Black start method of energy storage module and black start method of energy storage system

Abstract

The invention belongs to the field of energy storage systems, and relates to an energy storage module and a black-start method thereof, and an energy storage system and a black-start method thereof, and the black-start method of the energy storage module comprises the steps: controlling the energy storage module to enter a black-start mode after a controller and battery management units in N high-voltage boxes are powered on, and starting system fault detection, the system fault detection comprises the step of detecting the battery states of the N battery clusters; when no fault is detected in the system fault detection, controlling high voltages on the N battery clusters to supply power to the energy storage converter; and after detecting that the high voltage of the N battery clusters succeeds, controlling the energy storage converter to be started in an off-grid manner and establishing an alternating-current voltage. According to the method, various abnormities or faults occurring in the black start link can be eliminated in time, all the branch systems are matched with one another, each link is managed and controlled, it is ensured that the next link is executed after the current link is executed correctly, and the success rate of black start is greatly increased.

Description

Technical Field

[0001] The present application belongs to the field of energy storage systems, and specifically relates to an energy storage module and a black start method thereof, and an energy storage system and a black start method thereof. Background Art

[0002] Black start refers to the process in which, after the power system stops operating due to a fault, it starts the power supply with self-starting capability in the system, drives the power supply without self-starting capability, and restores its power generation capacity, and forms a small system in parallel with the black start power supply. Its goal is to achieve safe startup of the shut-down unit in the shortest time and provide power support for the subsequent recovery of the system.

[0003] Generally speaking, traditional black start power sources include hydropower stations and thermal power stations. However, due to geographical resource conditions, such as the scarcity of water resources in the northwest region, and the seasonality of water resources, there is often not enough water to support the black start of hydropower stations during the dry season in winter, so it is unlikely to choose hydropower units as black start power sources. At present, the country is vigorously developing new energy industries, such as photovoltaic power generation and energy storage. Using new energy for black start is a forward-looking and strategic solution, and it is less restricted by the environment and can become a reliable black start power source.

[0004] The existing black start method of photovoltaic energy storage field has a low success rate due to many reasons such as low coordination between various systems and failure to eliminate abnormalities or faults in various links in a timely manner. Summary of the invention

[0005] The embodiments of the present application provide an energy storage module and a black start method thereof, and an energy storage system and a black start method thereof, which can timely eliminate various abnormalities or faults occurring in the black start link and improve the success rate of the black start.

[0006] In a first aspect, an embodiment of the present application provides a black start method for an energy storage module, wherein the energy storage module includes N battery clusters, N high-voltage boxes, a controller, and an energy storage converter, each of the battery clusters is connected to the energy storage converter via one of the high-voltage boxes, the energy storage converter is connected to a power grid, the controller is connected to each of the high-voltage boxes, the high-voltage box includes a battery management unit, N is an integer ≥1, and the method includes:

[0007] After the controller and the battery management units in the N high-voltage boxes are powered on, the energy storage module is controlled to enter a black start mode, and system fault detection is started, wherein the system fault detection includes detecting the battery status of the N battery clusters;

[0008] When the system fault detection does not detect a fault, controlling the high voltage on the N battery clusters to supply power to the energy storage converter;

[0009] After detecting that the high voltage on the N battery clusters is successful, the energy storage converter is controlled to start off-grid and establish an AC voltage.

[0010] Optionally, after controlling the high voltage on the N battery clusters to power the energy storage converter, the method further includes:

[0011] After detecting that at least one of the N battery clusters fails to supply high voltage, other battery clusters that successfully supply high voltage are controlled to be powered off.

[0012] Optionally, the energy storage module further includes N black start switches, each of the high-voltage boxes and each of the battery clusters is connected to a black start switch, and before controlling the energy storage module to enter the black start mode, the steps include:

[0013] Closing the N black start switches powers on the controller and the battery management units in the N high-voltage boxes.

[0014] Optionally, the black start mode includes a first black start mode and a second black start mode, and controlling the energy storage module to enter the black start mode includes:

[0015] After detecting that the N black start switches are all in a closed state, controlling the energy storage module to enter a first black start mode; or,

[0016] After detecting that the UPS power supply flag is set, the energy storage module is controlled to enter the second black start mode.

