Grid-connected and off-network switching method and device, energy storage system and storage medium

Abstract

The embodiment of the invention discloses an on-grid and off-grid switching method and device, an energy storage system and a storage medium, under the condition that a target on-grid and off-grid switching condition is met or a target switching instruction sent by terminal equipment is received, control equipment firstly sends a standby instruction to each piece of inversion energy storage equipment, when the inverter energy storage devices are charged or discharged, the inverter energy storage devices stop receiving or outputting electric energy, and then the first switching instruction is sent to the power distribution device, so that grid-connected and off-grid switching actions are prevented from being performed when the inverter energy storage devices are charged and discharged, reverse current is prevented from being generated, impact on a load caused by sudden change of current or voltage is reduced, and the service life of the inverter energy storage devices is prolonged. Meanwhile, a protection mechanism is prevented from being triggered, and the safety and stability of the energy storage system are improved. After the first switching instruction is sent to the power distribution equipment, the control equipment controls the inversion energy storage equipment to enter the target grid-connected and off-grid mode, so that the inversion energy storage equipment outputs or receives electric energy again, signal mutation is avoided, and the safety and stability of the system are further improved.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a grid-connected and off-grid switching method, device, energy storage system and storage medium. Background Art

[0002] Microgrids can effectively organize a variety of loads and energy storage devices, and can be connected to the external large grid through the Point of Common Coupling (PCC), or can be operated independently off the grid. With the development of microgrid technology, its grid connection mode, energy storage devices and load composition are complex and changeable. How to ensure the stability of the microgrid system during the switching process of on-grid and off-grid modes has become a technical difficulty that needs to be solved urgently. Summary of the invention

[0003] The embodiments of the present application disclose a grid-connected and off-grid switching method, device, energy storage system and storage medium, which can ensure the stability of the energy storage system.

[0004] The embodiment of the present application discloses a method for switching between a grid and an off-grid, which is applied to a control device, wherein the control device is respectively connected to one or more inverter energy storage devices for communication. The method includes:

[0005] In response to meeting the target and off-grid switching conditions, or in the case of receiving a target switching instruction sent by the terminal device, sending a standby instruction to the one or more inverter energy storage devices, wherein the target switching instruction is generated by the terminal device in response to the target switching operation, and the standby instruction is used to instruct each of the inverter energy storage devices to enter a standby state, in which the inverter energy storage device does not perform charging and discharging operations;

[0006] When it is determined that each of the inverter energy storage devices enters the standby state, a first switching instruction is sent to the power distribution device, wherein the first switching instruction is used to instruct the power distribution device to control the grid-connected and off-grid switches of the power distribution device to perform a first switching action corresponding to the target grid-connected and off-grid mode;

[0007] Control the one or more inverter energy storage devices to operate in the target on-grid and off-grid mode.

[0008] As an optional implementation, the method further includes:

[0009] If it is detected that the power supply voltage input by the power supply system does not belong to the voltage range corresponding to the on-grid or off-grid mode in which the one or more inverter energy storage devices are currently located, it is determined that the target on-grid or off-grid switching condition is met.

[0010] As an optional implementation, the method further includes:

[0011] In the case of being in the automatic switching mode, if a target switching instruction sent by a terminal device is received, the target switching instruction is not responded to;

[0012] or,

[0013] In the case of the manual switching mode, it is not detected whether the supply voltage does not belong to the voltage range corresponding to the grid-connected or off-grid mode in which the one or more inverter energy storage devices are currently located.

[0014] As an optional implementation, the method further includes:

[0015] Determine status display information and send the status display information to a terminal device so that the terminal device displays the status display information; the status display information includes the current on-grid and off-grid mode of the one or more inverter energy storage devices, and / or the working status of the power supply system.

[0016] As an optional implementation, after sending the first switching instruction to the power distribution device and before controlling the one or more inverter energy storage devices to operate in the target on-grid and off-grid mode, the method includes:

[0017] Determining whether the inverter energy storage device is successfully switched to the target off-grid mode according to the first input voltage of the load;

[0018] If it is determined that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode, a second switching instruction is sent to the power distribution device; the second switching instruction is used to instruct the power distribution device to control the on-grid and off-grid switch to perform a second switching action, and the second switching action is different from the first switching action;

[0019] If the current time is equal to the preset time from the time when the second switching instruction is sent to the power distribution device, then the power distribution device is restarted. implement The step of sending a first switching instruction to the power distribution equipment, until it is determined that the inverter energy storage device is successfully switched to the target off-grid mode according to the first input voltage of the load.

[0020] As an optional implementation, the method further includes:

[0021] If the first input voltage does not belong to the voltage range corresponding to the target on-grid and off-grid mode, it is determined that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode.

[0022] As an optional implementation manner, judging whether the inverter energy storage device is successfully switched to the target on-grid and off-grid mode according to the first input voltage received by the load includes:

[0023] According to the first input voltage and the switching state of the on-grid and off-grid switch, it is determined whether the inverter energy storage device is successfully switched to the target on-grid and off-grid mode.

[0024] As an optional implementation manner, the target on-grid and off-grid mode is a on-grid mode;

[0025] After sending a standby instruction to one or more inverter energy storage devices and before sending a first switching instruction to a power distribution device, the method includes:

[0026] Determining whether the second input voltage of the load falls within a preset power outage range;

[0027] The sending a first switching instruction to the power distribution equipment includes:

[0028] If it is determined that the second input voltage belongs to the preset power outage range, a first switching instruction is sent to the power distribution equipment.

[0029] The embodiment of the present application discloses a grid-connected and off-grid switching device, which is applied to a control device, wherein the control device is respectively connected to one or more inverter energy storage devices for communication, and the device includes:

[0030] A first sending module, configured to send a standby instruction to the one or more inverter energy storage devices in response to meeting the target off-grid switching condition or receiving a target switching instruction sent by a terminal device, wherein the target switching instruction is generated by the terminal device in response to the target switching operation, and the standby instruction is used to instruct each of the inverter energy storage devices to enter a standby state, in which the inverter energy storage device does not perform a charge or discharge operation;

[0031] A second sending module is used to send a first switching instruction to the power distribution device when it is determined that each of the inverter energy storage devices enters the standby state, wherein the first switching instruction is used to instruct the power distribution device to control the grid-connected and off-grid switches of the power distribution device to perform a first switching action corresponding to the target grid-connected and off-grid mode;

[0032] A control module is used to control the one or more inverter energy storage devices to operate in the target on-grid and off-grid mode.

[0033] The present application discloses an energy storage system, including:

[0034] One or more inverter energy storage devices, wherein the inverter energy storage devices are used to perform charging and discharging operations;

[0035] A power distribution device, comprising an on-grid and off-grid switch, wherein the power distribution device is used to control the on-grid and off-grid switch to perform a first switching action;

[0036] a memory, wherein a computer program is stored in the memory;

[0037] A control device, when the control device executes the computer program, the control device implements any one of the on-grid and off-grid switching methods disclosed in the embodiments of the present application.

[0038] An embodiment of the present application discloses a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, any one of the on-grid and off-grid switching methods disclosed in the embodiment of the present application is implemented.

[0039] Compared with the related art, the embodiments of the present application have the following beneficial effects:

[0040] The embodiments of the present application provide a method, device, energy storage system and storage medium for switching between grid and off-grid. When the target grid and off-grid switching conditions are met or the target switching instruction sent by the terminal device is received, the control device first sends a standby instruction to each inverter energy storage device to stop each inverter energy storage device from receiving or outputting electric energy, and then sends a first switching instruction to the power distribution device, thereby avoiding the operation of the grid-connected and off-grid switch when the inverter energy storage device is performing charging and discharging operations, preventing the generation of reverse current, reducing the impact on the load caused by sudden changes in current or voltage, and avoiding triggering the protection mechanism, thereby improving the safety and stability of the energy storage system. After sending the first switching instruction to the power distribution device, the control device will control the inverter energy storage device to enter the target grid-connected and off-grid mode, enabling the inverter energy storage device to output or receive electric energy again, avoiding signal mutations, and further improving the safety and stability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will describe the technical solutions required in the embodiments. Attached photos For a brief introduction, it is obvious that 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 any creative work.

[0042] Figure 1 This is an application scenario diagram of a method for switching between an on-grid and an off-grid mode disclosed in an embodiment of the present application;

[0043] Figure 2 It is a flowchart of a method for switching between grid and off-grid that is disclosed in an embodiment of the present application;

[0044] Figure 3 This is a schematic diagram of an on-grid and off-grid control interface disclosed in an embodiment of the present application;

[0045] Figure 4 This is a schematic diagram of a process of displaying and disconnecting a network control interface disclosed in an embodiment of the present application;

[0046] Figure 5is a schematic diagram of first prompt information displayed by a terminal device disclosed in an embodiment of the present application;

[0047] Figure 6 is a schematic diagram of second prompt information displayed by a terminal device disclosed in an embodiment of the present application;

[0048] Figure 7 is a schematic diagram of the connection relationship of another energy storage system disclosed in an embodiment of the present application;

[0049] Figure 8 It is a schematic diagram of another on-grid and off-grid control interface disclosed in an embodiment of the present application;

[0050] Fig. 9 It is a flow chart of another on-grid and off-grid switching method disclosed in an embodiment of the present application;

[0051] Fig.10 is a schematic diagram of a first failure prompt message displayed by a terminal device disclosed in an embodiment of the present application;

[0052] Fig.11 is a schematic diagram of a second failure prompt message displayed by a terminal device disclosed in an embodiment of the present application;

[0053] Fig.12 It is a flowchart of another on-grid and off-grid switching method disclosed in an embodiment of the present application;

[0054] Fig.13 It is a schematic diagram of a process of manually switching to a grid-connected mode disclosed in an embodiment of the present application;

[0055] Fig.14 It is a schematic diagram of a process of manually switching to an off-grid mode disclosed in an embodiment of the present application;

[0056] Fig.15 It is a schematic diagram of a process of automatically switching to a grid-connected mode disclosed in an embodiment of the present application;

[0057] Fig.16 It is a schematic diagram of a process of automatically switching to an off-grid mode disclosed in an embodiment of the present application;

[0058] Fig.17 It is a structural schematic diagram of a grid-connected and off-grid switching device disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0059] 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.

[0060] It should be noted that 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 including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0061] In the related art, many energy storage systems can only work in pure grid-connected or pure off-grid mode. In pure grid-connected mode, the energy storage system relies on the grid to power the load. When the grid fails (such as power outages or voltage fluctuations), the energy storage system will immediately stop connecting to the grid to supply power, causing the load to be powered off. In pure off-grid mode, the energy storage system relies on its own energy storage device to power the load. When the energy storage device is exhausted, it cannot power the load, causing the load to be powered off. It can be seen that the energy storage system cannot achieve on-grid and off-grid mode switching.

