Energy storage off-grid parallel machine method and energy storage off-grid parallel machine system

Abstract

The application discloses an energy storage off-grid parallel operation method and system, and the energy storage off-grid parallel operation system comprises a signal module and a plurality of energy storage units, and each energy storage unit is provided with a relay interlocking module; each relay interlocking module is connected with an off-grid relay and a grid-connected relay in the corresponding energy storage unit, and is used for controlling the grid-connected relay and the off-grid relay in the same energy storage unit to be mutually exclusive; the signal module is connected between each energy storage unit and each relay interlocking module; the energy storage off-grid parallel operation method comprises the following steps: after the signal module receives a grid-connected signal or an off-grid signal sent by any one of the energy storage units in the energy storage off-grid parallel operation system, all the relay interlocking modules are controlled to act simultaneously, so that the switching of the grid-connected working mode or the off-grid working mode of the energy storage unit is performed. The energy storage off-grid parallel operation method can ensure that the energy storage unit enters the grid-connected working mode or the off-grid working mode at the same time point.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of off-grid control, and particularly relates to a method for energy storage off-grid and on-grid, and an energy storage off-grid and on-grid system based on the method. BACKGROUND

[0002] In the existing energy storage off-grid and on-grid system, the off-grid ports of multiple machines need to be connected in parallel for use. During the off-grid-to-on-grid process, the disconnection and closure of relays are relied on to achieve the process. Because of the large disconnection and closure time error of the relays, it is impossible to ensure that all machines are disconnected from the power grid at the same time. Some energy storage units are in the on-grid mode, and some energy storage units are in the off-grid mode. That is, there may be both on-grid and off-grid modes in the same energy storage off-grid and on-grid system, which may cause system downtime or even damage.

[0003] In order to solve the above problems, the current commonly used solution is to control the logic of the relays through the DSP software of the energy storage system. However, this solution has obvious defects. When there is external hardware or software interference, the software control logic may fail or be delayed, and it is impossible to effectively ensure that the entire energy storage off-grid and on-grid system is in the same working mode.

[0004] That is, the existing solution is to use the software inside the energy storage unit to independently control the working mode of a single energy storage system. As shown in FIG. 1, two energy storage units are taken as an example, and the energy storage units independently control the corresponding on-grid relays and off-grid relays. However, the relays of the two energy storage units cannot be synchronized in mode. Especially in a complex environment or under software delay and hardware interference, it is impossible to ensure that the two independent energy storage units are in the same working mode, and it is inevitable that one energy storage unit works in the on-grid mode while the other energy storage unit works in the off-grid mode, which may cause system downtime or damage. Figure 1 The patent with application number 202111422838.6 adds an external device "fourth control unit" to solve the problem of insufficient load carrying capacity of the on-grid system when carrying a large load; the patent with application number 202410540045.1 is a system software control logic solution in which the slave machine of the on-grid system is controlled and monitored by the master machine. However, none of the above patents addresses the problem of how to solve the synchronization problem of the on-grid working mode or off-grid working mode of multiple energy storage units.

[0005] Therefore, the existing solution of independently controlling the working mode of a single energy storage system still has the risk of system downtime or damage. Therefore, there is an urgent need for an energy storage off-grid and on-grid method and system that can effectively ensure that each independent energy storage unit can enter the on-grid mode at the same time.

[0006]

[0007] ​The disclosure of the foregoing Background Art is given solely for the purpose of aiding in the understanding of the inventive concept and technical solutions of the present application, and does not necessarily pertain to the prior art of the present application. The foregoing Background Art should not be used to evaluate the novelty and inventive step of the present application in the absence of explicit evidence that the above-mentioned content was publicly known before the filing date of the present application. SUMMARY

[0008] In view of this, in order to overcome the defects of the prior art, the purpose of the present application is to provide an energy storage off-grid parallel operation method, which ensures that all energy storage units can simultaneously enter the grid-connected operation mode or off-grid operation mode.

