage system determines the target discharge power of the energy storage device, the target discharge power is sent to each energy storage device, and the inverter of each energy storage device adjusts the output parameters according to the corresponding target discharge power so that the discharge power of the energy storage device is the corresponding target discharge power.

[0106] In some embodiments, the EMS can adjust the discharge parameters of the energy storage device by communicating with the BMS of the energy storage device. For example, the BMS of the energy storage device can adjust the output voltage or current limit of the battery to control the discharge power of the energy storage device by changing the voltage or current.

[0107] In some other embodiments, the EMS can also perform feedback control based on the difference between the actual discharge power of the energy storage device and the target discharge power. For example, the EMS can use a proportional-integral-derivative (PID) control algorithm to automatically adjust control parameters according to power deviation to achieve fast and accurate power control.

[0108] The off-grid power control method for an energy storage system provided in an embodiment of the present application determines and controls the target discharge power of each energy storage device by acquiring line information and device information of the branch line where each energy storage device is located when the energy storage system is off-grid, so that when the energy storage system is off-grid, the energy storage device can operate normally in the branch line of the energy storage system, and the target discharge power is determined based on the information of the branch line where each energy storage device is located, thereby improving the flexibility of connecting the energy storage device to the branch line of the energy storage system.

[0109] See also Figure 5 , Figure 5 FIG. 1 is a schematic diagram of the overall flow of an off-grid power control method for an energy storage system in an embodiment. Figure 5As shown in the figure, all line protection settings in the household distribution line are pre-entered and stored in the energy storage system. The monitoring equipment in the power grid (such as smart meters, sensors, etc.) is used to detect whether there is a new energy storage device connected to the power grid. The monitoring equipment can monitor the current and voltage changes in the power grid. When a new energy storage device is connected to the power grid, it will cause these electrical parameters to change, which will be captured by the monitoring equipment. In addition to monitoring electrical parameters, smart meters, sensors and other monitoring equipment also have communication functions and can send corresponding alarm signals or prompt information to the EMS.

[0110] When energy storage devices are connected to the home power grid, they may cause transient fluctuations in the power grid. In order to stabilize the operation of the power grid, the transient power of the energy storage devices needs to be distributed locally. Local distribution refers to power distribution at the local location of the energy storage device, without relying on remote centralized control. It is usually achieved through the inverter and related algorithms of the energy storage device. When the energy storage device controls and distributes transient power locally, so that the voltage and frequency of the power grid are kept within a relatively stable range, that is, after the fluctuation balance of the power grid is achieved, the EMS of the energy storage system distributes steady-state power to the energy storage device.

[0111] When it is detected that the energy storage device is connected to the grid, the EMS of the energy storage system identifies the branch line to which the energy storage device belongs. For example, the branch line to which the energy storage device is connected can be determined through grid topology information and electrical parameter measurements. It can also make judgments using data from smart meters, electrical characteristics of the lines (such as impedance), and the grid connection relationship database.

[0112] In an embodiment of the present application, it is necessary to judge the on-grid or off-grid state of the energy storage system. When it is determined that the energy storage system is in an off-grid state, the EMS of the energy storage system calculates the target discharge power of the energy storage device and sends the calculation result to each energy storage device, controlling the discharge power of at least one energy storage device to be the corresponding target discharge power.

[0113] In some embodiments, the energy storage system further includes an on-grid switch, which is disposed on a bus of the energy storage system. The energy storage system is connected to the power grid via the on-grid switch. The off-grid power control method of the energy storage system further includes:

[0114] Determine whether the target indication information indicates that the on-grid and off-grid switch is in a disconnected state and whether the grid voltage state does not meet a preset condition, wherein the preset condition is that the grid voltage is within a range of a preset second threshold value and a preset third threshold value and the duration is greater than a preset fourth threshold value, and the third threshold value is greater than the second threshold value, and the target indication information is used to indicate the working state of the on-grid and off-grid switch, and the working state includes a disconnected state or a closed state;

[0115] When the target indication information indicates that the on-grid and off-grid switch is in an off state and the grid voltage state does not meet the preset conditions, it is determined that each branch line is disconnected from the grid.