[0062] Although, there are energy storage systems that can work in grid-connected mode or off-grid mode. For example, the inverter energy storage device of the energy storage system detects whether the grid is in a fault state. If it is determined that the grid is in a fault state, the inverter energy storage device is controlled to work in the off-grid mode. If it is determined that the grid is in a normal state, the inverter energy storage device is controlled to work in the grid-connected mode. However, it is found in practice that in the process of mode switching, that is, switching from grid-connected mode to off-grid mode, or from off-grid mode to grid-connected mode, the overcurrent and overvoltage protection of the energy storage system may be triggered, resulting in poor stability of the energy storage system during the switching process between grid-connected and off-grid modes. This may be because when the inverter energy storage device detects a change in the state of the grid, it directly controls the inverter energy storage device to work in the corresponding grid-connected and off-grid mode, resulting in a sudden change in the voltage and current of the energy storage system, triggering the overcurrent and overvoltage protection of the energy storage system.

[0063] The embodiments of the present application disclose a grid-connected and off-grid switching method, device, energy storage system and storage medium, which can ensure the stability of the energy storage system.

[0064] Figure 1 The application scenario diagram of the on-grid and off-grid switching method provided in the embodiment of the present application is shown. Figure 1 As shown, the energy storage system can It includes a control device 110, a power distribution device 120, and one or more inverter energy storage devices 130. Energy equipment 130 can be used to convert electrical energy into other forms of energy by physical or chemical means and store it, and convert the stored energy into electrical energy when needed. The power distribution equipment 120 can be used to conduct the power transmission channel between the load 150 and the power supply system (not shown in the figure), and the power transmission channel between the inverter energy storage device 130 and the power supply system. The control device 110 is used to control the inverter energy storage device 130 to perform charging and discharging operations, and control the power distribution equipment 120 to control the off-grid switch to perform switching operations.

[0065] Optionally, the control device 110 may include an EMS (Energy Management System). Optionally, the control device 110 may be a local control device, that is, the control and data processing of the control device 110 occur inside the building without relying on an external server or cloud platform.

[0066] Optionally, the power distribution device 120 may be a power distribution box.

[0067] Optionally, please continue to refer to Figure 1 The power distribution equipment 120 may include an on-grid and off-grid switch 121 and a control unit 122. The on-grid and off-grid switch 121 is connected to the power supply system 140, the load 150 and the inverter energy storage device 130 respectively. The on-grid and off-grid switch 121 is used to open or disconnect the electrical connection channel between the power supply system 140 and the load 150, and to open or disconnect the electrical connection channel between the power supply system 140 and the inverter energy storage device 130. The control unit 122 can be used to control the on-grid and off-grid switch 121 to perform a switching action. The switching action may include an opening action and a closing action. The on-grid and off-grid switch 121 performs an opening action, that is, the on-grid and off-grid switch 121 is in an off state, the electrical connection channel between the power supply system 140 and the load 150 is disconnected, and the electrical connection channel between the power supply system 140 and each inverter energy storage device 130 is disconnected. The on-grid and off-grid switch 121 performs a closing action, that is, the on-grid and off-grid switch 121 is in a closed state, the electrical connection channel between the power supply system 140 and the load 150 is connected, and the electrical connection channel between the power supply system 140 and each inverter energy storage device 130 is connected.

[0068] For example, please continue to refer to Figure 1 Each inverter energy storage device 130 may include an inverter 131 and an energy storage device 132. The energy storage device 132 is used to store or release electrical energy, and the inverter 131 is used to convert the direct current output by the energy storage device 132 into alternating current to power the load 150 or input it into the power supply system 140. Exemplarily, the energy storage device 132 may include, but is not limited to, a chemical battery.

[0069] In another example, please refer to Figure 1The inverter energy storage device 130 may also include a first power generation device 133, which can convert light energy and / or wind energy into electrical energy, and transmit the electrical energy to the energy storage device 132 for storage through the inverter 131, or transmit it to the load 150 to provide electrical energy to the load 150. The inverter 131 may be a hybrid inverter (Hybrid Inverter), which can provide the electrical energy output by the first power generation device 133 to the load 150, and can also provide the electrical energy output by the first power generation device 133 to the energy storage device 132. The first power generation device 133 may include a photovoltaic module, which is used to convert light energy (solar energy) into direct current.

[0070] It should be noted that the energy storage system may include multiple lines, each line is provided with a load 150, and each line may choose whether to provide an inverter energy storage device 130 as needed. Under the control of the control device 110, the inverter energy storage device 130 may only supply power to the load 150 on the same line, or may supply power to the load 150 on the same line and the load 150 on other lines at the same time. Figure 1 As shown, under the control of the control device 110, the power provided by the inverter energy storage device 130 of line 1 can be greater than the power required by the load 150 of line 1, so as to realize power supply for the loads 150 in line 1 and line 2 at the same time.

[0071] Optionally, the power supply system 140 may include but is not limited to a power grid or a second power generation device. The second power generation device can convert light energy and / or wind energy into electrical energy. Exemplarily, the load 150 may include but is not limited to household appliances and electronic devices, etc. The household appliances may include air conditioners, televisions, etc., and the electronic devices may include mobile phones, tablet computers, etc.

[0072] Exemplarily, the control device 110 is connected to the power distribution device 120 by wired communication, such as the control device 110 is connected to the control unit 122 of the power distribution device 120 by wired communication. Optionally, the control device 110 communicates with the power distribution device 120 via Ethernet, serial communication, etc. The control device 110 sends a first switching instruction to the power distribution device 120, so that the power distribution device 120 controls the grid-connected and off-grid switch 121 of the power distribution device 120 to perform a first switching action, such as the control unit 122 controls the grid-connected and off-grid switch 121 to perform a first switching action corresponding to the target grid-connected and off-grid mode according to the first switching instruction.

[0073] In some embodiments, the control device 110 is arranged near the power distribution equipment or on the wall of the building, and the control device 110 is wirelessly connected to the terminal device 160. In this embodiment, since the position of the control device 110 is fixed, by enabling the terminal device 160 to be wirelessly connected to the control device 110, it is convenient for the user to control the energy storage system and understand the information of the energy storage system. Optionally, the control device 110 and the terminal device 160 can be connected via Wi-Fi (Wireless Fidelity), Zigbee, Z-Wave (Zensys Wave), etc. Exemplarily, the control device 110 can receive a target switching instruction sent by the terminal device 160, so that the user can perform a target switching operation on the terminal device to achieve on-grid switching. Exemplarily, the terminal device can generate a target switching instruction in response to the target switching operation.

[0074] Exemplarily, the terminal device 160 may include but is not limited to a mobile phone, a PC (Personal Computer), a laptop computer, a tablet computer, etc.

[0075] In an embodiment of the present application, when the target on-grid and off-grid switching conditions are met, or when a target switching instruction sent by a terminal device is received, the control device first sends a standby instruction to each inverter energy storage device to stop each inverter energy storage device from receiving or outputting electric energy, and then sends a first switching instruction to the power distribution device, thereby avoiding the on-grid and off-grid switch action when the inverter energy storage device is performing charging and discharging operations, preventing the generation of reverse current, reducing the impact on the load caused by sudden changes in current or voltage, and avoiding triggering the protection mechanism, thereby improving the safety and stability of the energy storage system. After sending the first switching instruction to the power distribution device, the control device will control the inverter energy storage device to enter the target on-grid and off-grid mode, enabling the inverter energy storage device to output or receive electric energy again, avoiding signal mutations, and further improving the safety and stability of the system.

[0076] Please refer to Figure 2 , which shows a flow chart of a method for switching between on-grid and off-grid provided in an embodiment of the present application, which method can be applied to control equipment, such as EMS.

[0077] like Figure 2 As shown, the on-grid and off-grid switching method may include steps 202 to 206.

[0078] Step 202, in response to satisfying the target off-grid switching condition, or in the case of receiving a target switching instruction sent by a terminal device, sending a standby instruction to one or more inverter energy storage devices.

[0079] Among them, the target switching instruction is generated by the terminal device in response to the target switching operation, and the standby instruction is used to instruct the inverter energy storage device to enter the standby state. In the standby state, the inverter energy storage device does not perform charging and discharging operations. It should be noted that the target switching instruction may include a first switching instruction corresponding to the grid-connected mode, or a second switching instruction corresponding to the off-grid mode. The first switching instruction is used to indicate that the inverter energy storage device needs to work in the grid-connected mode, and the second switching instruction is used to indicate that the inverter energy storage device needs to work in the off-grid mode. The charging and discharging operation may include a charging operation and a discharging operation. The charging operation may refer to the operation of the inverter energy storage device receiving electric energy, and the discharging operation may refer to the operation of the inverter energy storage device outputting electric energy. In response to meeting the target grid-connected and off-grid switching conditions, the control device sends a standby instruction to each inverter energy storage device in the energy storage system. That is, if the energy storage system includes N inverter energy storage devices, the control device sends a standby instruction to the N inverter energy storage devices in response to meeting the target grid-connected and off-grid switching conditions, so that the N inverter energy storage devices enter the standby state. Wherein, N is an integer greater than or equal to 1. In the case where the energy storage system has multiple inverter energy storage devices, each inverter energy storage device can perform the same charging and discharging operation at the same time, or at least two inverter energy storage devices can perform different charging and discharging operations at the same time. When the same inverter energy storage device works in a grid-connected mode or an off-grid mode, the inverter energy storage device can perform a charging operation, a discharging operation, or switch between performing a charging operation and performing a discharging operation, which is not limited in the embodiments of the present application.

[0080] It should be noted that the target on-grid and off-grid switching conditions may include on-grid switching conditions corresponding to the on-grid mode, or off-grid switching conditions corresponding to the off-grid mode. When the on-grid switching conditions are met, it can be considered that the inverter energy storage device needs to work in the on-grid mode, and when the off-grid switching conditions are met, it can be considered that the inverter energy storage device needs to work in the off-grid mode. For the description of the on-grid mode and the off-grid mode, please refer to the above embodiments, which will not be repeated here.

[0081] For example, the control device can automatically detect whether the target on-grid and off-grid conditions are met. If the target on-grid and off-grid conditions are not met, the inverter energy storage device is maintained to work in the current on-grid and off-grid mode. If the conditions are met, a standby instruction is sent to one or more inverter energy storage devices. In this embodiment, by reasonably setting the target on-grid and off-grid conditions, the inverter energy storage device can work to meet the needs of the user, or match the power supply status of the power supply system, thereby improving the flexibility and intelligence of the energy storage system.

[0082] Step 204: Send a first switching instruction to the power distribution equipment.