[0009] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0010] An energy storage off-grid parallel operation method, an energy storage off-grid parallel operation system includes a signal module and a plurality of energy storage units, each of the energy storage units is provided with a relay interlocking module; each of the relay interlocking modules is connected with an off-grid relay and a grid-connected relay in the corresponding energy storage unit, for controlling the grid-connected relay and the off-grid relay in the same energy storage unit to be mutually exclusive; the signal module is connected between each energy storage unit and each relay interlocking module, and the signal module is used to control the action of the relay interlocking module according to the state of the energy storage unit;

[0011] The energy storage off-grid parallel operation method includes the following steps:

[0012] After the signal module receives the grid-connected signal or off-grid signal sent by any one of the energy storage units in the energy storage off-grid parallel operation system, it further controls all the relay interlocking modules to act simultaneously to switch to the grid-connected operation mode or off-grid operation mode. In the present application, the mutual exclusion of the relays in the same energy storage unit is that one of the grid-connected relay and the off-grid relay is open, and the other is closed at the same time.

[0013] According to some preferred embodiments of the present application, after the signal module receives the grid-connected signal sent by any one of the energy storage units in the energy storage off-grid parallel operation system, it controls all the relay interlocking modules to act, opens the off-grid relays of all the energy storage units, and at the same time closes the grid-connected relays of all the energy storage units, so as to realize that all the energy storage units simultaneously enter the grid-connected operation mode.

[0014] According to some preferred embodiments of the present application, when all the energy storage units in the energy storage off-grid parallel system are in off-grid operation mode, any one of the energy storage units switches to grid-connected operation mode at the same time, the energy storage unit transmits a grid-connected signal to the signal module, after the signal module receives the grid-connected signal, the signal module sends a grid-connected instruction to all the relay interlocking modules, after all the relay interlocking modules receive the grid-connected instruction, the off-grid relays are opened and the grid-connected relays are closed, so that all the energy storage units enter the grid-connected operation mode at the same time.

[0015] According to some preferred embodiments of the present application, after the signal module receives an off-grid signal sent by any one of the energy storage units in the energy storage off-grid parallel system, the signal module controls all the relay interlocking modules to act, the grid-connected relays of all the energy storage units are opened and the off-grid relays of all the energy storage units are closed, so that all the energy storage units enter the off-grid operation mode at the same time.

[0016] According to some preferred embodiments of the present application, when all the energy storage units in the energy storage off-grid parallel system are in grid-connected operation mode, any one of the energy storage units switches to off-grid operation mode at the same time, the energy storage unit transmits an off-grid signal to the signal module, after the signal module receives the off-grid signal, the signal module sends an off-grid instruction to all the relay interlocking modules, after all the relay interlocking modules receive the off-grid instruction, the grid-connected relays are opened and the off-grid relays are closed, so that all the energy storage units enter the off-grid operation mode at the same time.

[0017] That is, the energy storage unit has an off-grid operation mode and a grid-connected operation mode: in the off-grid operation mode, the off-grid relay is closed and the grid-connected relay is opened; in the grid-connected operation mode, the grid-connected relay is closed and the off-grid relay is opened.

[0018] According to some preferred embodiments of the present application, the signal module comprises a signal bus and an NAND gate arranged between the signal bus and the energy storage unit, the input end of the NAND gate is connected with the energy storage unit, and the output end of the NAND gate is connected with the signal bus.

[0019] According to some preferred embodiments of the present application, each of the energy storage units comprises an energy storage module, the off-grid relay, the grid-connected relay, a grid-connected port and the relay interlocking module; the energy storage module, the off-grid relay, the grid-connected relay and the grid-connected port are arranged in sequence; and the signal bus is connected between the energy storage module and the relay interlocking module.