[0116] In some embodiments, the target indication information is information received by the EMS in the energy storage system through communication. The detection of the working state of the on-grid and off-grid switch may include but is not limited to the following methods: First, through the electrical signal monitoring method, the voltage signal at both ends of the switch or the current signal passing through is monitored by a voltage or current sensor, and when there is an obvious voltage difference or the current is zero, the on-grid and off-grid switch is judged to be in a disconnected state; second, a position sensor monitoring method is adopted, such as a mechanical position sensor or a photoelectric position sensor, and the switch state is judged by sensing the mechanical position change of the switch or blocking the light path; third, according to the control system feedback method, including the energy storage system's own control system feedback and remote monitoring system feedback, the working state of the on-grid and off-grid switch is determined by checking the control system signal. In some embodiments, due to switch failure, signal transmission error and other reasons, the target indication information received by the EMS cannot accurately indicate the on-grid and off-grid state of the system. Therefore, in the embodiment of the present application, the on-grid and off-grid state of the energy storage system is further judged in combination with the state of the grid voltage.

[0117] The preset second threshold value and the preset third threshold value are preset voltage values, and these two threshold values ​​determine the normal range of the grid voltage. The third threshold value is greater than or equal to the second threshold value, and the two together constitute a voltage interval. For example, if the rated voltage of the grid is 220V, the second threshold value can be set to 198V and the third threshold value can be set to 242V, indicating that the grid voltage is considered normal between 198V and 242V. The preset fourth threshold value specifies the time requirement for the grid voltage to be within the normal range, for example, 10 seconds. Only when the grid voltage is within the normal range for a duration greater than the preset fourth threshold value, the grid voltage state is considered to meet the preset conditions. In other words, if the grid voltage is not within the preset normal range, or although it is within the normal range but the duration is less than or equal to the preset fourth threshold value, it is considered that the grid voltage state does not meet the preset conditions.

[0118] By adopting the above embodiment, by simultaneously considering multiple parameters such as the indication information of the working status of the on-grid and off-grid switch and the grid voltage status, the connection status of the energy storage system and the grid can be determined more comprehensively, thereby more accurately judging the on-grid and off-grid status of the energy storage system, reducing the probability of misjudgment of the on-grid and off-grid status of the energy storage system.

[0119] When it is determined that the energy storage system is in an off-grid state, whether the energy storage device performs a discharge operation is determined based on a pre-set energy storage device execution strategy and the state of the energy storage device. That is, when the EMS of the energy storage system determines that the target energy storage device is an available device, its target discharge power is further determined. The embodiments of the present application are not described in detail here.

[0120] In some embodiments, the off-grid power control method of the energy storage system further includes:

[0121] detecting whether an available quantity of at least one energy storage device in the energy storage system changes;

[0122] When a change in the available quantity is detected, the target discharge power of each energy storage device is re-determined.

[0123] The system state change of the energy storage system is the change in the available number of energy storage devices in the energy storage system. When the available number of energy storage devices changes, the energy storage device inverter re-controls and distributes the transient power. After the fluctuation is balanced, the EMS of the energy storage system determines whether to recalculate the target discharge power of the energy storage device according to the preset conditions, wherein the preset conditions are the judgment conditions for the change in the available number of energy storage devices. After the EMS recalculates the target discharge power, it distributes the steady-state power to the energy storage device again, and controls the discharge power of at least one energy storage device to be the corresponding target discharge power.

[0124] In the embodiment of the present application, by detecting the change in the available number of energy storage devices in the energy storage system, once the change in the available number is detected, the target discharge power of each energy storage device is re-determined, so that the energy storage system can dynamically calculate and adjust the target discharge power of the energy storage device according to the real-time situation of the energy storage device connected to the branch line, thereby improving the reliability and adaptability of the system.

[0125] In an embodiment of the present application, detecting whether the available quantity of at least one energy storage device in the energy storage system changes includes:

[0126] In the case where it is detected that at least one energy storage device is in a fault state, determining that the available quantity of at least one energy storage device has changed; or,

[0127] When it is detected that the remaining power of at least one energy storage device is less than a preset first threshold, determining that the available quantity of at least one energy storage device has changed; or,

[0128] In the case of detecting a change in the state of the power grid, determining that the available quantity of at least one energy storage device has changed, wherein the state of the power grid includes the energy storage device being unplugged from the power grid and / or newly plugged into the power grid.

[0129] In some embodiments, the inverter of the energy storage device can send information such as fault code and fault description to the EMS through the communication protocol. After receiving the fault information uploaded by the energy storage device, the EMS can determine that the energy storage device is in a fault state. In addition, it is also possible to determine whether the energy storage device has failed by monitoring the changes in the output voltage and current parameters of the energy storage device in real time. When the energy storage device is in a normal state, its output voltage and current should fluctuate within a certain range. If an abnormal voltage drop, zero current or abnormal fluctuation is detected, it may indicate that the energy storage device has failed.