[0083] Among them, the first switching instruction is used to instruct the distribution equipment to control the grid-connected and off-grid switch of the distribution equipment to perform the first switching action corresponding to the target grid-connected and off-grid mode. Among them, the first switching action may include a closing action corresponding to the grid-connected mode, or a disconnecting action corresponding to the off-grid mode. For the description of the closing action and the disconnecting action, please refer to the above embodiments and will not be repeated here. It should be noted that since the energy storage device will not output or receive electric energy to the outside in the standby state, the control device sends the first switching instruction to the distribution equipment after sending the standby instruction to the inverter energy storage device included in the energy storage system, which can avoid the reverse current generated by the grid-connected and off-grid switch action. At the same time, the phenomenon of sudden changes in current or voltage is reduced, the impact on the load is avoided, the power supply quality is improved, the protection mechanism is avoided from being triggered, and the power supply continuity of the load is ensured.

[0084] In some embodiments, the control device can send a first switching instruction to the power distribution device when the time from the current moment to the moment of sending a standby instruction to one or more inverter energy storage devices reaches the first waiting time. It should be noted that since it takes time for the control device to send a standby instruction to the inverter energy storage device and for the inverter energy storage device to respond to the receipt of the standby instruction and control the inverter energy storage device to be in a standby state, the control device waits for the first waiting time after sending the standby instruction to one or more inverter energy storage devices, and then sends the first switching instruction to the power distribution device, which can ensure that when all the inverter energy storage devices are in a standby state, the grid-connected and off-grid switches of the distribution device are controlled to perform the first switching action corresponding to the target grid-connected and off-grid mode, further ensuring the power supply quality of the energy storage system. It is understandable that the first waiting time can be set according to actual conditions, such as determined according to the interval between the control device sending a standby instruction to the inverter energy storage device and the inverter energy storage device being in a standby state, and this embodiment does not limit this.

[0085] Step 206: Control one or more inverter energy storage devices to operate in the target on-grid and off-grid mode.

[0086] It should be noted that the target on-grid and off-grid modes may include on-grid mode and off-grid mode. If the control device detects that the on-grid switching conditions are met, the on-grid and off-grid switch should be controlled to be in a closed state, and each inverter energy storage device should be controlled to work in the on-grid mode. If the control device detects that the off-grid switching conditions are met, the on-grid and off-grid switch should be controlled to be in a disconnected state, and each inverter energy storage device should be controlled to work in the off-grid mode. If the control device receives a first switching instruction sent by the terminal device, the on-grid and off-grid switch should be controlled to be in a closed state, and each inverter energy storage device should be controlled to work in the on-grid mode. If the control device receives a second switching instruction sent by the terminal device, the on-grid and off-grid switch should be controlled to be in a disconnected state, and each inverter energy storage device should be controlled to work in the off-grid mode. The control device can control the inverter energy storage device to be in a discharging state, a charging state, or a standby state. In the discharging state, the inverter energy storage device performs a discharging operation, and in the charging state, the inverter energy storage device performs a charging operation. In the standby state, the inverter energy storage device does not perform a charging operation or a discharging operation.

[0087] Optionally, when the inverter energy storage device operates in the grid-connected mode, the inverter energy storage device can operate synchronously with the power supply system, the inverter energy storage device can provide electrical energy to the load, or to the power supply system, and the inverter energy storage device can also obtain electrical energy from the power supply system and store the electrical energy.

[0088] Optionally, when the inverter energy storage device operates in an off-grid mode, the inverter energy storage device independently provides electrical energy to the load to keep the load working.

[0089] In the related art, when the inverter energy storage device works in the grid-connected mode, the inverter energy storage device needs to synchronize the amplitude and frequency of the output electrical signal with the amplitude and frequency of the electrical signal output by the power supply system (such as the power grid). When the inverter energy storage device works in the off-grid mode, the inverter energy storage device autonomously adjusts the amplitude and frequency of the output electrical signal. In this embodiment, after the control device sends the first switching instruction to the power distribution device, it controls the inverter energy storage device to work in the target grid-connected and off-grid mode, that is, after the grid-connected and off-grid switch is switched, the electrical energy output of the inverter energy storage device is realized, which can avoid sudden changes in the signal, while ensuring the synchronization of the electrical signals of the energy storage system, and improving the stability and safety of the energy storage system.

[0090] Exemplarily, the control device may be preset with a first control strategy corresponding to the grid-connected mode and a second control strategy corresponding to the off-grid mode. The first control strategy and the second control strategy may be set by a management personnel. When the target grid-connected and off-grid mode is the grid-connected mode, the control device controls the inverter energy storage device to work based on the first control strategy, and when the target grid-connected and off-grid mode is the off-grid mode, the control device controls the inverter energy storage device to work based on the second control strategy.

[0091] In some embodiments, in the grid-connected mode, the control device can control each inverter energy storage device to be in a standby state, and the loads connected to the energy storage system are all provided with power by the power supply system.

[0092] In other embodiments, the power supply system may include a power grid, and the first control strategy may include a first control sub-strategy corresponding to a high-price time period, and a second control sub-strategy corresponding to a low-price time period. In the grid-connected mode, the control device determines the target time period to which the current time period belongs, and controls the inverter energy storage device to work based on the control sub-strategy corresponding to the target time period. Among them, the first control strategy may include controlling at least one inverter energy storage device in the energy storage system to perform a discharge operation, so as to provide electric energy to the load connected to the energy storage system through the inverter energy storage device performing the discharge operation, and the second control strategy may include controlling at least one inverter energy storage device in the energy storage system to perform a charging operation, so as to provide electric energy to the inverter energy storage device performing the charging operation through the electric energy provided by the power supply system, and to provide electric energy to the load connected to the energy storage system through the power supply system, wherein the electricity price corresponding to the high-price time period is higher than the electricity price corresponding to the low-price time period. In this embodiment, in the low-price time period, the load is powered by the power supply system, and the inverter energy storage device is charged, and the electric energy stored in the inverter energy storage device is used to perform functions for the load in the high-price time period, which can effectively reduce the user's electricity cost.

[0093] In some embodiments, in the off-grid mode, one or more inverter energy storage devices may be controlled to perform a discharge operation according to the total working power of the loads connected to the energy storage system to provide electrical energy to the loads connected to the energy storage system. It should be noted that in the off-grid mode, the inverter energy storage device provides electrical energy to the loads alone, and the control device may determine the inverter energy storage device in the energy storage system that needs to perform a discharge operation according to the total working power of all loads connected to the energy storage system, and control the inverter energy storage device that needs to perform a discharge operation to perform a discharge operation to provide electrical energy to the loads connected to the energy storage system.

[0094] It should be noted that the control strategies provided in the above embodiments are taken as examples, and the control device can control the inverter energy storage device to work based on other control strategies, and is not limited to the methods provided above.

[0095] In an embodiment of the present application, when the target on-grid and off-grid switching conditions are met, or when a target switching instruction sent by a terminal device is received, the control device first sends a standby instruction to each inverter energy storage device to stop each inverter energy storage device from receiving or outputting electric energy, and then sends a first switching instruction to the power distribution device, thereby avoiding the on-grid and off-grid switch action when the inverter energy storage device is performing charging and discharging operations, preventing the generation of reverse current, reducing the impact on the load caused by sudden changes in current or voltage, and avoiding triggering the protection mechanism, thereby improving the safety and stability of the energy storage system. After sending the first switching instruction to the power distribution device, the control device will control the inverter energy storage device to enter the target on-grid and off-grid mode, enabling the inverter energy storage device to output or receive electric energy again, avoiding signal mutations, and further improving the safety and stability of the system.

[0096] In some embodiments, the terminal device can generate a first switching instruction corresponding to the grid-connected mode in response to a first switching operation corresponding to the grid-connected mode, and send the first switching instruction to the control device to put the grid-connected and off-grid switch in a closed state and the inverter energy storage device operates in the grid-connected mode.

[0097] Exemplarily, the terminal device may also generate a second switching instruction corresponding to the off-grid mode in response to a second switching operation corresponding to the off-grid mode, and send the second switching instruction to the control device to put the off-grid switch in a disconnected state and the inverter energy storage device operates in the off-grid mode.

[0098] In some embodiments, the first switching operation may include a single-click operation, a long-press operation, or a double-click operation of the user on the on-grid and off-grid control interface, and the second switching operation may include a single-click operation, a long-press operation, or a double-click operation of the user on the on-grid and off-grid control interface. The first switching operation and the second switching operation may also include other feasible inputs, which are not limited in the embodiments of the present application.

[0099] Please refer to Figure 3 , which shows a schematic diagram of an on-grid and off-grid control interface provided by an embodiment of the present application. The terminal device may include a display screen, and the terminal device may display the on-grid and off-grid control interface through the display screen. Figure 3As shown, the grid-connected and off-grid control interface 300 may include a grid-connected button control 310 and an off-grid button control 320. The target switching operation includes a single-click operation of the user on the grid-connected button control 310, or a single-click operation of the user on the off-grid button control 320. Exemplarily, the terminal device generates a first switching instruction corresponding to the grid-connected mode in response to a single-click operation on the grid-connected button control 310, and sends it to the control device. If the control device receives the first switching instruction, it sends a standby instruction to one or more inverter energy storage devices, and executes steps 204 to 206. In response to a single-click operation on the off-grid button control 320, the terminal device generates a second switching instruction corresponding to the off-grid mode, and sends it to the control device. When the control device receives the second switching instruction, it sends a standby instruction to one or more inverter energy storage devices, and executes steps 204 to 206.

[0100] In some embodiments, Figure 4 As shown, the terminal device may be installed with an on-grid and off-grid APP (Application, third-party application) 410. When the user triggers the on-grid and off-grid APP 410, the terminal device may display a device interface 420. The device interface 420 may include an on-grid and off-grid control 421. After the user triggers the on-grid and off-grid control 421, the on-grid and off-grid APP will automatically switch to the on-grid and off-grid control interface 300.

[0101] For example, Figure 4 As shown, the on-grid and off-grid control 421 can be an icon button. Using a switch icon to represent the on-grid and off-grid control control can save space and enhance visual aesthetics.

[0102] For example, Figure 4 As shown, the device interface 420 can also display information of one or more inverter energy storage devices, such as the charging and discharging status and online status of the inverter energy storage device, the line where the inverter energy storage device is located, the type of inverter energy storage device, etc. The information displayed on the device interface 420 can be set as needed, and this embodiment does not limit this.

[0103] In this embodiment, a grid-connected button control and an off-grid button control are displayed on the grid-connected and off-grid control interface. The user can control the inverter energy storage device to operate in the desired grid-connected or off-grid mode by operating the grid-connected button control or the off-grid button control (such as a single-click operation), thereby improving the convenience of user operation and reducing the probability of user operation errors.