[0020] According to some preferred embodiments of the present application, the energy storage module has an off-grid state corresponding to the off-grid working mode of the energy storage unit and a grid-connected state corresponding to the grid-connected working mode of the energy storage unit. When the signal bus sends an off-grid instruction to all the relay interlocking modules, it also sends a corresponding off-grid instruction to all the energy storage modules, and all the energy storage modules are switched to the off-grid state at the same time. Similarly, when the signal bus sends a grid-connected instruction to all the relay interlocking modules, it also sends a corresponding grid-connected instruction to all the energy storage modules, and all the energy storage modules are switched to the grid-connected state at the same time.

[0021] According to some preferred embodiments of the present application, the relay interlocking module comprises a first control circuit for controlling the off-grid relay and a second control circuit for controlling the grid-connected relay, and the first control circuit and the second control circuit are connected with the signal bus.

[0022] According to some preferred embodiments of the present application, a NAND gate is arranged on the second control circuit for controlling the off-grid relay and the grid-connected relay to be mutually exclusive.

[0023] According to some preferred embodiments of the present application, the off-grid relay is arranged close to the energy storage module, and the grid-connected relay is arranged close to the grid-connected port, i.e. the energy storage module, the off-grid relay, the grid-connected relay and the grid-connected port are arranged in sequence.

[0024] According to some preferred embodiments of the present application, the energy storage off-grid and grid-connected system comprises an off-grid port connected between the off-grid relay and the grid-connected relay of each energy storage unit. The grid-connected port is used for connecting with the AC power grid, and the off-grid port is used for connecting with the load.

[0025] The present application also provides an energy storage off-grid and grid-connected system based on the above-mentioned energy storage off-grid and grid-connected method.

[0026] Compared with the prior art, the energy storage off-grid and grid-connected method of the present application has the following advantages: a relay interlocking module is arranged for each energy storage unit, so that the off-grid relay and the grid-connected relay in each energy storage unit are mutually exclusive; a signal module is arranged for signal connection with each energy storage unit and each relay interlocking module, which is used for receiving signals of any energy storage unit and can send instructions to all the relay interlocking modules at the same time, thereby ensuring that the energy storage units enter the grid-connected working mode or the off-grid working mode at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is a structural diagram of a parallel system in the prior art;

[0029] Figure 2 This is a structural diagram of an off-grid parallel energy storage system in a preferred embodiment of the present invention; the dotted arrows in the figure indicate the direction of current flow;

[0030] In the accompanying drawings, the reference numerals include: energy storage module-1, signal module-2, signal bus-21, NOR gate-22, relay interlock module-3, first control circuit-31, second control circuit-32, NOR gate-33, off-grid relay-41, grid-connected relay-42, grid-connected port-51, off-grid port-52. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0032] like Figure 2 As shown, the energy storage off-grid parallel system of the present invention includes a signal module 2, multiple energy storage units and an off-grid port 52. Each energy storage unit includes an energy storage module 1, an off-grid relay 41, a grid-connected relay 42, a grid-connected port 51 and a relay interlocking module 3. The off-grid relay 41 is arranged close to the energy storage module 1, and the grid-connected relay 42 is arranged close to the grid-connected port 51, that is, the energy storage module 1, the off-grid relay 41, the grid-connected relay 42 and the grid-connected port 51 are arranged in sequence. The off-grid port 52 is connected between the off-grid relay 41 and the grid-connected relay 42 of each energy storage unit. The grid-connected port 51 is used to connect to the AC power grid, and the off-grid port 52 is used to connect to the load. Through the signal module 2 and the relay interlocking module 3, the energy storage off-grid parallel system of the present invention can realize the synchronous action of the relays of multiple energy storage units, and then control all energy storage units to enter the grid-connected working mode or the off-grid working mode at the same time.