[0130] When it is detected that the remaining power of the energy storage device is less than the preset first threshold, it is determined that the corresponding energy storage device is in a standby state, and the energy storage device in the standby state is an unavailable device, that is, the available quantity of the energy storage device has changed, wherein the preset first threshold is a preset power value, which is used to determine whether the energy storage device enters the standby state. In some embodiments, the remaining power of the energy storage device can be monitored by the battery management system BMS, and the remaining power information can be sent to the EMS.

[0131] In some embodiments, when a newly added energy storage device without faults is detected in the home power grid through communication, and the remaining power is greater than a preset first threshold, it is determined that the energy storage device is newly inserted into the power grid. For the newly inserted energy storage device in the power grid, it is necessary to first identify the branch line to which the energy storage device belongs, and then calculate the target discharge power; accordingly, when the EMS cannot communicate with the energy storage device, it is determined that the energy storage device is unplugged from the home power grid. The communication device is used for the EMS to communicate with the energy storage device to detect the status of the energy storage device in the power grid. The communication device may include a smart meter, a gateway device, an RS-485 communication module, an Ethernet communication module, a Wi-Fi communication module, a Bluetooth communication module, a cellular network communication module, etc.

[0132] The embodiments of the present application determine the available number of energy storage devices by detecting the remaining power, fault status, and status of the power grid of the energy storage device, thereby improving the accuracy of detecting the available number of energy storage devices.

[0133] By adopting the above embodiment, in an off-grid situation, by calculating the target discharge power of each energy storage device and controlling the discharge power of at least one energy storage device to be the corresponding target discharge power, the maximum allowable discharge power of each energy storage device can be different, and the specifications of the energy storage device inverter limit the upper limit of the power adjustment of the energy storage device, so that the energy storage system can use energy storage devices with inverters of different specifications when off-grid. In addition, by determining the maximum allowable discharge power of each energy storage device and controlling the discharge power of each energy storage device not to exceed the maximum allowable discharge power, when the energy storage device is connected to the branch line of the household power grid, the line protection will not be triggered and the line will not cause overcurrent, thereby ensuring the normal use of household electrical appliances. In addition, by adopting the method provided in the embodiment of the present application, the energy storage device can operate normally in the branch line of the energy storage system, and the target discharge power is determined according to the information of the branch line where each energy storage device is located, thereby improving the flexibility of connecting the energy storage device to the branch line of the energy storage system.

[0134] See also Figure 6 , Figure 6 FIG. 1 is a block diagram of an off-grid power control device for an energy storage system in an embodiment. Figure 6 As shown, the off-grid power control device 600 of the energy storage system may include: an information acquisition module 610 , a power determination module 620 , and a control module 630 .

[0135] The information acquisition module 610 is used to acquire the line information of the branch line where at least one energy storage device is located and the device information of at least one energy storage device when each branch line is disconnected from the power grid, wherein the line information includes the current of the branch line and the device information includes the rated current of the energy storage device;

[0136] The power determination module 620 is used to determine the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device;

[0137] The control module 630 is used to control the discharge power of at least one energy storage device to be the corresponding target discharge power.

[0138] In some embodiments, the power determination module 620 is specifically configured to:

[0139] Obtaining a ratio of a rated discharge current of a target energy storage device to a total rated discharge current of all energy storage devices in a target branch line, wherein the target energy storage device is one of the energy storage devices in the energy storage system, and the target branch line is a branch line where the target energy storage device is located;

[0140] Determine the maximum allowable discharge current of the target energy storage device according to the product of the ratio and the maximum allowable discharge current of the target branch line;

[0141] The target discharge power of the target energy storage device is determined according to the maximum allowable discharge current of the target energy storage device and the system voltage of the energy storage system.

[0142] In some embodiments, the power determination module 620 is specifically configured to:

[0143] Obtaining the load current of the target branch line according to the difference between the sum of the actual discharge currents of all energy storage devices in the target branch line and the actual discharge current of the target branch line;

[0144] The maximum allowable discharge current of the target branch line is obtained according to the sum of the current protection setting value of the target branch line and the load current, and the current protection setting value is a preset current value.