[0104] In some embodiments, the target switching operation may further include a first determination operation, and the terminal device may output a first prompt message in response to the first switching operation, and generate a first switching instruction in response to the first determination operation for the first prompt message, and send it to the control device. Among them, the first prompt message is used to prompt the user to select whether to control the inverter energy storage device to work in the grid-connected mode. Exemplarily, the first determination operation may include a single-click operation, a long-press operation, or a double-click operation for the first prompt message. The user determines that the inverter energy storage device needs to be controlled to work in the grid-connected mode, and the first determination operation may be performed.

[0105] Exemplarily, the first prompt information may include a first text content, a first button control, and a second button control. The first text content is used to prompt whether to control the inverter energy storage device to operate in the grid-connected mode. The first button control corresponds to controlling the inverter energy storage device to operate in the grid-connected mode. The second button control corresponds to not controlling the inverter energy storage device to operate in the grid-connected mode. The first determination operation may include an operation to trigger the first button control. The terminal device may generate a first switching instruction in response to the operation to trigger the first button control and send it to the control device.

[0106] Figure 5 A schematic diagram of first prompt information displayed by a terminal device provided in an embodiment of the present application is shown. Figure 5 As shown, the first text content may be "Grid connection is about to begin, and the home grid will be out of power for a while. Are you ready?", the first button control 510 may be a confirmation button, and the second button control 520 may be a cancel button.

[0107] In some embodiments, the target switching operation may further include a second determination operation. The terminal device may output a second prompt message in response to the second switching operation, and generate a second switching instruction in response to the second determination operation for the second prompt message, and send it to the control device. The second prompt message is used to prompt the user to select whether to control the inverter energy storage device to work in off-grid mode. The second determination operation may include a single-click operation, a long-press operation, or a double-click operation for the second prompt message. If the user determines that the inverter energy storage device needs to be controlled to work in off-grid mode, the second determination operation may be performed.

[0108] Exemplarily, the second prompt information may include a second text content, a third button control and a fourth button control, the second text content is used to prompt whether to control the inverter energy storage device to operate in an off-grid mode, the third button control corresponds to controlling the inverter energy storage device to operate in an off-grid mode, and the fourth button control corresponds to not controlling the inverter energy storage device to operate in an off-grid mode, the second determination operation may include an operation to trigger the third button control, and the terminal device may generate a second switching instruction in response to the operation to trigger the third button control, and send it to the control device.

[0109] Figure 6 A schematic diagram of second prompt information displayed by a terminal device provided in an embodiment of the present application is shown. Figure 6 As shown, the second text content may be "You are about to go off the grid, and the home grid will be out of power for a while. Are you ready?", the third button control 610 may be a confirmation button, and the fourth button control 620 may be a cancel button.

[0110] In this embodiment, when the terminal device detects a target switching operation, it will display a corresponding prompt message. Only when the user performs a confirmation operation corresponding to the prompt message will the target switching instruction be sent to the control device, thereby avoiding user misoperation and ensuring the reliability of on-grid and off-grid switching.

[0111] In the related art, the inverter energy storage device controls its operation in the grid-connected mode or the off-grid mode according to whether the power grid is in a fault state. The inverter energy storage device does not need to communicate with the terminal device, so the processing and communication performance requirements of the inverter energy storage device are relatively low. In this embodiment, the control device communicates with the terminal device and the inverter energy storage device respectively, and receives the target switching instruction sent by the terminal device through the control device to control the inverter energy storage device to operate in different grid-connected and off-grid modes. There is no need to add complex processing and communication functions to the inverter energy storage device, that is, it can achieve compatible manual switching mode (user manual control) while maintaining the current processing and communication performance of the inverter energy storage device, thereby improving the human-computer interaction performance and practicality of the energy storage system.

[0112] The above embodiment provides a manual switching solution, and the following embodiment will provide an automatic switching solution.

[0113] In some embodiments, the control device may detect the supply voltage input by the power supply system. If it is detected that the supply voltage does not belong to the voltage range corresponding to the grid-connected or off-grid mode in which one or more inverter energy storage devices are currently located, it is determined that the target grid-connected or off-grid switching condition is met. It should be noted that the supply voltage input by the power supply system may refer to the voltage received by the energy storage system from the power supply system, or the voltage provided by the power supply system to the energy storage system. The voltage range corresponding to the grid-connected mode refers to the voltage range corresponding to the supply voltage input by the power supply system when the power supply system is in a normal state, and the voltage range corresponding to the off-grid mode refers to the voltage range corresponding to the supply voltage input by the power supply system when the power supply system is in a fault state. Exemplarily, the normal state may refer to a state in which the operating parameters of the power supply system remain within a set safety range and can provide high-quality electric energy. The fault state may refer to a state in which the operating parameters of the power supply system deviate from the set normal range, the quality of the electric energy provided is poor, or even no electric energy can be provided.

[0114] Exemplarily, when the grid-connected or off-grid mode currently in which the inverter energy storage device in the energy storage system is in the off-grid mode, if it is detected that the power supply voltage does not belong to the voltage range corresponding to the off-grid mode, it is determined that the grid-connected switching condition is met.

[0115] Exemplarily, when the on-grid and off-grid mode currently in which the inverter energy storage device in the energy storage system is in the on-grid mode, if it is detected that the power supply voltage does not belong to the voltage range corresponding to the on-grid mode, it is determined that the off-grid switching condition is met.

[0116] Exemplarily, the voltage range corresponding to the target on-grid and off-grid mode can be determined according to the rated voltage and tolerance range of the power supply system. The tolerance range is used to indicate the tolerable range of variation. Exemplarily, the voltage range corresponding to the on-grid mode is (aa*b) to (a+a*b), and the voltage range corresponding to the off-grid mode includes less than (aa*b) or greater than (aa*b). Where a is the rated voltage, b is the tolerance factor, and optionally, the range corresponding to b includes 9% to 11%. Optionally, b may be 9%, 10% or 11%, etc.

[0117] Taking the power supply system as a power grid as an example, the rated voltage is 220V, the tolerance coefficient is 10%, the voltage range corresponding to the grid-connected mode includes 198V (volts) to 242V, and the voltage range corresponding to the off-grid mode includes less than 198V, or greater than 242V.

[0118] The supply voltage input to the power supply system is affected by many factors, such as the number of loads, so that when the power supply system is in a normal state, the supply voltage may deviate from the rated voltage. In this embodiment, the target voltage range based on the rated voltage and the tolerance range can make the on-grid and off-grid switching method have higher anti-interference ability and ensure the reliability of on-grid and off-grid switching.

[0119] In some embodiments, the voltage range corresponding to the target on-grid and off-grid mode can be determined according to the rated voltage and hysteresis range of the power supply system. Among them, the hysteresis range can be used to prevent frequent on-grid and off-grid mode switching actions, and the hysteresis range is generally greater than the tolerance range. Exemplarily, the voltage range corresponding to the on-grid mode includes (aa*c1) to (a+a*c2), and the voltage range corresponding to the off-grid mode includes less than (aa*c1) or greater than (aa*c2). Among them, a is the rated voltage, c1 is the first hysteresis coefficient, and c2 is the second hysteresis coefficient. Optionally, the range corresponding to c1 may include 15% to 16%. Optionally, c1 may be 15%, 15%, 16%, etc. Optionally, the range corresponding to c2 may include 19% to 21%. Optionally, c2 may be 19%, 20% or 21%, etc.

[0120] Taking the power supply system as a grid as an example, the rated voltage is 220V, the first hysteresis coefficient is 15.9%, the second hysteresis coefficient is 20%, the voltage range corresponding to the grid-connected mode includes 185V to 264V, and the voltage range corresponding to the off-grid mode is less than 185V or greater than 264V.

[0121] It can be understood that the first hysteresis coefficient and the second hysteresis coefficient may be unequal or equal, and may be set according to actual needs, and this embodiment does not make any specific limitation to this.

[0122] In this embodiment, the voltage range corresponding to the target on-grid and off-grid mode is determined by taking the tolerance range into consideration, so that frequent operation of on-grid and off-grid switches and inverter energy storage devices can be avoided, thereby improving the stability of the energy storage system.

[0123] In some embodiments, please refer to Figure 7 The control device 710 can be connected to the first position A to detect the supply voltage input by the power supply system 720. The first position A is the position of the electrical connection channel between the access point of the power supply system 720 and the power distribution equipment 730, that is, the control device 710 can detect the supply voltage input by the power supply system 720.

[0124] In some embodiments, if the power supply voltage does not belong to the on-grid or off-grid mode currently in which one or more inverter energy storage devices are currently located, and the duration of the corresponding voltage range is greater than the preset duration, it is determined that the target on-grid or off-grid switching condition is met. It should be noted that the on-grid and off-grid modes currently in which the inverter energy storage devices of the energy storage system are located are the same, and the first duration threshold can be set according to actual needs. The range of the first duration threshold may include greater than or equal to 3 seconds, and the first duration threshold may be 3 seconds, 4 seconds or 5 seconds. In this embodiment, the power supply voltage does not belong to the duration of the voltage range corresponding to the on-grid and off-grid mode currently in which the inverter energy storage devices of the energy storage system are located. After exceeding the first duration threshold, switching can reduce misjudgment caused by instantaneous fluctuations in the power supply voltage. Switching is performed only when the power supply voltage is ensured to be continuously stable, thereby avoiding unnecessary switching, improving power supply quality, and preventing frequent power outages or instantaneous power failures of the load.

[0125] In some embodiments, the control device determines whether the power supply voltage belongs to the voltage range corresponding to the grid-connected mode and whether the grid-connected and off-grid switch is in the disconnected state. If it is determined that the power supply voltage belongs to the voltage range corresponding to the grid-connected mode and the grid-connected and off-grid switch is in the disconnected state, it is determined that the power supply voltage is not within the voltage range corresponding to the off-grid mode, and it can be determined that the grid-connected switching conditions are met.

[0126] In some embodiments, the control device determines whether the supply voltage belongs to the voltage range corresponding to the off-grid mode, and whether the state of the on-grid and off-grid switch is in a closed state. If it is determined that the supply voltage belongs to the voltage range corresponding to the off-grid mode, and the on-grid and off-grid switch is in a closed state, it is determined that the supply voltage is detected not to belong to the voltage range corresponding to the on-grid mode, and it can be determined that the off-grid switching condition is met.

[0127] In this embodiment, when it is determined that the power supply voltage does not belong to the voltage range corresponding to the current on-grid and off-grid mode of one or more inverter energy storage devices, the control device can automatically determine whether the target on-grid and off-grid switching conditions are met, that is, determine that the inverter energy storage device needs to switch from the current on-grid and off-grid mode to another on-grid and off-grid mode, so that the operation of the inverter energy storage device matches the power supply voltage of the power supply system, thereby ensuring the effectiveness of the on-grid and off-grid switching.

