Power-down control method and device of energy storage system, controller and energy storage system

Abstract

The invention provides a power-down control method and device of an energy storage system, a controller and the energy storage system. The method comprises the following steps: when a mains supply abnormal signal sent by the uninterruptible power supply is monitored, controlling the energy storage converter to stop working; after the energy storage converter stops working, a contactor of the switch unit is controlled to be disconnected so as to disconnect the connection between the corresponding battery cluster and the energy storage converter; according to the method, communication between the uninterruptible power supply and the battery management system is established, when the mains supply is powered off, the uninterruptible power supply can timely send the mains supply abnormal signal to the battery management system, so that the battery management system closes the PCS, and the switch unit is disconnected after the two ends of the switch unit are not electrified; therefore, the phenomenon of live-line forced tripping of the switch unit contactor is avoided, the contactor is prevented from being damaged, and safe and stable operation of an energy storage system is ensured.

Description

Technical Field

[0001] The present invention relates to the field of energy storage technology, and in particular to a power-off control method, device, controller and energy storage system of an energy storage system. Background Art

[0002] The energy storage system includes a battery cluster and a power conversion system (PCS). The PCS can realize the charging and discharging of the battery cluster, for example, converting the electric energy of the battery cluster and then connecting it to the grid.

[0003] At present, the energy storage system uses UPS (Uninterruptible Power System) as its auxiliary power supply, which mainly powers the power-off control system of the energy storage system. When the mains power fails, the BMS (Battery Management System) of the energy storage system will trigger the third-level protection. Under this protection, the contactor in the switch unit between the battery cluster and the energy storage inverter will be energized and forced to disconnect, causing the contactor to arc, and then causing failure or damage to the contactor. Summary of the invention

[0004] The embodiments of the present invention provide a power-off control method, device, controller and energy storage system for an energy storage system to solve the technical problem of device damage caused by forced disconnection of a live contactor when the mains power fails.

[0005] In a first aspect, an embodiment of the present invention provides a power-off control method for an energy storage system, wherein the energy storage system includes an uninterruptible power supply, an energy storage converter, at least one battery module, and a battery management system corresponding to each battery module; the battery module includes a switch unit and a battery cluster; each battery cluster is respectively connected to one end of the corresponding switch unit, and the other end of each switch unit is connected to a DC terminal of the energy storage converter; the uninterruptible power supply is used to supply power to an auxiliary power supply of the energy storage system; the switch unit includes a contactor;

[0006] The method is applied to the battery management system, comprising:

[0007] When an abnormal mains power signal sent by the uninterruptible power supply is detected, controlling the energy storage converter to stop working;

[0008] After the energy storage converter stops working, the contactor of the switch unit is controlled to be disconnected to disconnect the corresponding battery cluster from the energy storage converter.

[0009] In a second aspect, an embodiment of the present invention provides a power-off control device for an energy storage system, wherein the energy storage system includes an uninterruptible power supply, an energy storage converter, at least one battery module, and a battery management system corresponding to each battery module; the battery module includes a switch unit and a battery cluster; each battery cluster is respectively connected to one end of the corresponding switch unit, and the other end of each switch unit is connected to the DC end of the energy storage converter; the uninterruptible power supply is used to supply power to an auxiliary power supply of the energy storage system; the switch unit includes a contactor;

[0010] The device is applied to the battery management system, comprising:

[0011] An energy storage converter control module, used to control the energy storage converter to stop working when an abnormal mains power signal sent by the uninterruptible power supply is detected;

[0012] The switch unit control module is used to control the contactor of the switch unit to disconnect after the energy storage converter stops working, so as to disconnect the corresponding battery cluster from the energy storage converter.

[0013] In a third aspect, an embodiment of the present invention provides a controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the power-off control method for the energy storage system as described in any possible implementation of the first aspect above are implemented.

[0014] In a fourth aspect, an embodiment of the present invention provides an energy storage system, comprising the controller as described above.