[0033] Each relay interlocking module 3 is connected with off-grid relay 41 and grid-connected relay 42 in the corresponding energy storage unit, for controlling the mutual exclusion of grid-connected relay 42 and off-grid relay 41 in the same energy storage unit. In the present application, the mutual exclusion of relays in the same energy storage unit is that one of grid-connected relay 42 and off-grid relay 41 is open and the other is closed at the same time. Signal module 2 is connected between each energy storage unit and each relay interlocking module 3.

[0034] Specifically, the signal module 2 in the present application comprises signal bus 21 and NAND gate 22 arranged between signal bus 21 and energy storage unit, the input end of NAND gate 22 is connected with energy storage module 1, and the output end of NAND gate 22 is connected with signal bus 21. At the same time, signal bus 21 is connected between energy storage module 1 and relay interlocking module 3, for simultaneously receiving the signal of each independent energy storage unit, and sending the instruction of the system to each independent relay interlocking module 3 and energy storage module 1, the relay interlocking module 3 receives the instruction and acts, realizing hardware synchronous switching, and the energy storage module 1 receives the instruction and switches the state, realizing software signal synchronization.

[0035] The energy storage unit has off-grid working mode and grid-connected working mode: in off-grid working mode, off-grid relay 41 is closed and grid-connected relay 42 is open; in grid-connected working mode, grid-connected relay 42 is closed and off-grid relay 41 is open. Energy storage module 1 has off-grid state corresponding to off-grid working mode of the energy storage unit and grid-connected state corresponding to grid-connected working mode of the energy storage unit. When signal bus 21 sends off-grid instruction to all relay interlocking modules 3, it also sends corresponding off-grid instruction to all energy storage modules 1, and all energy storage modules 1 are simultaneously switched to off-grid state. Similarly, when signal bus 21 sends grid-connected instruction to all relay interlocking modules 3, it also sends corresponding grid-connected instruction to all energy storage modules 1, and all energy storage modules 1 are simultaneously switched to grid-connected state.

[0036] That is, in addition to being connected through NAND gate 22, signal bus 21 and energy storage module 1 also need to be directly connected, so that energy storage module 1 can directly receive the feedback instruction of signal bus 21. After signal bus 21 receives the signal of energy storage module 1 through NAND gate 22, it simultaneously sends instructions to relay interlocking module 3 and energy storage module 1, relay interlocking module 3 receives the instruction to control the action of the relay to realize hardware synchronous switching, and energy storage module 1 receives the instruction to control the state switching of energy storage module 1 to realize software signal synchronization.

[0037] The relay interlock module 3 includes a first control circuit 31 for controlling the off-grid relay 41 and a second control circuit 32 for controlling the grid-connected relay 42. Both the first control circuit 31 and the second control circuit 32 are connected to the signal bus 21 and are used to control the opening and closing of the grid-connected relay 42 and the off-grid relay 41. The second control circuit 32 is provided with a NOT gate 33 to control the mutual exclusion of the off-grid relay 41 and the grid-connected relay 42, that is, to ensure that only one of them is closed at a time and the other is open.

[0038] An energy storage off-grid parallel method based on the above energy storage off-grid parallel system of the present invention comprises the following steps:

[0039] After receiving the grid-connected signal or off-grid signal sent by any energy storage unit in the energy storage off-grid parallel system, the signal module 2 controls all the relay interlock modules 3 to operate simultaneously to switch the grid-connected working mode or off-grid working mode of the energy storage unit.

[0040] In some embodiments, after the signal module 2 receives the grid-connected signal sent by any energy storage unit in the energy storage off-grid parallel system, it controls all relay interlocking modules 3 to operate, disconnect the off-grid relays 41 of all energy storage units, and simultaneously close the grid-connected relays 42 of all energy storage units, so that all energy storage units enter the grid-connected working mode at the same time.

[0041] Specifically, when all energy storage units in the energy storage off-grid parallel system are in the off-grid working mode, when any one of the energy storage units switches to the grid-connected working mode, the energy storage unit transmits the grid-connected signal to the signal module 2. After receiving the grid-connected signal, the signal module 2 sends a grid-connected instruction to all relay interlocking modules 3. After all relay interlocking modules 3 receive the grid-connected instruction, they disconnect the off-grid relay 41 and close the grid-connected relay 42 at the same time, so that all energy storage units enter the grid-connected working mode at the same time.