[0128] In some embodiments, if the control device receives a target switching instruction sent by the terminal device, it determines that the target on-grid and off-grid switching conditions are met, and if it is detected that the power supply voltage input by the power supply system does not belong to the voltage range corresponding to the on-grid and off-grid mode currently in which one or more inverter energy storage devices are located, it is determined that the target on-grid and off-grid switching conditions are met. In this embodiment, the control device can determine whether the target on-grid and off-grid switching conditions are met based on whether the target switching instruction is received and the detected power supply voltage, providing multiple ways to trigger on-grid and off-grid mode switching, thereby improving the flexibility of the energy storage system.

[0129] In some embodiments, in the automatic switching mode, if a target switching instruction sent by a terminal device is received, the target switching instruction is not responded to. In this embodiment, in the automatic switching mode, the control device automatically executes and switches off the grid according to the set automatic trigger condition (the range of the power supply voltage), that is, executes steps 202 to 206, avoiding unnecessary switching or operation caused by human intervention, thereby improving the power supply stability of the energy storage system.

[0130] In some embodiments, in the manual switching mode, the control device does not detect whether the power supply voltage input by the power supply system meets the voltage range corresponding to the target on-grid and off-grid mode. In this embodiment, in the manual switching mode, the control device is triggered to perform on-grid and off-grid switching only when the user performs the corresponding operation, that is, to perform steps 202 to 206, thereby reducing the impact of misjudgment caused by power supply voltage fluctuations on the energy storage system, and meeting the user's specific needs for the energy storage system, such as testing.

[0131] In some embodiments, in response to a target selection instruction sent by a terminal device, a target operation mode is determined. The target operation mode includes a manual switching mode or an automatic switching mode. It should be noted that the target selection instruction includes a first selection instruction corresponding to the manual switching mode, or a second selection instruction corresponding to the automatic switching mode. The control device determines that the switching mode is the manual switching mode after receiving the first selection instruction sent by the terminal device, and determines that the switching mode is the automatic switching mode after receiving the second selection instruction sent by the terminal device.

[0132] In some embodiments, the terminal device may generate a target selection instruction in response to the target selection operation and send the target selection instruction to the control device. It should be noted that the target selection operation includes a first selection operation corresponding to the manual switching mode and a second selection operation corresponding to the automatic switching mode. For example, Figure 8 As shown, the on-grid and off-grid control interface 800 may further include a mode switching control 810, and the type of the mode switching control 810 may be a toggle switch control. In this embodiment, by setting the on-grid button control 820, the off-grid button control 830 and the mode switching control 810 on the same interface, that is, the on-grid and off-grid control interface 800 includes the on-grid button control 820, the off-grid button control 830 and the mode switching control 810, it is convenient for users to operate and reduce the difficulty of user operation.

[0133] In this embodiment, the control device can receive a target selection instruction from the terminal device. The user can switch the on-grid and off-grid trigger conditions by performing a target selection operation on the terminal device. By clearly distinguishing between the manual switching mode and the automatic switching mode, on-grid and off-grid switching can be performed more reliably and unnecessary intervention can be reduced.

[0134] In some embodiments, the control device may also determine status display information and send the status display information to the terminal device so that the terminal device displays the status display information. The status display information may include the on-grid and off-grid mode currently in which one or more inverter energy storage devices are located, and / or the working state of the power supply system. It should be noted that the working state includes a normal state and a fault state. For the description of the normal state and the fault state, please refer to the above embodiments and will not be repeated here.

[0135] Exemplarily, the control device may send status display information to the terminal device only when the on-grid or off-grid mode of one or more inverter energy storage devices currently in changes, and / or when the working state of the power supply system changes, so that the status display information output by the terminal device matches the energy storage system and the power supply system, thereby reducing the interaction between the terminal device and the control device and reducing the resources occupied by communication. In another example, the control device may also send status display information to the terminal device according to a preset period, which is not specifically limited in this embodiment.

[0136] In some embodiments, if the control device determines that the detected power supply voltage belongs to the voltage range corresponding to the grid-connected mode, the power supply system is determined to be in a normal state. If the control device determines that the detected power supply voltage belongs to the voltage range corresponding to the off-grid mode, the power supply system is determined to be in a fault state.

[0137] In some embodiments, when the control device controls one or more inverter energy storage devices to work in the grid-connected mode, it can be determined that the grid-connected and off-grid mode currently in which the one or more inverter energy storage devices are located is the grid-connected mode. When the control device controls one or more inverter energy storage devices to work in the off-grid mode, it can be determined that the grid-connected and off-grid mode currently in which the one or more inverter energy storage devices are located is the off-grid mode.

[0138] For example, please continue to refer to Figure 8 , the grid-connected and off-grid control interface 800 may also include a first display control 840 and a second display control 850. The first display control 840 is used to display the grid-connected and off-grid modes currently in which one or more inverter energy storage devices are located. The second display control 850 is used to display the working status of the power supply system. In this embodiment, the first display control 840, the second display control 850, the grid-connected button control 820 and the off-grid button control 830 are set on the same interface, so that the user can select the desired grid-connected and off-grid mode by triggering the grid-connected button control 820 or the off-grid button control 830 after understanding the current grid-connected and off-grid modes of the inverter energy storage device and the working status of the power supply system, thereby reducing the phenomenon of user misoperation.

[0139] Exemplarily, when the grid-connected or off-grid mode currently in which one or more inverter energy storage devices is located is the off-grid mode, the first display control 840 displays "off-grid"; and when the grid-connected or off-grid mode currently in which one or more inverter energy storage devices is located is the grid-connected mode, the first display control 840 displays "grid-connected".

[0140] Exemplarily, when the working state of the power supply system is normal, the second display control 850 displays "yes", indicating that the power supply system can provide electrical energy. When the working state of the power supply system is a fault state, the second display control 850 displays "no", indicating that the power supply system cannot provide electrical energy.

[0141] In this embodiment, the control device can monitor the grid-connected and off-grid modes of each inverter energy storage device and the working status (power supply status) of the power supply system in real time. According to the monitoring results, the control device generates status display information and sends it to the terminal device. After receiving the status display information, the terminal device displays the information in the first display control and the second display control of the grid-connected and off-grid switching interface to display the grid-connected and off-grid modes of the inverter energy storage device and the working status of the power supply system, so that the user can control the grid-connected and off-grid modes more intuitively.

[0142] Please refer to Fig. 9 , which shows a flow chart of another on-grid and off-grid switching method provided in an embodiment of the present application, and the on-grid and off-grid switching method can be applied to a control device.

[0143] like Fig. 9 As shown, the on-grid and off-grid switching method may include steps 902 to 912.

[0144] Step 902, in response to satisfying the target off-grid switching condition, or in the case of receiving a target switching instruction sent by a terminal device, sending a standby instruction to one or more inverter energy storage devices.

[0145] It should be noted that the control device sends a standby instruction to the inverter energy storage device included in the energy storage system in response to meeting the target and off-grid switching conditions, or in the case of receiving a target switching instruction sent by the terminal device.

[0146] Step 904: Send a first switching instruction to the power distribution equipment.

[0147] For the description of step 902 to step 904, please refer to the above embodiment, which will not be repeated here.

[0148] Step 906, judging whether the inverter energy storage device has successfully switched to the target off-grid mode according to the first input voltage of the load, if not, executing steps 908 to 910, and if yes, executing step 912.

[0149] It should be noted that the first input voltage of the load may refer to the input voltage of each load in the energy storage system. The inverter energy storage device successfully switches to the target on-grid and off-grid mode, which can be understood as the energy storage system already has the conditions for the inverter energy storage device to stably operate in the target on-grid and off-grid mode. For example, when the inverter energy storage device successfully switches to the target on-grid and off-grid mode, the inverter energy storage device operates in the target on-grid and off-grid mode, and the energy storage system can smoothly provide electricity to the power supply system or the load. The inverter energy storage device does not successfully switch to the target on-grid and off-grid mode, which can be understood as the energy storage system does not have the conditions for the inverter energy storage device to stably operate in the target on-grid and off-grid mode. For example, if the on-grid and off-grid switch is not successfully closed, the power supply system cannot provide electrical energy to the load at this time, and the inverter energy storage system may not be able to provide enough electrical energy to the load even if it operates in the on-grid mode.

[0150] It should be noted that when the target on-grid and off-grid switching condition is the on-grid switching condition, after the control device sends the first switching instruction to the power distribution device, the on-grid and off-grid switch should be in a closed state. Since the inverter energy storage device is in a standby state, the first input voltage of the load can be understood as the voltage provided by the power supply system to the load. At this time, the first input voltage of the load belongs to the voltage range corresponding to the on-grid mode. When the target on-grid and off-grid switching condition is the off-grid switching condition, after the control device sends the first switching instruction to the power distribution device, the on-grid and off-grid switch should be in a disconnected state. Since the inverter energy storage device is in a standby state, the load should not receive electric energy, and the first input voltage of the load should belong to the voltage range corresponding to the off-grid mode.

[0151] In some embodiments, if the first input voltage of the load belongs to the voltage range corresponding to the target on-grid and off-grid mode, it is determined that the inverter energy storage device has successfully switched to the target on-grid and off-grid mode. If the first input voltage of the load does not belong to the voltage range corresponding to the target on-grid and off-grid mode, it is determined that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode.

[0152] In some embodiments, if the duration of the first input voltage of the load belonging to the voltage range corresponding to the target on-grid and off-grid mode is greater than the second duration threshold, it is determined that the inverter energy storage device is successfully switched to the target on-grid and off-grid mode. Exemplarily, the range of the second duration threshold may include 2 seconds to 4 seconds. Optionally, the second duration threshold may be 2 seconds, 3 seconds or 4 seconds, etc.

[0153] In this embodiment, by judging whether the first input voltage of the load within the second time threshold belongs to the voltage range corresponding to the target on-grid and off-grid mode, and whether the voltage range corresponding to the target on-grid and off-grid mode is greater than the second time threshold, it is determined whether the inverter energy storage device has successfully switched to the target on-grid and off-grid mode. This can avoid misjudgment caused by short-term fluctuations and improve the reliability of the inverter energy storage device during the switching process between on-grid and off-grid modes.

[0154] In some embodiments, the control device may determine whether the inverter energy storage device has successfully switched to the target on-grid and off-grid mode according to the first input voltage of the load and the switch state of the on-grid and off-grid switch. It should be noted that the switch state of the on-grid and off-grid switch includes a closed state and an open state. The switch state of the on-grid and off-grid switch can help the control device confirm the physical connection between the power supply system and the load, and ensure that the device is electrically in the correct working state. Exemplarily, the power distribution device may send switch state information to the control device, and the switch state information is used to indicate the switch state of the on-grid and off-grid switch.