[0017] Optionally, the controller establishes a communication connection with an energy management system, and after the startup system fault detection, before the controlling the high voltage on the N battery clusters to power the energy storage converter further includes:

[0018] When the system fault detection does not detect a fault, the controller updates the system state to a shutdown state, and when the system fault detection detects a fault, the controller updates the system state to a fault state;

[0019] The energy management system obtains the system state from the controller, and when the system state is a shutdown state, sends a black start command to the controller, so that after receiving the black start command, the controller controls the high voltage on the N battery clusters to power the energy storage inverter.

[0020] Optionally, the controller includes a container monitoring unit and a converter monitoring unit, the container monitoring unit is connected to each of the high-voltage boxes, and the converter monitoring unit is connected to the energy storage converter. The method specifically includes:

[0021] After the controller and the battery management units in the N high-voltage boxes are powered on, the container monitoring unit controls the energy storage module to enter a black start mode and starts system fault detection, wherein the system fault detection includes detecting the battery status of the N battery clusters;

[0022] When the system fault detection does not detect a fault, the container monitoring unit controls the high voltage on the N battery clusters to supply power to the energy storage converter;

[0023] After the container monitoring unit detects that the N battery clusters are successfully connected to high voltage, it sends a black start completion flag signal to the converter monitoring unit;

[0024] After receiving the black start completion flag signal, the converter monitoring unit controls the energy storage converter to start off-grid and establish an AC voltage.

[0025] In a second aspect, an embodiment of the present application provides a black start method for an energy storage system, wherein the energy storage system includes M energy storage modules connected in parallel, wherein M is an integer ≥ 1, and the method includes:

[0026] Controlling any one of the M energy storage modules to perform any one of the above-mentioned black start methods;

[0027] If it is detected that the establishment of the AC voltage is complete, the energy storage modules among the M energy storage modules that have not executed the black start method are controlled to execute normal startup.

[0028] In a third aspect, an embodiment of the present application provides an energy storage module, the energy storage module comprising N battery clusters, N high-voltage boxes, N black start switches, a controller and an energy storage converter, each of the battery clusters is connected to the energy storage converter via a high-voltage box, each of the high-voltage boxes and each of the battery clusters is connected to a black start switch, the energy storage converter is connected to a power grid, the controller is connected to each of the high-voltage boxes, the high-voltage box comprises a battery management unit, and N is an integer ≥1;

[0029] The controller includes: at least one processor and a memory communicatively connected to the at least one processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the at least one processor so that the at least one processor can execute any of the methods described above.

[0030] Optionally, the controller includes a container monitoring unit and a converter monitoring unit, wherein the container monitoring unit is connected to each of the high-voltage boxes, and the converter monitoring unit is connected to the energy storage converter.

[0031] The container monitoring unit is used to control the energy storage module to enter a black start mode and start system fault detection after the controller and the battery management units in the N high-voltage boxes are powered on. The system fault detection includes detecting the battery status of the N battery clusters. When the system fault detection does not detect a fault, the high voltage of the N battery clusters is controlled to power the energy storage inverter. After detecting that the high voltage of the N battery clusters is successfully supplied, a black start completion flag signal is sent to the inverter monitoring unit;

[0032] The converter monitoring unit is used to control the off-grid start of the energy storage converter and establish an AC voltage after receiving the black start completion flag signal.

[0033] In a fourth aspect, an embodiment of the present application provides an energy storage system, comprising M energy storage modules as described above, wherein M is an integer ≥1.

[0034] In an embodiment of the present application, a black start method for an energy storage module is provided, including controlling the energy storage module to enter a black start mode and starting a system fault detection after the controller and the battery management units in the N high-voltage boxes are powered on, wherein the system fault detection includes detecting the battery status of the N battery clusters; when the system fault detection does not detect a fault, controlling the high voltage on the N battery clusters to power the energy storage converter; after detecting that the high voltage on the N battery clusters is successful, controlling the energy storage converter to start off-grid and establish an AC voltage. The method of the present application can not only timely eliminate various abnormalities or faults that occur in the black start link, but also each branch system cooperates with each other to control each link, ensuring that the current link is executed correctly before executing the next link, which greatly improves the success rate of the black start. In addition, the black start method of the present application performs black start on all N battery clusters in the energy storage module at one time, rather than gradually performing black start on N battery clusters for multiple times, which can prevent the problems of excessive cluster current and uneven SOC (State of Charge, battery remaining power) between clusters during the start-up of a single cluster. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of the structure of an energy storage module is shown as an example;