[0145] In some embodiments, the information acquisition module 610 is further used to:

[0146] detecting whether an available quantity of at least one energy storage device in the energy storage system changes;

[0147] When a change in the available quantity is detected, the target discharge power of each energy storage device is re-determined.

[0148] In some embodiments, the information acquisition module 610 is further used to:

[0149] In the case where it is detected that at least one energy storage device is in a fault state, determining that the available quantity of at least one energy storage device has changed; or,

[0150] When it is detected that the remaining power of at least one energy storage device is less than a preset first threshold, determining that the available quantity of at least one energy storage device has changed; or,

[0151] In the case of detecting a change in the state of the power grid, determining that the available quantity of at least one energy storage device has changed, wherein the state of the power grid includes the energy storage device being unplugged from the power grid and / or newly plugged into the power grid.

[0152] In some embodiments, the information acquisition module 610 is specifically used to:

[0153] Determining the state of the energy storage device according to the remaining power of the energy storage device, where the state of the energy storage device includes a discharge state and a standby state;

[0154] Determine whether the energy storage device performs a discharge operation according to a preset energy storage device execution strategy and the state of the energy storage device, wherein the preset energy storage device execution strategy includes determining that the energy storage device performs a discharge operation when the state of the energy storage device is a discharge state.

[0155] The description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

[0156] See also Figure 7 , Figure 7 FIG. 1 is a structural block diagram of an electronic device in an embodiment. Figure 7 As shown, the electronic device 700 may include: a processor 710 , a memory 720 , and a bus 730 .

[0157] The processor 710 calls the executable program code stored in the memory 720 to execute any off-grid power control method disclosed in the embodiment of the present application. Those skilled in the art can understand that Figure 7 The electronic device structure shown in the figure does not constitute a limitation on the electronic device. The electronic device may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0158] The processor 710 is used to execute, when each branch line is disconnected from the power grid, obtaining line information of a branch line where at least one energy storage device is located and device information of at least one energy storage device, wherein the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device;

[0159] According to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, the target discharge power of each energy storage device is determined; the discharge power of at least one energy storage device is controlled to be the corresponding target discharge power, etc. For details, please refer to the detailed description in the method example, which will not be repeated here.

[0160] In the embodiment of the present application, the processor 710 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiment of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0161] The memory 720 can be used to store software programs and modules. The processor 710 executes various functional applications and data processing of the electronic device by running the software programs and modules stored in the memory 720. The memory 720 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function, etc.; the data storage area can store data created according to the use of the electronic device, etc. In addition, the memory 720 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0162] In the embodiment of the present application, the processor 710 and the memory 720 are connected via a bus 730. Figure 7 The connections between other components are shown in bold lines, which are only for illustration and are not intended to be limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 7 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0163] An embodiment of the present application discloses a computer-readable storage medium storing a computer program, wherein the computer program implements the methods described in the above embodiments when executed by a processor.

[0164] An embodiment of the present application discloses a computer program product, which includes a non-transitory computer-readable storage medium storing a computer program, and the computer program can be executed by a processor to implement the methods described in the above embodiments.

[0165] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium, and when the program is executed, it can include the processes of the embodiments of the above-mentioned methods. The storage medium can be a disk, an optical disk, a ROM, etc.

[0166] As used herein, any reference to memory, storage, database, or other medium may include nonvolatile and / or volatile memory. Suitable nonvolatile memory may include ROM, programmable ROM (Programmable ROM, PROM), erasable PROM (Erasable PROM, EPROM), electrically erasable PROM (Electrically Erasable PROM, EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which is used as an external cache memory. By way of illustration and not limitation, RAM may be in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), memory bus direct RAM (RDRAM) and direct memory bus dynamic RAM (DRDRAM).

[0167] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. Those skilled in the art should also be aware that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application. It should be noted that "multiple" in the present application includes "two or more".

[0168] In the various embodiments of the present application, it should be understood that the size of the serial numbers of the above-mentioned processes does not necessarily 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.

[0169] The units described above 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.

[0170] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0171] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0172] The above is a detailed introduction to the off-grid power control method, device, electronic device, storage medium and product of an energy storage system disclosed in the embodiment of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those of ordinary skill in the art, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. An off-grid power control method for an energy storage system, characterized in that: An energy management system applied to the energy storage system, the energy storage system further comprising at least one energy storage device and a plurality of branch lines, each branch line being respectively connected to a power grid, the at least one energy storage device being arranged in at least some of the branch lines among the plurality of branch lines, the method comprising: When each branch line is disconnected from the power grid, obtaining line information of the branch line where the at least one energy storage device is located and device information of the at least one energy storage device, wherein the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device; Determine the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device; The discharge power of the at least one energy storage device is controlled to be the corresponding target discharge power.