[0015] The embodiment of the present invention provides a power-off control method, device, controller and energy storage system of an energy storage system. When the method detects a mains power abnormality signal sent by the uninterruptible power supply, the energy storage converter is controlled to stop working; after the energy storage converter stops working, the contactor of the switch unit is controlled to be disconnected to disconnect the connection between the corresponding battery cluster and the energy storage converter; the above method establishes communication between the uninterruptible power supply and the battery management system. When the mains power is off, the uninterruptible power supply can send the mains power abnormality signal to the battery management system in time, so that the battery management system shuts down the PCS, ensures that the two ends of the switch unit are not energized before disconnecting the switch unit, thereby avoiding the phenomenon of forced disconnection of the switch unit contactor with power on, avoiding damage to the contactor, and ensuring the safe and stable operation of the energy storage system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 is a schematic structural diagram of a microgrid system provided by an embodiment of the present invention;

[0018] Figure 2 is a flow chart of an implementation of a power-off control method for an energy storage system provided by an embodiment of the present invention;

[0019] Figure 3 is a schematic structural diagram of a high-voltage box provided in an embodiment of the present invention;

[0020] Figure 4 is a structural schematic diagram of a power-off control device for an energy storage system provided by an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of a controller provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0024] Figure 1 A schematic diagram of the structure of an energy storage system provided in an embodiment of the present invention. Figure 1 As shown, the energy storage system includes an uninterruptible power supply UPS, an energy storage converter PCS, at least one battery module and a battery management system BMS corresponding to each battery module, and an EMS (Energy Management System); the battery module includes at least one switch unit and a battery cluster; and each battery cluster is connected to one end of the corresponding switch unit, and the other end of each switch unit is connected to the DC end of the energy storage converter, and the AC end of the energy storage converter is used to connect to the mains. The uninterruptible power supply UPS is used to supply power to the auxiliary power supply of the energy storage system; the PCS and UPS are respectively connected to the BMS in communication, and the BMS is connected to the EMS in communication.

[0025] The switch unit may include a DCDC module, one end of the DCDC module is connected to the battery cluster, and the other end is connected to the DC end of the energy storage converter, and the DCDC module includes a contactor.

[0026] In another embodiment, the switch unit may also be a high-voltage box, one end of which is connected to the battery cluster, and the other end is connected to the energy storage inverter, and the high-voltage box includes a contactor. When the contactor is closed, the battery cluster and the energy storage inverter are connected, and when the contactor is disconnected, the battery cluster and the energy storage inverter are disconnected.

[0027] In another embodiment, the switch unit may also be a high-voltage box with a DCDC circuit. Specifically, the high-voltage box includes a main positive contactor, a main and auxiliary contactor, and a DCDC circuit, and the first end of the main positive contactor, the first end of the main negative contactor, and the first DC end of the DCDC circuit are all connected to the battery cluster, the second end of the main negative contactor is connected to one end of the target resistor, and the other end of the target resistor, the second end of the main positive contactor, and the second DC end of the DCDC circuit are all connected to the DC end of the energy storage inverter.

[0028] Figure 2 FIG. 1 shows a schematic diagram of the implementation flow of the power-off control method for the energy storage system provided in this embodiment, which is applied to the battery management system BMS. Figure 2 The method is described in detail as follows:

[0029] S101: When an abnormal mains power signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working.

[0030] In this embodiment, the uninterruptible power supply is a constant voltage and frequency power supply with an energy storage device and an inverter as the main component, which is used to power the battery management system. When the mains input is normal, the UPS stabilizes the mains and supplies it to the BMS. At this time, the UPS is an AC mains voltage stabilizer, and it also charges the UPS battery; when the mains power is interrupted, the UPS immediately uses the power of the UPS battery to continue to supply AC power to the load through an inverter conversion method, so that the load maintains normal operation and protects the load software and hardware from damage. The energy storage inverter can control the charging and discharging process of the battery cluster and perform AC-DC conversion.

[0031] Specifically, the uninterruptible power supply UPS and the battery management system BMS can communicate through CAN, RS485 and dry contacts. When the uninterruptible power supply UPS is working normally, CAN or RS485 communication technology can be selected to communicate with the BMS. When the uninterruptible power supply UPS detects an abnormal signal, the communication protection is triggered, and the UPS abnormal signal is sent to the battery management system BMS through the dry contact. The UPS abnormal signal includes the AC abnormal signal. If the BMS detects the AC abnormal signal sent by the uninterruptible power supply through the dry contact, the energy storage converter PCS is controlled to stop working to avoid the contactor of the switch unit from being energized and forced to disconnect and arc.