[0036] Figure 2 A schematic diagram of the structure of a controller is shown as an example;

[0037] Figure 3 Another structural schematic diagram of an energy storage module is exemplarily shown;

[0038] Figure 4 An example is shown based on Figure 3 The communication architecture diagram of the energy storage module shown;

[0039] Figure 5A schematic structural diagram of the first high-voltage box A1 is exemplarily shown;

[0040] Figure 6 The example shows two Figure 1 A schematic structural diagram of an energy storage system of the energy storage module 100 shown;

[0041] Figure 7 The example shows two Figure 3 A schematic structural diagram of an energy storage system of the energy storage module 100 shown;

[0042] Figure 8 The example shows two Figure 1 Another structural schematic diagram of an energy storage system of the energy storage module 100 shown;

[0043] Fig. 9 A flow chart of a black start method of an energy storage module is exemplarily shown;

[0044] Fig.10 The flowchart of the black start method of the energy storage system is exemplified. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are 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.

[0046] It should be noted that the Figure 1 , Figure 3 as well as Figures 5 to 8 In the figure, a solid line connection indicates that there is a physical connection between two components (such as Figure 1 The energy storage converter 10 is connected with the first high-voltage box A1, the second high-voltage box A2 ... the Nth high-voltage box AN by a solid line), and the dotted line connection indicates that the two components are connected for communication (such as Figure 1 The controller 20 is connected with the first high-voltage tank A1, the second high-voltage tank A2...the Nth high-voltage tank AN by dotted lines).

[0047] See also Figure 1 , Figure 1 Schematically shows a structure of an energy storage module 100. Figure 1As shown, the energy storage module 100 includes N battery clusters, N high-voltage boxes, N black start switches, an energy storage converter 10 and a controller 20. Among them, the N battery clusters include a first battery cluster B1, a second battery cluster B2...Nth battery cluster BN. The N high-voltage boxes include a first high-voltage box A1, a second high-voltage box A2...Nth high-voltage box AN. The N black start switches include a first black start switch C1, a second black start switch C2...Nth black start switch CN.

[0048] Among them, each battery cluster is connected to the energy storage converter 10 through a high-voltage box, the energy storage converter 10 is connected to the power grid 200, each high-voltage box and each battery cluster are connected to a black start switch, the controller 20 is connected to each high-voltage box and the energy storage converter 10, and N is an integer ≥ 1. Specifically, the first battery cluster B1 is connected to the energy storage converter 10 through the first high-voltage box A1, the second battery cluster B2 is connected to the energy storage converter 10 through the second high-voltage box A2...the Nth battery cluster BN is connected to the energy storage converter 10 through the Nth high-voltage box AN. The first battery cluster B1 and the first high-voltage box A1 are both connected to the first black start switch C1, the second battery cluster B2 and the second high-voltage box A2 are both connected to the second black start switch C2...the Nth battery cluster BN and the Nth high-voltage box AN are both connected to the Nth black start switch CN. The controller 20 is connected to the first high-voltage box A1, the second high-voltage box A2...the Nth high-voltage box AN respectively.

[0049] The energy storage module 100 is a technical device that can convert electrical energy into chemical energy for storage, and then convert the stored energy into electrical energy to supply to a power grid or other power equipment when needed. In practical applications, one energy storage module 100 can correspond to one battery container.

[0050] The first black start switch C1, the second black start switch C2, ... the Nth black start switch CN are used to start the black start of the corresponding battery cluster. In some embodiments, the controller 20 and the battery management units in the N high-voltage boxes are powered on by closing the N black start switches.

[0051] The first high-voltage box A1, the second high-voltage box A2, ... the Nth high-voltage box AN may include a battery management unit for realizing functions such as battery cluster voltage / current acquisition, battery status calculation, contactor control and protection.