[0042] More specifically, when all energy storage units in the off-grid parallel energy storage system are in the off-grid working mode and all energy storage modules 1 are in the off-grid state, when any one of the energy storage units switches to the grid-connected working mode, the corresponding energy storage module 1 switches to the grid-connected state. The energy storage module 1 transmits the grid-connected signal to the signal bus 21 through the NOR gate 22 of the signal module 2. After receiving the grid-connected signal, the signal bus 21 sends a grid-connected instruction to all relay interlocking modules 3 and all energy storage modules 1. After receiving the grid-connected instruction, all relay interlocking modules 3 disconnect the off-grid relay 41 and close the grid-connected relay 42 at the same time, realizing hardware synchronous switching; at the same time, all energy storage modules 1 switch to the grid-connected state at the same time after receiving the grid-connected instruction, realizing software signal synchronization, and thus realizing that all energy storage units enter the grid-connected working mode at the same time.

[0043] In other embodiments, after the signal module 2 receives the off-grid signal sent by any energy storage unit in the energy storage off-grid parallel system, it controls all the relay interlocking modules 3 to operate, disconnects the grid-connected relays 42 of all energy storage units, and simultaneously closes the off-grid relays 41 of all energy storage units, so that all energy storage units enter the off-grid working mode at the same time.

[0044] Specifically, when all energy storage units in the energy storage off-grid parallel system are in the grid-connected working mode, when any one of the energy storage units switches to the off-grid working mode, the energy storage unit transmits the off-grid signal to the signal module 2. After receiving the off-grid signal, the signal module 2 sends an off-grid instruction to all relay interlocking modules 3. After all relay interlocking modules 3 receive the off-grid instruction, they disconnect the grid-connected relay 42 and close the off-grid relay 41 at the same time, so that all energy storage units enter the off-grid working mode at the same time.

[0045] More specifically, when all energy storage units in the off-grid parallel energy storage system are in the grid-connected working mode and all energy storage modules 1 are in the grid-connected state, when any one of the energy storage units switches to the off-grid working mode, the corresponding energy storage module 1 switches to the off-grid state. The energy storage module 1 transmits the off-grid signal to the signal bus 21 through the NOR gate 22 of the signal module 2. After receiving the off-grid signal, the signal bus 21 sends an off-grid instruction to all relay interlocking modules 3 and all energy storage modules 1. After receiving the off-grid instruction, all relay interlocking modules 3 disconnect the grid-connected relay 42 and close the off-grid relay 41 at the same time, realizing hardware synchronous switching; at the same time, all energy storage modules 1 switch to the off-grid state at the same time after receiving the off-grid instruction, realizing software signal synchronization, and thus realizing that all energy storage units enter the off-grid working mode at the same time.

[0046] Example 1: Figure 2 As shown, the energy storage off-grid parallel system of this embodiment includes a signal module 2, multiple energy storage units, and an off-grid port 52. Each energy storage unit includes an energy storage module 1, an off-grid relay 41, a grid-connected relay 42, a grid-connected port 51, and a relay interlock module 3. The off-grid relay 41 is located near the energy storage module 1, and the grid-connected relay 42 is located near the grid-connected port 51. That is, the energy storage module 1, the off-grid relay 41, the grid-connected relay 42, and the grid-connected port 51 are located in this order. The off-grid port 52 is connected between the off-grid relay 41 and the grid-connected relay 42 of each energy storage unit. The grid-connected port 51 is used to connect to the AC grid, and the off-grid port 52 is used to connect to the load.