[0032] Specifically, when the uninterruptible power supply detects that the mains power is off or the mains voltage is too low, it will generate a mains power abnormality signal.

[0033] S102: After the energy storage converter stops working, controlling the contactor of the switch unit to be disconnected to disconnect the corresponding battery cluster from the energy storage converter.

[0034] In this embodiment, taking the high-voltage box as an example, Figure 3 A specific structural diagram of a high-voltage box is shown. Figure 3 As shown, after the energy storage inverter stops working, it sends a stop signal to the BMS. After the BMS detects the stop signal sent by the energy storage inverter, it controls the main positive contactor and the main negative contactor in the high-voltage box to disconnect. At this time, there is no electricity at both ends of the contactor, and the disconnection action can be performed.

[0035] It can be seen from the above embodiments that the above method establishes communication between the uninterruptible power supply and the battery management system. When the mains power is lost, the uninterruptible power supply UPS can promptly send a mains power abnormality signal to the battery management system BMS, so that the battery management system BMS shuts down the PCS, ensures that both ends of the high-voltage box are not energized before disconnecting the switch unit, thereby avoiding the phenomenon of forced disconnection of the high-voltage box contactor, avoiding damage to the contactor, and ensuring the safe and stable operation of the energy storage system.

[0036] In a possible implementation, an implementation process of S101 includes:

[0037] If the UPS battery abnormality signal sent by the uninterruptible power supply is not detected within a preset time interval after the mains abnormality signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after a first preset time.

[0038] In this embodiment, the UPS abnormal signal also includes a UPS battery abnormal signal. The battery is a battery inside the uninterruptible power supply UPS. When the uninterruptible power supply UPS detects that the electrical parameters of its internal battery are lower than the preset electrical parameter threshold, it will generate a UPS battery abnormal signal, wherein the electrical parameter may include the battery voltage or the battery SOC (State of Charge) value. When the UPS detects the UPS abnormal signal, it triggers the communication protection. In the communication protection state, the UPS abnormal signal is sent to the BMS through the dry contact.

[0039] When the BMS detects an abnormal signal from the AC power supply but does not detect an abnormal signal from the UPS battery within the preset time interval, the first preset time timing is started. During the first preset time timing, since the UPS backup battery has power, the energy storage system can be normally controlled during this period. After the first preset time is reached, the energy storage inverter PCS is controlled to stop working, and then the contactor of the energy storage system is turned off to complete the power-off protection of the energy storage system.

[0040] Specifically, the first preset time may be 10 to 15 minutes.

[0041] In this embodiment, the first preset time can also be determined by the electrical parameters of the UPS battery. Specifically, when the UPS does not detect an abnormal signal of the UPS battery, the current electrical parameters of the UPS battery are sent to the BMS. The BMS determines the first preset time based on the difference between the current electrical parameters and the minimum electrical parameter threshold, as well as the load power of the UPS. In this way, the use time of the energy storage system can be extended when the mains power is abnormal. Among them, when the electrical parameter is the SOC value, the minimum SOC threshold can be 10% to 20%.

[0042] In a possible implementation, another implementation process of S101 includes:

[0043] If the abnormal mains power signal and the abnormal UPS battery signal sent by the uninterruptible power supply are monitored within a preset time interval, the energy storage converter is controlled to stop working.

[0044] Specifically, if the BMS detects the AC power abnormality signal and UPS battery abnormality signal sent by the UPS within the preset time, it means that the AC power is off and the electrical parameters of the UPS battery are lower than the preset electrical parameter threshold. The energy storage inverter needs to be stopped immediately to avoid the contactor arcing when the UPS power is off and the energy storage system is powered off for protection.

[0045] The specific implementation process of S101 includes:

[0046] If no off-grid debugging signal is detected, then when no UPS battery abnormality signal sent by the uninterruptible power supply is detected within a preset time interval after the mains abnormality signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after a first preset time;

[0047] If an off-grid debugging signal is detected, when an abnormal mains power signal and an abnormal UPS battery signal sent by the uninterruptible power supply are detected within a preset time interval, the energy storage converter is controlled to stop working.