[0052] The energy storage converter (Power Conversion System, PCS) 10 can control the charging and discharging process of the battery, perform AC-DC conversion, and directly supply power to the AC load in the absence of a power grid. The energy storage converter is composed of a DC / AC bidirectional converter, etc. The energy storage converter 10 receives background control instructions through communication, and controls the converter to charge or discharge the battery cluster according to the sign and size of the power instruction, thereby adjusting the active power and reactive power of the power grid. The energy storage converter 10 communicates with each high-voltage box (including the first high-voltage box A1, the second high-voltage box A2...the Nth high-voltage box AN) and the controller 20 through a communication interface (CAN, 485, Ethernet, etc.) to obtain battery cluster status information, and can realize protective charging and discharging of the battery cluster to ensure the safe operation of the battery cluster. The energy storage converter 10 is also used for load connection to supply power to the load.

[0053] The controller 20 is respectively connected to the first high-voltage box A1, the second high-voltage box A2, ... the Nth high-voltage box AN and the energy storage converter 10. Specifically, the controller 20 can be a microcontroller unit (MCU) or a digital signal processing (DSP) controller.

[0054] The power grid 200 is also connected to the first high-voltage box A1, the second high-voltage box A2 ... the Nth high-voltage box AN respectively. Therefore, when the power grid 200 outputs voltage normally, the voltage output by the power grid 200 can supply power to the first high-voltage box A1, the second high-voltage box A2 ... the Nth high-voltage box AN after voltage transformation.

[0055] See also Figure 2 , Figure 2 20 is exemplarily shown. Figure 2 As shown, the controller 20 includes at least one processor 201 and a memory 202, wherein the memory 202 may be built in the controller 20 or externally located outside the controller 20, and the memory 202 may also be a remotely located memory connected to the controller 20 via a network.

[0056] The memory 202, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer executable programs and modules. The memory 202 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the terminal, etc. In addition, the memory 202 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 202 may optionally include a memory remotely arranged relative to the processor 201, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0057] The processor 201 performs various functions of the terminal and processes data by running or executing software programs and / or modules stored in the memory 202, and calling data stored in the memory 202, thereby monitoring the terminal as a whole, for example, implementing the black start method of the energy storage module described in any embodiment of the present application, and / or the black start method of the energy storage system.

[0058] The processor 201 may be one or more, Figure 2 A processor 201 is taken as an example. The processor 201 and the memory 202 may be connected via a bus or other means. The processor 201 may include a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, etc. The processor 201 may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0059] See also Figure 3 , Figure 3 Another structure of the energy storage module 100 is exemplarily shown. In this embodiment, the controller 20 includes a container monitoring unit 201 deployed on the battery container side and a converter monitoring unit 202 deployed on the energy storage converter side, wherein the container monitoring unit 201 is connected to each of the high-voltage boxes, and the converter monitoring unit 202 is connected to the energy storage converter 10.

[0060] It can be understood that the container monitoring unit 201 and the converter monitoring unit 202 can cooperate with each other to implement the black start method of the energy storage module described in any embodiment of the present application, and / or the black start method of the energy storage system. For example, the container monitoring unit 201 is used to control the energy storage module 100 to enter the black start mode and start the system fault detection after the container monitoring unit 201, the converter monitoring unit 202 and the battery management units in the N high-voltage boxes are powered on. When the system fault detection does not detect a fault, the high voltage on the N battery clusters is controlled to power the energy storage converter. After detecting that the high voltage on the N battery clusters is successful, a black start completion mark signal is sent to the converter monitoring unit 202. The converter monitoring unit 202 is used to control the energy storage converter 10 to start off-grid and establish an AC voltage after receiving the black start completion mark signal.

[0061] See also Figure 4 , Figure 4 An example is shown based on Figure 3 The communication architecture diagram of the energy storage module is shown in FIG. Figure 4 As shown, the container monitoring unit 201 is used to collect the telesignaling information and telemetering information in the battery container, report the telesignaling information and telemetering information in the battery container to the energy management system 101 (Energy Management System, referred to as EMS), and accept the scheduling of the energy management system 101. The converter monitoring unit 202 is used to collect the telesignaling information and telemetering information of the energy storage converter, report the telesignaling information and telemetering information on the energy storage converter side to the energy management system 101, and accept the scheduling of the energy management system 101. At the same time, the container monitoring unit 201 and the converter monitoring unit 202 also exchange information through communication. Among them, the telemetering information in the container is mainly battery-related information, such as SOC information, SOH (State Of Health, battery health status) information, battery temperature and container temperature; the telemetering information of the energy storage converter is mainly energy storage converter related information, such as power, voltage, current and power generation; the telesignaling information includes fault information, status information and alarm information on the battery container side or the energy storage converter side.