[0155] Exemplarily, when the target on-grid and off-grid switching condition is the grid-connected switching condition, if the first input voltage of the load belongs to the voltage range corresponding to the grid-connected mode, and the switching state of the on-grid and off-grid switch is in a closed state, it is determined that the inverter energy storage device has successfully switched to the grid-connected mode.

[0156] Exemplarily, when the target on-grid and off-grid switching condition is the off-grid switching condition, if the first input voltage of the load belongs to the voltage range corresponding to the off-grid mode, and the switching state of the on-grid and off-grid switch is in the disconnected state, it is determined that the inverter energy storage device has successfully switched to the off-grid mode.

[0157] In some embodiments, please refer to Figure 7 , the control device 710 can be connected to the second position B to detect the input voltage of the load, the first position B is the position of the electrical connection channel between the power distribution device 730 and the load, and the control device 710 can detect the input voltage of the load. In this embodiment, the control device detects the input voltage of any load connected to the energy storage system, and the voltage of the first position B is consistent with the input voltage of each load.

[0158] In this embodiment, the control device comprehensively considers the first input voltage of the load and the switching state of the on-grid and off-grid switch, which can effectively avoid misjudgment caused by fluctuations or abnormalities of a single factor, thereby improving the accuracy of judgment and the stability of the energy storage system. At the same time, it also avoids the problem of load power supply interruption caused by unsuccessful switching.

[0159] Step 908: Send a second switching instruction to the power distribution equipment.

[0160] Among them, the second switching module is used to instruct the power distribution equipment to control the grid-connected and off-grid switch of the power distribution equipment to perform a second switching action, and the second switching action is different from the first switching action. It should be noted that the second switching instruction is used to instruct the power distribution equipment to control the grid-connected and off-grid switch to perform an action opposite to the first switching action. For example, when the first switching instruction is used to instruct the power distribution equipment to control the grid-connected and off-grid switch of the power distribution equipment to perform a closing action, the second switching instruction is used to instruct the power distribution equipment to control the grid-connected and off-grid switch of the power distribution equipment to perform a disconnecting action. When the first switching instruction is used to instruct the power distribution equipment to control the grid-connected and off-grid switch of the power distribution equipment to perform a disconnecting action, the second switching instruction is used to instruct the power distribution equipment to control the grid-connected and off-grid switch of the power distribution equipment to perform a closing action. That is, if the first switching action is a closing action, the second switching action may be a disconnecting action. If the first switching action is a disconnecting action, the second switching action may be a closing action.

[0161] Step 910, determining whether the time from the current moment to the moment of sending the second switching instruction to the power distribution device reaches a preset time, if so, returning to step 904, if not, continuing to step 910.

[0162] It should be noted that it takes time for the control device to send the second switching instruction to the power distribution device and for the on-grid switch to perform the second switching action. By sending the first switching instruction to the power distribution device only when the interval between the current moment and the moment when the control device sends the second switching instruction to the power distribution device reaches the preset time, the stability and safety of the on-grid switch switching can be ensured. It is understandable that the preset time can be set according to actual needs. Exemplarily, the range of the preset time may include 0.8 seconds to 1.2 seconds. Optionally, the preset time may be 0.8 seconds, 0.9 seconds, 1 second, 1.1 seconds or 1.2 seconds, etc.

[0163] In some embodiments, in the manual switching mode, if the inverter energy storage device still fails to successfully switch to the target on-grid and off-grid mode after the number of re-executions of step 904 reaches a preset number of times, a failure prompt message is sent to the terminal device, and the failure prompt message is output through the terminal device. Among them, the failure prompt message is used to indicate that the control of one or more inverter energy storage systems to operate in the target on-grid and off-grid mode has failed. Exemplarily, the failure prompt message may be a display message or a voice message. It should be noted that in the manual switching mode, it is controlled by the user, so in the event of a switching failure, a failure prompt message is output through the terminal device, and the switching failure is promptly fed back to the user to improve the user experience. Exemplarily, the preset number of times may include 3 to 5 times. Optionally, the preset number of times may be 3 times, 4 times or 5 times.

[0164] In some embodiments, the failure prompt information may include first failure information corresponding to the grid-connected mode and second failure information corresponding to the off-grid mode, wherein the first failure information is used to prompt that the control of one or more inverter energy storage systems to work in the grid-connected mode has failed, that is, the control of the inverter energy storage system included in the energy storage system has failed to work in the grid-connected mode. The second failure information is used to prompt that the control of one or more inverter energy storage systems to work in the off-grid mode has failed, that is, the control of the inverter energy storage system included in the energy storage system has failed to work in the off-grid mode.

[0165] For example, Fig.10 A schematic diagram of the first failure prompt information is shown. The terminal device may display the first failure information in a pop-up window. The first failure prompt information may include the text content of "Grid connection failed, please check the home / family circuit and power distribution equipment before trying to disconnect from the grid."

[0166] For example, Fig.11 A schematic diagram of the second failure prompt information is shown. The terminal device may display the second failure information in a pop-up window. The first failure prompt information may include the text content of "off-grid failure, please check the home / family circuit and power distribution equipment before trying to connect to the grid".

[0167] In some embodiments, in the case of automatic switching mode, if the number of executions of step 908 is greater than the preset number of times, the inverter energy storage device still fails to successfully switch to the target and off-grid mode, then wait for the third time threshold, and when the waiting time reaches the third time threshold, re-execute step 902. It should be noted that the preset number of times and the third time threshold can be set according to actual needs. Exemplarily, the preset number of times may include 3 to 5 times. Optionally, the preset number of times may be 3 times, 4 times or 5 times. Exemplarily, the range of the third time threshold may include 8 minutes to 12 minutes. Optionally, the third time threshold may be 8 minutes, 10 minutes or 12 minutes.

[0168] In this embodiment, by setting a preset number of times, if the number of attempts to switch exceeds the preset number and still fails, the control device will wait for the third time threshold, thereby avoiding infinite repetition and excessive consumption of resources. At the same time, by waiting for the third time threshold and then retrying the switch, the energy storage system can have a reasonable recovery and buffer time, which helps to improve the success rate and stability of the switch.

[0169] Step 912, controlling one or more inverter energy storage devices to operate in a target on-grid and off-grid mode.

[0170] When it is determined that the inverter energy storage device has successfully switched to the target on-grid and off-grid mode according to the first input voltage received by the load, one or more inverter energy storage devices are controlled to operate in the target on-grid and off-grid mode. For the description of step 912, please refer to the above embodiment, which will not be repeated here.

[0171] In this embodiment, after sending the first switching instruction to the distribution equipment, the control device will determine whether the inverter energy storage device has successfully switched to the target on-grid and off-grid mode based on the first input voltage received by the load, and if it fails to successfully switch to the target on-grid and off-grid mode, it will send a second switching instruction to the distribution equipment to restore the original state of the energy storage system, and then send the first switching instruction to the on-grid and off-grid switching module to re-try whether it can successfully switch to the target on-grid and off-grid mode, thereby ensuring the reliability and stability of on-grid and off-grid switching.

[0172] Please refer to Fig.12 , which shows a flow chart of another on-grid and off-grid switching method provided in an embodiment of the present application. The method can be applied to a control device. In this embodiment, the target on-grid and off-grid mode is a on-grid mode.

[0173] like Fig.12 As shown, the method may include steps 1202 to 1208.

[0174] Step 1202, in response to meeting the target off-grid switching condition, or in the case of receiving a target switching instruction sent by a terminal device, sending a standby instruction to one or more inverter energy storage devices.

[0175] Please refer to the above embodiment for the description of step 1202, which will not be repeated here.

[0176] Step 1204, determining whether the second input voltage of the load is within the preset power failure range. If yes, executing step 1206, if no, continuing to execute step 1202.

[0177] It should be noted that the second input voltage of the load may refer to the input voltage of each load in the energy storage system, and the second input voltage of the load may refer to the voltage at the second position. Before sending the first switching instruction to the power distribution equipment, the grid-connected and off-grid switch of the power distribution equipment is in a disconnected state, that is, the inverter energy storage device in the energy storage system provides electrical energy to the load. In this embodiment, the second input voltage received by the load may refer to the voltage output by one or more inverter energy storage devices. The preset power outage range can be set according to actual needs. The preset power outage range can be used to measure whether each inverter energy storage device in the energy storage system has no output electrical energy. If the second input voltage belongs to the preset power outage range, it can be considered that each inverter energy storage device in the energy storage system has no output electrical energy. If the second input voltage does not belong to the preset power outage range, there may be an inverter energy storage device that outputs electrical energy in the energy storage system. If the second input voltage received by the load does not fall within the preset power outage range, it may be because the inverter energy storage device has not yet entered the standby state. Therefore, the process can return to step 1202 until it is determined that the second input voltage of the load falls within the preset power outage range, and then the first switching instruction is sent to the power distribution equipment to ensure signal synchronization and improve the stability and reliability of on-grid and off-grid switching.

[0178] Exemplarily, the preset power outage range is less than the first voltage threshold. In some embodiments, the preset power outage range is consistent with the voltage range corresponding to the off-grid mode.

[0179] In some embodiments, it is determined whether the duration of the second input voltage of the load belonging to the preset power outage range reaches the fourth duration threshold. If not, return to step 1204, and if so, execute step 1206. Among them, the fourth duration threshold can be set according to actual needs. Exemplarily, the range of the fourth duration threshold may include 2.5 seconds to 3.5 seconds. Optionally, the fourth duration threshold may be 2.5 seconds, 3 seconds or 3.5 seconds, etc. Understandably, the fourth duration threshold may be fixed or changed according to actual conditions. In this embodiment, by determining whether the second input voltage within the fourth duration threshold belongs to the preset power outage range, it is determined whether the inverter energy storage device sends the first switching instruction to the distribution device. It can be ensured that the inverter energy storage devices included in the energy storage system are in a standby state before sending the first switching instruction to the distribution device, avoiding misjudgment caused by short-term fluctuations, and improving the reliability of the inverter energy storage device in the switching process between the grid-connected mode and the off-grid mode.

[0180] Step 1206: Send a first switching instruction to the power distribution equipment.

[0181] Step 1208, controlling one or more inverter energy storage devices to operate in a target on-grid and off-grid mode.

[0182] For the description of step 1206 to step 1208, please refer to the above embodiment, which will not be repeated here.

[0183] In this embodiment, the first switching instruction is sent to the power distribution equipment only when it is determined that the second input voltage of the load falls within the preset power outage range. This can avoid sudden changes in voltage and current, as well as problems with signal asynchrony, improve the reliability of on-grid and off-grid switching, and improve the continuity of load power supply.

[0184] In some embodiments, the inverter energy storage device may be manually controlled to be in different on-grid and off-grid modes, or the inverter energy storage device may be automatically controlled to be in different on-grid and off-grid modes.