[0048] In this embodiment, the energy storage system needs to be debugged off-grid before formal operation. At this time, the energy storage system is not connected to the power grid. In order to avoid the BMS from powering off for protection due to the detection of abnormal mains signal during off-grid debugging, this embodiment can set an off-grid debugging button on the human-computer interaction interface of the EMS. After the user triggers the off-grid debugging button, the EMS sends an off-grid debugging signal to the BMS corresponding to each battery cluster. After the BMS detects the off-grid debugging signal, the off-grid debugging bit is set to 1. During the off-grid debugging position 1, if only the abnormal mains signal is detected, the power-off control method is not executed, and the user can use the UPS battery to debug the energy storage system off-grid; if the abnormal mains signal and the abnormal UPS battery signal sent by the uninterruptible power supply are detected within the preset time interval, the energy storage converter is controlled to stop working. When the user presses the off-grid debugging button again, the off-grid debugging bit is set to zero. At this time, if the abnormal UPS battery signal sent by the uninterruptible power supply is not detected within the preset time interval after the abnormal mains signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after the first preset time.

[0049] In a possible implementation, the specific implementation process of S101 includes:

[0050] If an abnormal mains power signal sent by the uninterruptible power supply is monitored, a stop signal is sent to the energy storage converter; the stop signal is used to instruct the energy storage converter to prohibit charging and discharging, and shut down after stopping charging and discharging.

[0051] In this embodiment, after the BMS detects an abnormal signal from the mains, it triggers the BMS level 3 protection. In addition to controlling the energy storage converter to stop working, it can also control the bottom-level slave control BMU (Battery Management Unit) to stop working, that is, stop collecting various types of information of single cells, stop calculating and analyzing the battery's SOC and SOH (state of health), stop actively balancing single cells, and upload single cell abnormal information to the main control. Control the middle-layer main control computer BCU (Battery Control Unit) to stop working, that is, stop collecting various single cell information uploaded by BMU, stop collecting battery group information, and stop calculating and analyzing the battery group's SOC and SOH. Control the master control BAU (Battery Array Unit) to stop working, that is, stop the overall coordination within the system and the external information interaction with the PCS.

[0052] In a possible implementation manner, after S102, the method provided in this embodiment further includes:

[0053] Obtain the mains power recovery signal sent by the UPS, control the switch unit to close, control the energy storage converter to start and work according to the charge and discharge instructions.

[0054] In a possible implementation manner, before S101, the method provided in this embodiment further includes:

[0055] Acquire a UPS abnormality signal sent by the uninterruptible power supply through a dry contact after detecting a UPS abnormality;

[0056] The UPS abnormal signal includes a mains abnormal signal, a UPS fault signal and a UPS battery abnormal signal.

[0057] In this embodiment, when the UPS is abnormal, a UPS abnormal signal is sent to the BMS through a dry contact, so that the user can learn the abnormal cause of the UPS in time, avoiding the problem that the user does not understand the cause of the UPS crash and causes a long maintenance time.

[0058] In a possible implementation, the energy storage system further includes an energy management system; after obtaining a UPS abnormality signal sent by the uninterruptible power supply through a dry contact after detecting a UPS abnormality, the method provided in this embodiment further includes:

[0059] The UPS abnormal signal is sent to the energy management system so that the energy management system displays the UPS abnormal signal.

[0060] In this embodiment, the EMS is connected to each BMS via Ethernet. The EMS is used to receive UPS abnormality signals uploaded by each BMS and display them on a display screen of the EMS, so that a user can remotely view the cause of the UPS abnormality.

[0061] It should be understood that the order of execution of the steps in the above embodiment 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 embodiment of the present invention.

[0062] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0063] Figure 3 The following is a schematic diagram showing the structure of a power-off control device for an energy storage system provided by an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, which are described in detail as follows:

[0064] like Figure 3 As shown, the power-off control device 100 of the energy storage system includes:

[0065] The energy storage converter control module 110 is used to control the energy storage converter to stop working when an abnormal mains power signal sent by the uninterruptible power supply is detected;

[0066] The switch unit control module 120 is used to control the contactor of the switch unit to be disconnected after the energy storage converter stops working, so as to disconnect the corresponding battery cluster from the energy storage converter.