[0062] During the entire black start process, the energy management system 101 plays an overall coordination and control role. The container monitoring unit 201 and the converter monitoring unit 202 report the collected telesignaling information and telemetry information to the energy management system 101. The energy management system 101 controls each link of the black start execution process based on this information to ensure that the next link is executed only after the current link is executed correctly, which greatly improves the success rate of the black start.

[0063] Please refer to Figure 5 , Figure 5 A structure of the first high-voltage tank A1 is shown as an example.

[0064] In one embodiment, if Figure 5 As shown, the first high-voltage box A1 includes an upper high-voltage switch A11 . The upper high-voltage switch A11 is connected between the corresponding battery cluster (the first battery cluster B1 in this embodiment) and the energy storage converter 10 .

[0065] Specifically, the upper high-voltage switch A11 is configured to establish a connection between the first battery cluster B1 and the energy storage inverter 10 so that the first battery cluster B1 supplies power to the energy storage inverter 10; the upper high-voltage switch A11 is also configured to disconnect the connection between the first battery cluster B1 and the energy storage inverter 10 so that the first battery cluster B1 stops supplying power to the energy storage inverter 10.

[0066] In some embodiments, the upper high-voltage switch A11 is a controllable switch element such as a contactor or a relay.

[0067] In one embodiment, the first high-voltage box A1 further includes a DC conversion unit A12 and a first AC conversion unit.

[0068] The first DC / DC unit A12 is connected between the corresponding black start switch (the first black start switch C1 in this embodiment) and the controller 20. The first DC / DC unit A12 is used to supply power to the controller 20 based on the voltage output by the corresponding battery cluster (the first battery cluster B1 in this embodiment) when the corresponding black start switch (the first black start switch C1) is pressed.

[0069] The AC / DC unit A13 is connected between the power grid 200 and the controller 20. The AC / DC unit A13 is used to supply power to the controller 20 based on the power grid voltage (ie, the voltage output by the power grid 200).

[0070] In one embodiment, the first high voltage box A1 further includes a second AC-to-DC power supply A14 and a battery management unit A15.

[0071] The second AC-DC power supply A14 is connected between the power grid 200 and the battery management unit A15. The second AC-DC power supply A14 is used to supply power to the battery management unit A15 based on the power grid voltage. The battery management unit A15 is also respectively connected to the first black start switch C1 and the controller 20 to output a corresponding signal to the controller 20 when the first black start switch C1 is pressed, so that the controller 20 determines that the first black start switch C1 has been pressed. In some embodiments, the battery management unit A15 is configured as a battery management system (BMS) for monitoring, protecting and managing the first battery cluster B1.

[0072] Understandably, Figure 5 Only one structure of the first high-voltage box A1 is exemplarily shown, and the structures of other high-voltage boxes (such as the second high-voltage box A2) are the same as the first high-voltage box A1, which will not be described in detail here.

[0073] The embodiment of the present application further provides an energy storage system. The energy storage system includes M energy storage modules 100 in any embodiment of the present application, where M is an integer ≥1.

[0074] Figure 6 The example shows two Figure 1 A structure of an energy storage system of the energy storage module 100 is shown. The controllers 20 in the two energy storage modules 100 can implement the black start method of the energy storage module in any embodiment of the present application, and / or the black start method of the energy storage system.

[0075] Figure 7 The example shows two Figure 3 A structure of an energy storage system of the energy storage module 100 is shown. Among them, the container monitoring unit 201 and the converter monitoring unit 202 in the two energy storage modules 100 can cooperate to implement the black start method of the energy storage module in any embodiment of the present application, and / or the corresponding steps of the black start method of the energy storage system.