[0185] Please refer to Fig.13 , which shows a schematic diagram of a process of manually switching to a grid-connected mode provided in an embodiment of the present application, wherein the process is applied to an EMS, and the power supply system is a power grid.

[0186] like Fig.13 As shown, the process may include steps 1302 to 1318.

[0187] Step 1302: In response to receiving a first switching instruction sent by a terminal device, a standby instruction is sent to one or more inverter energy storage devices.

[0188] Among them, the standby instruction is used to instruct each inverter energy storage device to enter the standby state. In the standby state, the inverter energy storage device does not perform charging and discharging operations. One or more inverter energy storage devices may refer to the inverter energy storage devices in the energy storage system. If the energy storage system only includes one inverter energy storage device, the EMS sends a standby instruction to the inverter energy storage device. If the energy storage system includes multiple inverter energy storage devices, the EMS sends a standby instruction to all of the multiple inverter energy storage devices. The EMS sends a standby instruction to one or more inverter energy storage devices to stop all inverter energy storage devices from performing charging and discharging operations.

[0189] Step 1304, determine whether the duration of the second input voltage of the load within the preset power outage range reaches a fourth duration threshold, if so, execute step 1306, if not, re-execute step 1304.

[0190] It should be noted that it takes time for the EMS to send a standby command and for the inverter energy storage device to enter the standby state. After the EMS sends a standby command to one or more inverter energy storage devices, it determines whether the duration of the second input voltage received by the load within the preset power outage range reaches the fourth duration threshold. If the duration of the second input voltage received by the load within the preset power outage range reaches the fourth duration threshold, it can be determined that the inverter energy storage devices included in the energy storage system have no output power. At this time, the distribution equipment is controlled and the off-grid switch is closed to avoid affecting the power grid.

[0191] Optionally, the preset power outage range includes less than 185V, or greater than 264V, and the fourth duration threshold may be greater than or equal to 3 seconds. If the duration of the second input voltage received by the load that falls within the preset power outage range reaches the fourth duration threshold, it can be considered that the energy storage system is powered off.

[0192] Step 1306, control the power distribution equipment to control the off-grid switch to close.

[0193] Step 1308, determine whether the on-grid and off-grid switch is in a closed state, if so, execute step 1310, if not, execute step 1314.

[0194] Step 1310 , determining whether the duration of the first input voltage of the load belonging to the voltage range corresponding to the grid-connected mode reaches a second duration threshold, if so, executing step 1312 , if not, executing step 1314 .

[0195] Optionally, the voltage range corresponding to the grid-connected mode includes 185V to 264V, and the second time threshold may be greater than or equal to 3 seconds.

[0196] Step 1312, controlling one or more inverter energy storage devices to operate in a grid-connected mode.

[0197] Step 1314, control the power distribution equipment to control the off-grid switch to perform the disconnection action, and determine whether the number of times the power distribution equipment controls the off-grid switch to perform the disconnection action is greater than the preset number. If so, execute step 1316, if not, execute step 1318, and return to execute step 1306.

[0198] Optionally, the preset number may be 3.

[0199] Step 1316, output the first failure prompt information.

[0200] Step 1318, wait for a preset time period.

[0201] Optionally, the preset duration is greater than or equal to 1 second.

[0202] Please refer to Fig.14 , which shows a schematic diagram of a process of manually switching to an off-grid mode provided in an embodiment of the present application, wherein the process is applied to an EMS, and the power supply system is a power grid.

[0203] like Fig.14 As shown, the process may include steps 1402 to 1416.

[0204] Step 1402: In response to receiving a second switching instruction sent by a terminal device, a standby instruction is sent to one or more inverter energy storage devices.

[0205] The standby instruction is used to instruct each inverter energy storage device to enter a standby state. In the standby state, the inverter energy storage device does not perform charging and discharging operations. One or more inverter energy storage devices may refer to the inverter energy storage devices in the energy storage system. If the energy storage system includes only one inverter energy storage device, the EMS sends a standby instruction to the inverter energy storage device. If the energy storage system includes multiple inverter energy storage devices, the EMS sends a standby instruction to all of the multiple inverter energy storage devices.

[0206] Step 1404, control the power distribution equipment to control the off-grid switch to perform a disconnection action.

[0207] Step 1406, determine whether the on-grid and off-grid switch is in the off state, if so, execute step 1408, if not, execute step 1412.

[0208] Step 1408, determining whether the duration of the first input voltage of the load belonging to the voltage range corresponding to the off-grid mode reaches a second duration threshold, if so, executing step 1410, if not, executing step 1412.

[0209] Optionally, the voltage range corresponding to the off-grid mode includes less than 185V, or greater than 264V, and the second time threshold may be greater than or equal to 3 seconds.

[0210] Step 1410, controlling one or more inverter energy storage devices to operate in an off-grid mode.

[0211] Step 1412, control the power distribution equipment to control the off-grid switch to close, and determine whether the number of times the power distribution equipment controls the off-grid switch to close is greater than the preset number. If so, execute step 1414, if not, execute step 1416, and return to execute step 1404.

[0212] Optionally, the preset number of times is 3.

[0213] Step 1414, output a second failure prompt message.

[0214] Step 1416, wait for a preset time period.

[0215] Optionally, the preset duration is greater than or equal to 1 second.

[0216] Please refer to Fig.15 , which shows a schematic diagram of a process of automatically switching to a grid-connected mode provided in an embodiment of the present application, wherein the process is applied to an EMS, and the power supply system is a power grid.

[0217] like Fig.15 As shown, the process may include steps 1502 to 1520.

[0218] Step 1502, determine whether the power supply voltage belongs to the voltage range corresponding to the grid-connected mode, and whether the grid-connected and off-grid switch is in the disconnected state. If so, execute step 1504, if not, execute step 1502.

[0219] It should be noted that when in the automatic switching mode, the EMS automatically detects the power supply voltage and determines whether the power supply voltage belongs to the voltage range corresponding to the grid-connected mode and whether the grid-connected and off-grid switches are in the disconnected state. Optionally, the voltage range corresponding to the grid-connected mode includes 185V to 264V.

[0220] Step 1504: Send a standby instruction to one or more inverter energy storage devices.

[0221] Step 1506, determining whether the duration of the second input voltage of the load falling within the preset power outage range reaches a fourth duration threshold, if so, executing step 1508, if not, re-executing step 1502.

[0222] It should be noted that it takes time for the EMS to send a standby command and for the inverter energy storage device to enter the standby state. After the EMS sends a standby command to one or more inverter energy storage devices, it determines whether the duration of the second input voltage received by the load within the preset power outage range reaches the fourth duration threshold. If the duration of the second input voltage received by the load within the preset power outage range reaches the fourth duration threshold, it can be determined that the inverter energy storage devices included in the energy storage system have no output power. At this time, the distribution equipment is controlled and the off-grid switch is disconnected to avoid ensuring the quality of power provided to the load.

[0223] Step 1508, control the power distribution equipment to control the off-grid switch to close.

[0224] Step 1510, determine whether the on-grid and off-grid switch is in a closed state, if so, execute step 1512, if not, execute step 1516.

[0225] Step 1512, determine whether the duration of the second input voltage received by the load belonging to the voltage range corresponding to the grid-connected mode reaches a second duration threshold, if so, execute step 1514, if not, execute step 1516.

[0226] Step 1514, controlling one or more inverter energy storage devices to operate in the target on-grid and off-grid mode.

[0227] Step 1515, control the power distribution equipment to control the off-grid switch to perform the disconnection action, and determine whether the number of times the power distribution equipment controls the off-grid switch to perform the disconnection action is greater than the preset number. If so, execute step 1518, if not, execute step 1520, and return to execute step 1508.

[0228] Step 1518, determine whether the waiting time reaches the third time threshold, if so, execute step 1502, if not, continue to execute step 1518.

[0229] Optionally, the third duration threshold is 10 minutes.

[0230] Step 1520, wait for a preset time period.

[0231] Please refer to Fig.16 , which shows a schematic diagram of a process of automatically switching to an off-grid mode provided in an embodiment of the present application, wherein the process is applied to EMS, and the power supply system is a power grid.

[0232] like Fig.16 As shown, the process may include steps 1602 to 1620.

[0233] Step 1602, determine whether the power supply voltage belongs to the voltage range corresponding to the off-grid mode, and whether the on-grid and off-grid switch is in a closed state. If so, execute step 1604, if not, execute step 1602.

[0234] It should be noted that when in automatic switching mode, the EMS automatically detects the supply voltage and determines whether the supply voltage belongs to the voltage range corresponding to the grid-connected mode and whether the grid-connected and off-grid switches are in the disconnected state. Optionally, the voltage range corresponding to the off-grid mode includes less than 185V or greater than 264V.

[0235] Step 1604: Send a standby instruction to one or more inverter energy storage devices.

[0236] Step 1606, control the power distribution equipment to control the off-grid switch to perform a disconnection action.

[0237] Step 1608, determine whether the on-grid and off-grid switch is in the off state, if so, execute step 1610, if not, execute step 1614.

[0238] Step 1610, determining whether the duration that the first input voltage of the load belongs to the voltage range corresponding to the off-grid mode reaches a second duration threshold, if so, executing step 1612, if not, executing step 1614.

[0239] Step 1612, controlling one or more inverter energy storage devices to operate in a target on-grid and off-grid mode.

[0240] Step 1614, control the power distribution equipment to control the off-grid switch to close, and determine whether the number of times the power distribution equipment controls the off-grid switch to close is greater than the preset number. If so, execute step 1616, if not, execute step 1618, and return to execute step 1606.

[0241] Step 1616, determine whether the waiting time reaches the third time threshold, if so, execute step 1602, if not, continue to execute step 1616.

[0242] Step 1618, wait for a preset time period.

[0243] It should be noted that the EMS may be preset with a set voltage range. If the voltage falls within the set voltage range, it is equivalent to determining that the voltage belongs to the voltage range corresponding to the grid-connected mode. If the voltage does not fall within the set voltage range, it is equivalent to determining that the voltage belongs to the voltage range corresponding to the off-grid mode. Taking the power supply system as a grid as an example, the set voltage range includes 185V to 264V.