[0067] It can be seen from the above embodiments that the above device establishes communication between the uninterruptible power supply and the battery management system. When the mains power is cut off, the uninterruptible power supply can promptly send a mains power abnormality signal to the battery management system, so that the battery management system shuts down the PCS and disconnects the switch unit after ensuring that both ends of the switch unit are not energized, thereby avoiding the phenomenon of forced disconnection of the switch unit contactor with power on, avoiding damage to the contactor, and ensuring the safe and stable operation of the energy storage system.

[0068] In a possible implementation, the energy storage converter control module 110 includes:

[0069] If the UPS battery abnormality signal sent by the uninterruptible power supply is not detected within a preset time interval after the mains abnormality signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after a first preset time.

[0070] In a possible implementation, the energy storage converter control module 110 includes:

[0071] If the abnormal mains power signal and the abnormal UPS battery signal sent by the uninterruptible power supply are monitored within a preset time interval, the energy storage converter is controlled to stop working.

[0072] In a possible implementation, the energy storage converter control module 110 includes:

[0073] If an abnormal mains power signal sent by the uninterruptible power supply is monitored, a stop signal is sent to the energy storage converter; the stop signal is used to instruct the energy storage converter to prohibit charging and discharging, and shut down after stopping charging and discharging.

[0074] In a possible implementation, the power-off control device 100 of the energy storage system further includes:

[0075] An abnormal signal transmission module, used for obtaining a UPS abnormal signal sent by the uninterruptible power supply through a dry contact after detecting a UPS abnormality;

[0076] The UPS abnormal signal includes a mains abnormal signal, a UPS fault signal and a UPS battery abnormal signal.

[0077] In a possible implementation, the energy storage system further includes an energy management system; the power-off control device 100 of the energy storage system further includes:

[0078] The abnormal signal display module is used to send the UPS abnormal signal to the energy management system so that the energy management system displays the UPS abnormal signal.

[0079] When the abnormal mains power signal sent by the uninterruptible power supply is monitored, controlling the energy storage converter to stop working comprises:

[0080] If no off-grid debugging signal is detected, then when no UPS battery abnormality signal sent by the uninterruptible power supply is detected within a preset time interval after the mains abnormality signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after a first preset time;

[0081] If an off-grid debugging signal is detected, when an abnormal mains power signal and an abnormal UPS battery signal sent by the uninterruptible power supply are detected within a preset time interval, the energy storage converter is controlled to stop working.

[0082] Figure 5 is a schematic diagram of a controller provided by an embodiment of the present invention. Figure 5 As shown, the controller 5 of this embodiment includes: a processor 50 and a memory 51. The memory 51 is used to store a computer program 52, and the processor 50 is used to call and run the computer program 52 stored in the memory 51 to perform the steps in the above-mentioned power-off control method embodiments of each energy storage system, such as Figure 2 Alternatively, the processor 50 is used to call and run the computer program 52 stored in the memory 51 to implement the functions of each module / unit in the above-mentioned device embodiments, for example Figure 4 The functions of the modules 110 to 120 are shown.

[0083] Exemplarily, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 52 in the controller 5. For example, the computer program 52 may be divided into Figure 4 Modules 110 to 120 are shown.

[0084] The controller 5 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The controller 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will appreciate that Figure 5 It is only an example of the controller 5 and does not constitute a limitation of the controller 5. The controller may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the controller may also include input and output devices, network access devices, buses, etc.

[0085] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0086] The memory 51 may be an internal storage unit of the controller 5, such as a hard disk or memory of the controller 5. The memory 51 may also be an external storage device of the controller 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the controller 5. Further, the memory 51 may include both an internal storage unit of the controller 5 and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the controller. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0087] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0088] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0089] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0090] In the embodiments provided by the present invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0091] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0092] In addition, each functional unit in each embodiment of the present invention 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.