[0076] It should be noted that Figure 6-Figure 7 The hardware structure of the energy storage system 1 shown is only an example, and the energy storage system 1 may have more or fewer components than those shown in the figure, may combine two or more components, or may have different component configurations, and the various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application specific integrated circuits. For example, Figure 8 As shown, the energy storage system 1 also includes an energy management system 101. The energy management system 101 is respectively connected to the two controllers 20 for communication. In addition, the energy management system 101 is configured to schedule each controller 20 according to the telemetry information and telesignaling information fed back by each controller 20, so that each controller 20 executes the black start method of the energy storage module in any embodiment of the present application, and / or the black start method of the energy storage system.

[0077] Please refer to Fig. 9 , Fig. 9The flowchart of the black start method of the energy storage module is exemplified. The energy storage module includes N battery clusters, N high-voltage boxes, a controller and an energy storage inverter. Each battery cluster is connected to the energy storage inverter via a high-voltage box. The energy storage inverter is connected to the power grid. The controller is connected to each high-voltage box. The high-voltage box includes a battery management unit. N is an integer ≥ 1. Generally, the energy storage module also includes N black start switches, and each high-voltage box and each battery cluster are connected to a black start switch. In some embodiments, the energy storage module here can be connected as follows: Figure 1-Figure 5 The structural implementation shown and the specific implementation process have been described in detail in the above embodiments and will not be repeated here.

[0078] like Fig. 9 As shown, the black start method of the energy storage module includes:

[0079] Step S901, after the controller and the battery management units in the N high-voltage boxes are powered on, the energy storage module is controlled to enter a black start mode and system fault detection is started.

[0080] When the power grid fails and cannot supply power, the power supply of the control system in the energy storage module must be restored first, and then the black start of the energy storage module must be performed through the control system. In an embodiment, the controller and the battery management units in N high-voltage boxes can be powered on in two ways. The first way is to power on the controller and the battery management units in N high-voltage boxes by closing N black start switches; the second way is to use a UPS power supply to power on the controller and the battery management units in N high-voltage boxes. The first way requires manual stationing to manually close N black start switches, but no additional cost is required. The second way avoids the inconvenience of manually going to the station to close the black start switch, but it will increase additional costs.

[0081] When using UPS power supply for black start, after the power grid is out of power, the UPS power supply can immediately power on the controller and the battery management units in the N high-voltage boxes. In order to enable the controller to determine whether it is currently powered by UPS, a UPS power supply flag can be set in the energy management system to identify the current power supply method. The UPS power supply flag defaults to 0, that is, the UPS power supply is not used for power supply. When the second method is used for black start, the UPS power supply flag needs to be set to 1 before the first black start. When the controller detects that the UPS power supply flag is set, it can be determined that the black start mode has been entered.

[0082] The implementation methods of black start using UPS power supply and battery cluster are slightly different. In order to distinguish them, the black start mode is divided into the first black start mode and the second black start mode. Specifically, after the controller is powered on, the status of N black start switches is detected according to the number of battery clusters configured. If it is detected that all N black start switches are in the closed state, the energy storage module is controlled to enter the first black start mode; if it is detected that the UPS power supply flag is 1, the energy storage module is controlled to enter the second black start mode.

[0083] After entering the black start mode, the controller starts the system fault detection, which includes detecting the battery status of the N battery clusters and the powered-on control system (such as the controller). The battery status of the N battery clusters can be collected or calculated by the battery management unit in the N powered-on high-voltage boxes. To prevent interference, the system fault detection shields the fault detection items that cannot be detected in the current black start mode. Detecting the battery status of the N battery clusters and the powered-on control system before the black start can ensure that there are no faults in the system before the black start, thereby improving the success rate of the black start.

[0084] Specifically, in the first black start mode, except for the battery management unit and controller in the high-voltage box, other systems are not powered on. Therefore, in the first black start mode, the fault detection items shielded by the system fault detection include all faults related to dynamic environment equipment, where the dynamic environment equipment includes various types of equipment such as liquid cooling system, fire protection system, door magnet, water immersion sensor, etc. In the second black start mode, some dynamic environment equipment with lower power, such as sensors, door magnets, etc., can be powered by the UPS power supply, but some dynamic environment equipment with higher power, such as liquid cooling units, cannot be powered by the UPS power supply. Therefore, in the second black start mode, the fault detection items shielded by the system fault detection include faults related to various dynamic environment equipment that cannot be powered by the UPS power supply, such as liquid cooling loss fault.