[0244] Please refer to Fig.17, which shows a schematic diagram of the structure of a grid-connected and off-grid switching device provided in an embodiment of the present application, the device can be applied to a control device, and the control device is respectively connected to one or more inverter energy storage devices for communication. Fig.17 As shown, the grid-connected and off-grid switching device 1700 may include a first sending module 1710, a second sending module 1720 and a control module 1730. Among them, the first sending module 1710 is used to send a standby instruction to one or more inverter energy storage devices in response to meeting the target grid-connected and off-grid switching conditions, or in the case of receiving a target switching instruction sent by the terminal device. The target switching instruction is generated by the terminal device in response to the target switching operation. The standby instruction is used to instruct each inverter energy storage device to enter a standby state. In the standby state, the inverter energy storage device does not perform charging and discharging operations. The second sending module 1720 is used to send a first switching instruction to the distribution device when it is determined that each inverter energy storage device enters a standby state. The first switching instruction is used to instruct the distribution device to control the grid-connected and off-grid switch of the distribution device to perform a first switching action corresponding to the target grid-connected and off-grid mode. The control module 1730 is used to control one or more inverter energy storage devices to operate in the target grid-connected and off-grid mode.

[0245] In some embodiments, the on-grid and off-grid switching device 1700 may further include a detection module, wherein the detection module is used to determine that the target on-grid and off-grid switching condition is met if it is detected that the power supply voltage input by the power supply system does not belong to the voltage range corresponding to the on-grid and off-grid mode currently in which one or more inverter energy storage devices are located.

[0246] In some embodiments, the on-grid and off-grid switching device 1700 may further include a first receiving module, and the first receiving module is further configured to not respond to the target switching instruction if a target switching instruction sent by a terminal device is received when the device is in the automatic switching mode.

[0247] In some embodiments, the detection module is further used to, when in manual switching mode, not detect whether the supply voltage does not belong to the voltage range corresponding to the on-grid or off-grid mode in which one or more inverter energy storage devices are currently located.

[0248] In some embodiments, the grid-connected and off-grid switching device 1700 may further include a third sending module. The third sending module may be used to determine status display information and send the status display information to the terminal device so that the terminal device displays the status display information. The status display information includes the grid-connected and off-grid mode currently in which one or more inverter energy storage devices are located, and / or the working status of the power supply system.

[0249] In some embodiments, the on-grid and off-grid switching device 1700 may also include a first judgment module, a fourth sending module and a fifth sending module. The first judgment module is used to judge whether the inverter energy storage device has successfully switched to the target on-grid and off-grid mode according to the first input voltage of the load after sending the first switching instruction to the power distribution device and before controlling one or more inverter energy storage devices to work in the target on-grid and off-grid mode. The fourth sending module is used to send a second switching instruction to the power distribution device if it is determined that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode; the second switching instruction is used to instruct the power distribution device to control the on-grid and off-grid switch to perform a second switching action. The fifth sending module is used to re-execute the step of sending the first switching instruction to the power distribution device if the current moment is a preset time from the moment when the second switching instruction is sent to the power distribution device, until it is determined that the inverter energy storage device has successfully switched to the target on-grid and off-grid mode according to the first input voltage of the load.

[0250] In some embodiments, the on-grid and off-grid switching device 1700 may further include a determination module. The determination module is used to determine that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode if the first input voltage does not belong to the voltage range corresponding to the target on-grid and off-grid mode.

[0251] In some embodiments, the first judgment module is further used to judge whether the inverter energy storage device is successfully switched to the target on-grid and off-grid mode according to the first input voltage and the switching state of the on-grid and off-grid switch.

[0252] In some embodiments, the target on-grid and off-grid mode is the on-grid mode, and the on-grid and off-grid switching device 1700 may further include a second judgment module, which is used to judge whether the second input voltage received by the load belongs to the preset power outage range after sending a standby instruction to one or more inverter energy storage devices and before sending a first switching instruction to the power distribution device. The second sending module is also used to send the first switching instruction to the power distribution device if it is determined that the second input voltage belongs to the preset power outage range.

[0253] In an embodiment of the present application, the on-grid and off-grid switching device includes a first sending module, a second sending module and a control module. First, in response to the target on-grid and off-grid switching condition being met, or in the case of receiving the target switching instruction sent by the terminal device, the first sending module sends a standby instruction to each inverter energy storage device, so that each inverter energy storage device stops receiving or outputting electric energy. Then, in the case of determining that each inverter energy storage device enters the standby state, the second sending module sends the first switching instruction to the distribution device, thereby avoiding the on-grid and off-grid switch action when the inverter energy storage device is performing charging and discharging operations, preventing the generation of reverse current, reducing the impact on the load caused by the sudden change of current or voltage, and avoiding the triggering of the protection mechanism, thereby improving the safety and stability of the energy storage system. After sending the first switching instruction to the distribution device through the second sending module, the control module controls the inverter energy storage device to enter the target on-grid and off-grid mode, so that the inverter energy storage device can output or receive electric energy again, avoiding the occurrence of signal mutations, and further improving the safety and stability of the system.

[0254] The embodiment of the present application also discloses an energy storage system, which includes a power distribution device, a memory, a control device, and one or more inverter energy storage devices. Among them, the inverter energy storage device is used to perform charging and discharging operations. The power distribution device may include an on-grid and off-grid switch, and the power distribution device is used to control the on-grid and off-grid switch to perform a first switching action corresponding to the target on-grid and off-grid mode. The memory stores a computer program. The control device is coupled to the memory, wherein the control device calls the computer program stored in the memory to execute any on-grid and off-grid switching method disclosed in the embodiment of the present application.

[0255] An embodiment of the present application discloses a computer-readable storage medium storing a computer program, wherein when the computer program is executed by the processor, the processor implements any one of the on-grid and off-grid switching methods disclosed in the embodiment of the present application.

[0256] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the 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 for the present application.

[0257] 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.

[0258] 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.

[0259] 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.

[0260] If the above-mentioned 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-accessible memory. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product, which is stored in a memory and includes several requests for a computer device (which can be a personal computer, a server or a network device, etc., specifically a processor in a computer device) to perform some or all of the steps of the above-mentioned methods of various embodiments of the present application.

[0261] Those skilled in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable rewritable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0262] The above is a detailed introduction to a method, device, energy storage system and storage medium for switching between grid and off-grid disclosed in the embodiments 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 methods and application scopes. In summary, the content of this specification should not be understood as limiting the present application.

Claims

1. A method for switching between grid and off-grid, characterized in that: Applied to a control device, the control device is respectively connected to one or more inverter energy storage devices for communication, the method comprising: In response to meeting the target and off-grid switching conditions, or in the case of receiving a target switching instruction sent by the terminal device, sending a standby instruction to the one or more inverter energy storage devices, wherein the target switching instruction is generated by the terminal device in response to the target switching operation, and the standby instruction is used to instruct each of the inverter energy storage devices to enter a standby state, in which the inverter energy storage device does not perform charging and discharging operations; When it is determined that each of the inverter energy storage devices enters the standby state, a first switching instruction is sent to the power distribution device, wherein the first switching instruction is used to instruct the power distribution device to control the grid-connected and off-grid switches of the power distribution device to perform a first switching action corresponding to the target grid-connected and off-grid mode; Control the one or more inverter energy storage devices to operate in the target on-grid and off-grid mode.

2. The method according to claim 1, characterized in that The method further comprises: If it is detected that the power supply voltage input by the power supply system does not belong to the voltage range corresponding to the on-grid or off-grid mode in which the one or more inverter energy storage devices are currently located, it is determined that the target on-grid or off-grid switching condition is met.

3. The method according to claim 2, characterized in that The method further comprises: In the case of being in the automatic switching mode, if a target switching instruction sent by a terminal device is received, the target switching instruction is not responded to; or, In the case of the manual switching mode, it is not detected whether the supply voltage does not belong to the voltage range corresponding to the grid-connected or off-grid mode in which the one or more inverter energy storage devices are currently located.

4. The method according to claim 1, characterized in that: The method further comprises: Determine status display information and send the status display information to a terminal device so that the terminal device displays the status display information; the status display information includes the current on-grid and off-grid mode of the one or more inverter energy storage devices, and / or the working status of the power supply system.

5. The method according to claim 1, characterized in that After sending the first switching instruction to the power distribution device and before controlling the one or more inverter energy storage devices to operate in the target on-grid and off-grid mode, the method includes: Determining whether the inverter energy storage device is successfully switched to the target off-grid mode according to the first input voltage of the load; If it is determined that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode, a second switching instruction is sent to the power distribution device; the second switching instruction is used to instruct the power distribution device to control the on-grid and off-grid switch to perform a second switching action; If the current time is a preset time away from the time of sending the second switching instruction to the power distribution equipment, the step of sending the first switching instruction to the power distribution equipment is re-executed until it is determined that the inverter energy storage device has successfully switched to the target off-grid mode based on the first input voltage of the load.

6. The method according to claim 5, characterized in that The method further comprises: If the first input voltage does not belong to the voltage range corresponding to the target on-grid and off-grid mode, it is determined that the inverter energy storage device has not successfully switched to the target on-grid and off-grid mode.

7. The method according to claim 5, characterized in that The step of judging whether the inverter energy storage device is successfully switched to the target on-grid and off-grid mode according to the first input voltage received by the load includes: According to the first input voltage and the switching state of the on-grid and off-grid switch, it is determined whether the inverter energy storage device is successfully switched to the target on-grid and off-grid mode.

8. The method according to claim 1, characterized in that The target on-grid and off-grid mode is the on-grid mode; After sending a standby instruction to one or more inverter energy storage devices and before sending a first switching instruction to a power distribution device, the method includes: Determining whether the second input voltage of the load falls within a preset power outage range; The sending a first switching instruction to the power distribution equipment includes: If it is determined that the second input voltage belongs to the preset power outage range, a first switching instruction is sent to the power distribution equipment.

9. A grid-connected and off-grid switching device, characterized in that: Applied to a control device, the control device is respectively connected to one or more inverter energy storage devices for communication, the device comprising: A first sending module, configured to send a standby instruction to the one or more inverter energy storage devices in response to meeting the target off-grid switching condition or receiving a target switching instruction sent by a terminal device, wherein the target switching instruction is generated by the terminal device in response to the target switching operation, and the standby instruction is used to instruct each of the inverter energy storage devices to enter a standby state, in which the inverter energy storage device does not perform a charge or discharge operation; A second sending module is used to send a first switching instruction to the power distribution device when it is determined that each of the inverter energy storage devices enters the standby state, wherein the first switching instruction is used to instruct the power distribution device to control the grid-connected and off-grid switches of the power distribution device to perform a first switching action corresponding to the target grid-connected and off-grid mode; A control module is used to control the one or more inverter energy storage devices to operate in the target on-grid and off-grid mode.

10. An energy storage system, characterized in that: include: One or more inverter energy storage devices, wherein the inverter energy storage devices are used to perform charging and discharging operations; A power distribution device, comprising an on-grid and off-grid switch, wherein the power distribution device is used to control the on-grid and off-grid switch to perform a first switching action corresponding to a target on-grid and off-grid mode; a memory, wherein a computer program is stored in the memory; A control device, wherein when the control device executes the computer program, the control device implements the method according to any one of claims 1 to 8.

11. 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 8 is implemented.

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