[0047] Each relay interlocking module 3 is connected with off-grid relay 41 and grid-connected relay 42 in the corresponding energy storage unit, for controlling the off-grid relay 41 and grid-connected relay 42 in the same energy storage unit to be mutually exclusive. Signal module 2 is signal connected with each energy storage unit and each relay interlocking module 3. Specifically, signal module 2 includes signal bus 21 and NOR gate 22 arranged between signal bus 21 and energy storage module 1, the input end of NOR gate 22 is connected with energy storage module 1, and the output end of NOR gate 22 is connected with signal bus 21. Signal bus 21 is connected between energy storage module 1 and relay interlocking module 3, for simultaneously receiving the signal of each independent energy storage unit, and sending the instruction of the system to each independent relay interlocking module 3 and energy storage module 1, the relay interlocking module 3 receives the instruction and acts, realizing hardware synchronous switching, and the energy storage module 1 receives the instruction and switches the state, realizing software signal synchronization.

[0048] The relay interlocking module 3 in the embodiment includes first control circuit 31 for controlling off-grid relay 41 and second control circuit 32 for controlling grid-connected relay 42, and first control circuit 31 and second control circuit 32 are both connected with signal bus 21, for controlling the opening and closing of off-grid relay 41 and grid-connected relay 42. NOR gate 33 is arranged on second control circuit 32, for controlling off-grid relay 41 and grid-connected relay 42 to be mutually exclusive, that is, to ensure that only one of them is closed at the same time, and the other is opened.

[0049] Embodiment 2: The embodiment provides an energy storage off-grid and grid-connected method based on the above-mentioned energy storage off-grid and grid-connected system, for realizing the synchronous switching of all energy storage units from off-grid working mode to grid-connected working mode, including the following steps:

[0050] When any one of the energy storage units in the energy storage off-grid and grid-connected system is switched to grid-connected working mode, the energy storage unit transmits grid-connected signal to signal module 2, signal module 2 receives the grid-connected signal, sends grid-connected instruction to all relay interlocking modules 3, all relay interlocking modules 3 receive the grid-connected instruction, off-grid relay 41 is opened, and grid-connected relay 42 is closed at the same time, realizing that all energy storage units enter grid-connected working mode at the same time.

[0051] Based on the component structure of the energy storage off-grid and grid-connected system in embodiment 1, the energy storage off-grid and grid-connected method switched from off-grid working mode to grid-connected working mode in the embodiment includes the following steps:

[0052] When all the energy storage units in the energy storage off-grid parallel system are in off-grid operation mode, all the energy storage modules 1 are in off-grid state, and any one of the energy storage units is switched to grid-connected operation mode, the corresponding energy storage module 1 is switched to grid-connected state. The energy storage module 1 transmits the grid-connected signal to the signal bus 21 through the NOR gate 22 of the signal module 2. After the signal bus 21 receives the grid-connected signal, it sends a grid-connected instruction to all the relay interlocking modules 3 and all the energy storage modules 1. After all the relay interlocking modules 3 receive the grid-connected instruction, the off-grid relay 41 and the grid-connected relay 42 are controlled by the NOR gate 33 on the first control circuit 31 and the second control circuit 32 to be mutually exclusive, that is, the off-grid relay 41 is opened, and the grid-connected relay 42 is closed, realizing hardware synchronous switching. At the same time, all the energy storage modules 1 receive the grid-connected instruction and are switched to the grid-connected state at the same time, realizing software signal synchronization, and then realizing that all the energy storage units enter the grid-connected operation mode at the same time.

[0053] Embodiment 3: The embodiment provides an energy storage off-grid parallel method based on the above-mentioned energy storage off-grid parallel system, which realizes the switching of the energy storage unit from the grid-connected operation mode to the off-grid operation mode, and includes the following steps:

[0054] When any one of the energy storage units in the energy storage off-grid parallel system is switched to the off-grid operation mode, the energy storage unit transmits the off-grid signal to the signal module 2. After the signal module 2 receives the off-grid signal, it sends an off-grid instruction to all the relay interlocking modules 3. After all the relay interlocking modules 3 receive the off-grid instruction, the grid-connected relay 42 is opened, and the off-grid relay 41 is closed, realizing that all the energy storage units enter the off-grid operation mode at the same time.