[0093] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the power-off control method embodiments of the above-mentioned energy storage system can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0094] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A power-off control method for an energy storage system, characterized in that: The energy storage system includes an uninterruptible power supply, an energy storage converter, at least one battery module and a battery management system corresponding to each battery module; the battery module includes a switch unit and a battery cluster; each battery cluster is connected to one end of the corresponding switch unit, and the other end of each switch unit is connected to the DC end of the energy storage converter; the uninterruptible power supply is used to supply power to the auxiliary power supply of the energy storage system; The switch unit includes a contactor; The method is applied to the battery management system, comprising: When an abnormal mains power signal sent by the uninterruptible power supply is detected, controlling the energy storage converter to stop working; After the energy storage converter stops working, the contactor of the switch unit is controlled to be disconnected to disconnect the corresponding battery cluster from the energy storage converter.

2. The power-off control method of the energy storage system according to claim 1, characterized in that: When the abnormal mains power signal sent by the uninterruptible power supply is monitored, controlling the energy storage converter to stop working comprises: If the UPS battery abnormality signal sent by the uninterruptible power supply is not detected within a preset time interval after the mains abnormality signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after a first preset time.

3. The power-off control method of the energy storage system according to claim 1, characterized in that: When the abnormal mains power signal sent by the uninterruptible power supply is monitored, controlling the energy storage converter to stop working comprises: If the abnormal mains power signal and the abnormal UPS battery signal sent by the uninterruptible power supply are monitored within a preset time interval, the energy storage converter is controlled to stop working.

4. The power-off control method of the energy storage system according to claim 1, characterized in that: When the abnormal mains power signal sent by the uninterruptible power supply is monitored, controlling the energy storage converter to stop working comprises: If an abnormal mains power signal sent by the uninterruptible power supply is monitored, a stop signal is sent to the energy storage converter; the stop signal is used to instruct the energy storage converter to prohibit charging and discharging, and shut down after stopping charging and discharging.

5. The power-off control method of the energy storage system according to claim 1, characterized in that: Before controlling the energy storage converter to stop working when the abnormal mains power signal sent by the uninterruptible power supply is monitored, the method further includes: Acquire a UPS abnormality signal sent by the uninterruptible power supply through a dry contact after detecting a UPS abnormality; The UPS abnormal signal includes a mains abnormal signal, a UPS fault signal and a UPS battery abnormal signal.

6. The power-off control method of the energy storage system according to claim 5, characterized in that: The energy storage system also includes an energy management system; After obtaining the UPS abnormality signal sent by the uninterruptible power supply through the dry contact after detecting the UPS abnormality, the method further includes: The UPS abnormal signal is sent to the energy management system so that the energy management system displays the UPS abnormal signal.

7. The power-off control method of the energy storage system according to claim 2, characterized in that: When the abnormal mains power signal sent by the uninterruptible power supply is monitored, controlling the energy storage converter to stop working comprises: If no off-grid debugging signal is detected, then when no UPS battery abnormality signal sent by the uninterruptible power supply is detected within a preset time interval after the mains abnormality signal sent by the uninterruptible power supply is detected, the energy storage converter is controlled to stop working after a first preset time; If an off-grid debugging signal is detected, when an abnormal mains power signal and an abnormal UPS battery signal sent by the uninterruptible power supply are detected within a preset time interval, the energy storage converter is controlled to stop working.

8. A power-off control device for an energy storage system, characterized in that: The energy storage system includes an uninterruptible power supply, an energy storage converter, at least one battery module and a battery management system corresponding to each battery module; the battery module includes a switch unit and a battery cluster; each battery cluster is connected to one end of the corresponding switch unit, and the other end of each switch unit is connected to the DC end of the energy storage converter; the uninterruptible power supply is used to supply power to the auxiliary power supply of the energy storage system; The switch unit includes a contactor; The device is applied to the battery management system, comprising: An energy storage converter control module, used to control the energy storage converter to stop working when an abnormal mains power signal sent by the uninterruptible power supply is detected; The switch unit control module is used to control the contactor of the switch unit to disconnect after the energy storage converter stops working, so as to disconnect the corresponding battery cluster from the energy storage converter.

9. A controller, characterized in that: It comprises a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the power-off control method of the energy storage system according to any one of claims 1 to 7.

10. An energy storage system, characterized in that: Comprising a controller as claimed in claim 9.

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