[0085] Step S902: When the system fault detection does not detect a fault, the high voltage on the N battery clusters is controlled to supply power to the energy storage converter.

[0086] After the system fault detection is completed, if no fault is detected, the controller updates the system status to the shutdown status; if a fault is detected, the controller updates the system status to the fault status and reports the fault information to the energy management system. The energy management system outputs the fault information to the user so that the user can troubleshoot and eliminate the fault according to the fault information. At the same time, the controller performs a cyclic detection on the detected fault items, and after confirming that all faults have been eliminated, it updates the system status to the shutdown status.

[0087] The energy management system obtains the system status from the controller. When it detects that the system status is shutdown, it sends a black start command to the controller. After receiving the black start command, the controller controls the high voltage of N battery clusters to supply power to the energy storage converter. Figure 1 and Figure 5 For example, when the upper high-voltage switch A11 is closed, an electrical connection is established between the first battery cluster B1 and the energy storage inverter 10, and the first battery cluster B1 can supply power to the energy storage inverter 10. Conversely, when the upper high-voltage switch A11 is disconnected, the electrical connection between the first battery cluster B1 and the energy storage inverter 10 is disconnected, and the first battery cluster B1 stops supplying power to the energy storage inverter 10. After receiving the black start command, the controller 20 sends a power-on instruction to the battery management unit A15 of the N high-voltage boxes to control the upper high-voltage switch A11 in the high-voltage box to which it belongs to close to supply power to the energy storage inverter 10. It can be understood that the controller can also directly control the N high-voltage boxes to close their internal upper high-voltage switches after updating the system status to the shutdown state without waiting for the black start command sent by the energy management system.

[0088] In the first black start mode, in order to prevent the black start switch from being disconnected during the closing process of the upper high-voltage switch in the high-voltage box, during the process of N high-voltage boxes closing their internal upper high-voltage switches in turn, the controller detects in real time whether the N black start switches are all in a closed state. If at least one black start switch is detected to be in a disconnected state, the black start process is terminated, and the other battery clusters that have successfully closed the high voltage are controlled to power off, that is, the high-voltage box that has successfully closed the upper high-voltage switch is controlled to disconnect its internal upper high-voltage switch, thereby avoiding SOC imbalance between different battery clusters or even excessive voltage difference.

[0089] Step S903, after detecting that the N battery clusters have successfully reached high voltage, the energy storage converter is controlled to start off-grid and establish an AC voltage.

[0090] In the process of N high-voltage boxes closing their internal upper high-voltage switches in sequence, the controller detects in real time whether the upper high-voltage switches in the N high-voltage boxes are closed successfully. If it is detected that all the upper high-voltage switches in the N high-voltage boxes are closed, it is determined that the N battery clusters are successfully connected to high voltage; if it is detected that the upper high-voltage switch in at least one of the N high-voltage boxes fails to close, it is determined that the N battery clusters fail to connect to high voltage. At this time, in order to avoid SOC imbalance between different battery clusters, the other battery clusters that have successfully connected to high voltage are controlled to power off, that is, the other high-voltage boxes that have successfully closed their upper high-voltage switches are controlled to disconnect their internal upper high-voltage switches.

[0091] After the high voltage is successfully applied to N battery clusters, the DC bus of the energy storage inverter is powered, and the controller controls the energy storage inverter to start off-grid and establish AC voltage. Specifically, the controller controls the energy storage inverter to operate in voltage source mode, and gradually starts slowly to the preset AC voltage. When the controller detects that the voltage value output by the energy storage inverter reaches the preset AC voltage, it determines that the AC voltage is established. After determining that the AC voltage is established, it delays for a period of time, exits the black start mode, and restores all shielded fault detection items. At this point, the black start process of the energy storage module is realized.