[0055] Based on the component structure of the energy storage off-grid parallel system in Embodiment 1, the energy storage off-grid parallel method switched from the grid-connected operation mode to the off-grid operation mode in the embodiment includes the following steps:

[0056] When all the energy storage units in the energy storage off-grid parallel system are in the grid-connected working mode, all the energy storage modules 1 are in the grid-connected state, and any one of the energy storage units is switched to the off-grid working mode, the corresponding energy storage module 1 is switched to the off-grid state, the energy storage module 1 transmits the off-grid signal to the signal bus 21 through the NOR gate 22 of the signal module 2, the signal bus 21 receives the off-grid signal and sends the off-grid instruction to all the relay interlocking modules 3 and all the energy storage modules 1, all the relay interlocking modules 3 receive the off-grid instruction and control the off-grid relay 41 and the grid-connected relay 42 to be mutually exclusive through the NOT gate 33 on the first control circuit 31 and the second control circuit 32, that is, the grid-connected relay 42 is disconnected, and the off-grid relay 41 is closed, so that the hardware synchronous switching is realized; at the same time, all the energy storage modules 1 receive the off-grid instruction and are switched to the off-grid state at the same time, so that the software signal synchronization is realized, and then all the energy storage units enter the off-grid working mode at the same time.

[0057] The energy storage off-grid parallel method of the application sets the relay interlocking module 3 for each energy storage unit, so that the off-grid relay 41 and the grid-connected relay 42 in each energy storage unit are mutually exclusive, and the signal module 2 connected with each energy storage unit and each relay interlocking module 3 is arranged, the signal module 2 receives the grid-connected signal or the off-grid signal sent by any one of the energy storage units in the energy storage off-grid parallel system, controls all the relay interlocking modules 3 to act, and switches the grid-connected working mode or the off-grid working mode, so that all the energy storage units enter the grid-connected working mode or the off-grid working mode at the same time. Specifically, the signal module 2 receives the grid-connected signal sent by any one of the energy storage units in the energy storage off-grid parallel system, controls all the relay interlocking modules 3 to act, disconnects the off-grid relay 41 of all the energy storage units, and closes the grid-connected relay 42 of all the energy storage units, so that all the energy storage units enter the grid-connected working mode at the same time; or the signal module 2 receives the off-grid signal sent by any one of the energy storage units in the energy storage off-grid parallel system, controls all the relay interlocking modules 3 to act, disconnects the grid-connected relay 42 of all the energy storage units, and closes the off-grid relay 41 of all the energy storage units, so that all the energy storage units enter the off-grid working mode at the same time. When the relay interlocking module 3 receives the instruction and acts, the energy storage module 1 also receives the instruction of the signal module 2 to switch the state, so that the software and the hardware are switched at the same time.

[0058] The above embodiments prepared by the method of the application are only for illustrating the technical concept and characteristics of the application, the purpose is to enable the person skilled in the art to understand the content of the application and to implement it, and cannot limit the protection scope of the application. Any equivalent changes or modifications made according to the spirit and essence of the application should be covered within the protection scope of the application.