2. The method according to claim 1, characterized in that The current of the branch line includes the maximum allowable discharge current of the branch line, and the target discharge power of each energy storage device is determined according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, including: Obtaining a ratio of a rated discharge current of a target energy storage device to a total rated discharge current of all energy storage devices in a target branch line, wherein the target energy storage device is one of the energy storage devices in the energy storage system, and the target branch line is a branch line where the target energy storage device is located; Determine the maximum allowable discharge current of the target energy storage device according to the product of the ratio and the maximum allowable discharge current of the target branch line; The target discharge power of the target energy storage device is determined according to the maximum allowable discharge current of the target energy storage device and the system voltage of the energy storage system.

3. The method according to claim 2, characterized in that The current of the branch line also includes an actual discharge current of the branch line, and determining the maximum allowable discharge current of the target energy storage device according to the product of the ratio and the maximum allowable discharge current of the target branch line includes: Obtaining a load current of the target branch line according to a difference between a sum of actual discharge currents of all energy storage devices in the target branch line and an actual discharge current of the target branch line; The maximum allowable discharge current of the target branch line is obtained according to the sum of the current protection setting value of the target branch line and the load current, and the current protection setting value is a preset current value.

4. The method according to claim 1, characterized in that: The method further comprises: Detecting whether an available quantity of at least one energy storage device in the energy storage system changes; When a change in the available quantity is detected, the target discharge power of each energy storage device is re-determined.

5. The method according to claim 4, characterized in that The detecting whether the available quantity of at least one energy storage device in the energy storage system changes includes: In the case where it is detected that at least one of the energy storage devices is in a fault state, determining that the available quantity of the at least one energy storage device changes; or, In the case where it is detected that the remaining power of at least one of the energy storage devices is less than a preset first threshold, determining that the available quantity of the at least one energy storage device has changed; or, In the case of detecting that a state of the power grid has changed, determining that the available quantity of the at least one energy storage device has changed, wherein the state of the power grid includes the energy storage device being unplugged from the power grid and / or newly inserted into the power grid.

6. The method according to claim 1, characterized in that The energy storage system further includes an on-grid and off-grid switch, which is disposed on a bus of the energy storage system, and the energy storage system is connected to the power grid via the on-grid and off-grid switch. The method further includes: determining whether the target indication information indicates that the grid-connected and off-grid switch is in a disconnected state and whether the grid voltage state does not meet a preset condition, wherein the preset condition is that the grid voltage is within a range of a preset second threshold value and a preset third threshold value and the duration is greater than a preset fourth threshold value, and the third threshold value is greater than the second threshold value, and the target indication information is used to indicate the working state of the grid-connected and off-grid switch, and the working state includes the disconnected state or the closed state; When the target indication information indicates that the on-grid and off-grid switch is in the disconnected state and the grid voltage state does not satisfy a preset condition, it is determined that each branch line is disconnected from the grid.

7. The method according to claim 1, characterized in that Before determining the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device, the method further includes: Determining the state of the energy storage device according to the remaining power of the energy storage device, the state of the energy storage device including a discharging state and a standby state; Determine whether the energy storage device performs a discharge operation according to a preset energy storage device execution strategy and the state of the energy storage device, wherein the preset energy storage device execution strategy includes determining that the energy storage device performs a discharge operation when the state of the energy storage device is a discharge state.

8. An off-grid power control device for an energy storage system, characterized in that: An energy management system applied to the energy storage system, the energy storage system further comprising at least one energy storage device and a plurality of branch lines, each branch line being respectively connected to a power grid, the at least one energy storage device being arranged in at least some of the branch lines among the plurality of branch lines, the device comprising: An information acquisition module, configured to acquire, when each branch line is disconnected from the power grid, line information of the branch line where the at least one energy storage device is located and device information of the at least one energy storage device, wherein the line information includes the current of the branch line, and the device information includes the rated current of the energy storage device; A power determination module, used to determine the target discharge power of each energy storage device according to the line information of the branch line where each energy storage device is located and the device information of the corresponding energy storage device; The control module is used to control the discharge power of the at least one energy storage device to be the corresponding target discharge power.

9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the processor implements the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

11. A computer program product, comprising a non-transitory 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 7 is implemented.

Images