Claims

1. A method for off-grid parallel operation of energy storage, characterized in that: The energy storage off-grid parallel system includes a signal module and multiple energy storage units, each of which is provided with a corresponding relay interlocking module; each relay interlocking module is connected to the off-grid relay and the grid-connected relay in the corresponding energy storage unit, and is used to control the mutual exclusion of the grid-connected relay and the off-grid relay in the same energy storage unit; the signal module is connected between each energy storage unit and each relay interlocking module; The energy storage off-grid parallel method comprises the following steps: After receiving the grid-connected signal or off-grid signal sent by any energy storage unit in the energy storage off-grid parallel system, the signal module controls all relay interlock modules to operate simultaneously to switch the grid-connected working mode or off-grid working mode of the energy storage unit; The signal module includes a signal bus and a NOR gate provided between the signal bus and the energy storage unit, wherein the input end of the NOR gate is connected to the energy storage unit, and the output end of the NOR gate is connected to the signal bus; each of the energy storage units includes an energy storage module, and the signal bus is connected between the energy storage module and the relay interlock module; The relay interlock module includes a first control circuit for controlling the off-grid relay and a second control circuit for controlling the grid-connected relay. The first control circuit and the second control circuit are both connected to a signal bus; and a NOT gate is provided on the second control circuit.

2. The energy storage off-grid parallel method according to claim 1, characterized in that: After receiving the grid-connected signal sent by any energy storage unit in the energy storage off-grid parallel system, the signal module controls the operation of all relay interlocking modules, disconnects the off-grid relays of all energy storage units, and simultaneously closes the grid-connected relays of all energy storage units, so that all energy storage units enter the grid-connected working mode at the same time.

3. The energy storage off-grid parallel method according to claim 1 or 2, characterized in that: When all energy storage units in the energy storage off-grid parallel system are in the off-grid working mode, when any one of the energy storage units switches to the grid-connected working mode, the energy storage unit transmits the grid-connected signal to the signal module. After receiving the grid-connected signal, the signal module sends a grid-connected instruction to all relay interlocking modules. After receiving the grid-connected instruction, all relay interlocking modules disconnect the off-grid relay and close the grid-connected relay at the same time, so that all energy storage units enter the grid-connected working mode at the same time.

4. The energy storage off-grid parallel method according to claim 1, characterized in that: After receiving the off-grid signal sent by any energy storage unit in the off-grid parallel energy storage system, the signal module controls the actions of all relay interlock modules, disconnects the grid-connected relays of all energy storage units, and simultaneously closes the off-grid relays of all energy storage units, so that all energy storage units enter the off-grid working mode at the same time.

5. The energy storage off-grid parallel method according to claim 1 or 4, characterized in that: When all energy storage units in the energy storage off-grid parallel system are in the grid-connected working mode, when any one of the energy storage units switches to the off-grid working mode, the energy storage unit transmits an off-grid signal to the signal module. After receiving the off-grid signal, the signal module sends an off-grid instruction to all relay interlocking modules. After receiving the off-grid instruction, all relay interlocking modules disconnect the grid-connected relay and close the off-grid relay at the same time, so that all energy storage units enter the off-grid working mode at the same time.

6. The energy storage off-grid parallel method according to claim 1, characterized in that: Each of the energy storage units includes the energy storage module, the off-grid relay, the grid-connected relay, a grid-connected port and the relay interlock module.

7. The energy storage off-grid parallel method according to claim 6, characterized in that: The energy storage module has an off-grid state corresponding to the off-grid working mode of the energy storage unit and a grid-connected state corresponding to the grid-connected working mode of the energy storage unit; when the signal bus sends an off-grid instruction to all relay interlocking modules, it also sends a corresponding off-grid instruction to all energy storage modules, and all energy storage modules switch to the off-grid state at the same time; when the signal bus sends a grid-connected instruction to all relay interlocking modules, it also sends a corresponding grid-connected instruction to all energy storage modules, and all energy storage modules switch to the grid-connected state at the same time.

8. The energy storage off-grid parallel method according to claim 6, characterized in that: The off-grid relay is arranged close to the energy storage module, and the grid-connected relay is arranged close to the grid-connected port.

9. The energy storage off-grid parallel method according to claim 6, characterized in that: The energy storage off-grid parallel system includes an off-grid port, which is connected between the off-grid relay and the grid-connected relay of each energy storage unit.

10. An off-grid energy storage parallel system using the off-grid energy storage parallel method according to any one of claims 1 to 9.

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