[0092] In some embodiments, the controller includes a container monitoring unit and a converter monitoring unit, wherein the container monitoring unit is connected to each high-voltage box, and the converter monitoring unit is connected to the energy storage converter. Figure 3 As shown, the controller 20 includes a container monitoring unit 201 and a converter monitoring unit 202 . The container monitoring unit 201 is also connected to each high-voltage box, and the converter monitoring unit 202 is also connected to the energy storage converter 10 .

[0093] At this time, in step S901, after the battery management units in the controller and N high-voltage boxes are powered on, the specific implementation process of controlling the energy storage module to enter the black start mode and starting the system fault detection includes the following steps: after the battery management units in the controller and N high-voltage boxes are powered on, the container monitoring unit controls the energy storage module to enter the black start mode and starts the system fault detection.

[0094] At this time, in step S902, when the system fault detection does not detect a fault, the specific implementation process of controlling the high voltage on the N battery clusters to power the energy storage converter includes the following steps: when the system fault detection does not detect a fault, the container monitoring unit controls the high voltage on the N battery clusters to power the energy storage converter. In one embodiment, when the system fault detection does not detect a fault, the container monitoring unit updates the system state to a shutdown state, and when the system fault detection detects a fault, the container monitoring unit updates the system state to a fault state; the energy management system obtains the system state from the container monitoring unit, and when the system state is a shutdown state, sends a black start command to the container monitoring unit; after receiving the black start command, the container monitoring unit controls the high voltage on the N battery clusters to power the energy storage converter.

[0095] At this time, after the high voltage of N battery clusters is detected in step S903, the specific implementation process of controlling the off-grid startup of the energy storage inverter and establishing the AC voltage includes the following steps: after the container monitoring unit detects that the high voltage of N battery clusters is successful, it sends a black start completion signal to the inverter monitoring unit; after the inverter monitoring unit receives the black start completion signal, it controls the off-grid startup of the energy storage inverter and establishes the AC voltage. Figure 3As shown, after the container monitoring unit 201 detects that the upper high-voltage switches inside the N high-voltage boxes are all closed successfully, it sends a black start completion mark signal to the converter monitoring unit 202; after the converter monitoring unit 202 receives the black start completion mark signal, it controls the energy storage converter 10 to start off-grid and establish AC voltage.

[0096] Furthermore, the converter monitoring unit detects the voltage value output by the energy storage converter. When the voltage value reaches the preset AC voltage, it determines that the AC voltage is established and sends an AC voltage establishment completion signal to the container monitoring unit. After receiving the AC voltage establishment completion signal, the container monitoring unit delays for a period of time, exits the black start mode, and restores all blocked fault detection items.

[0097] The black start method of the energy storage module provided in the present application, on the one hand, powers on the battery management units in N high-voltage boxes, collects the battery status information of N battery clusters through the battery management units in the N high-voltage boxes, and starts the system fault detection before the black start to detect the battery status and control system of the N battery clusters, ensuring that the battery clusters and control systems used for the black start have no faults; on the other hand, during the black start execution process, each system cooperates with each other to control each link, ensuring that the next link is executed only after the current link is executed correctly, which greatly improves the success rate of the black start. In addition, the black start method of the present application performs black start on all N battery clusters in the energy storage module at one time, rather than gradually performing black start on N battery clusters multiple times, which can prevent problems such as excessive cluster current and uneven SOC between clusters during the start of a single cluster.

[0098] See also Fig.10 , Fig.10 The flowchart of the black start method of the energy storage system is shown as an example. The energy storage system includes M energy storage modules connected in parallel, where M is an integer ≥ 1. In some embodiments, the energy storage system can be Figure 6-Figure 8 The structural implementation shown and the specific implementation process have been described in detail in the above embodiments and will not be repeated here.

[0099] like Fig.10 As shown, the black start method of the energy storage system includes the following method steps:

[0100] Step S1001: Control any energy storage module among the M energy storage modules to execute the black start method of the energy storage module in any embodiment of the present application.

[0101] Step S1002: If it is detected that the AC voltage is established, the energy storage modules among the M energy storage modules that have not executed the black start method are controlled to execute normal startup.

[0102] Specifically, the M energy storage modules include a first energy storage module, a second energy storage module, ... an Mth energy storage module. One energy storage module (assuming it is the first energy storage module) is selected from the M energy storage modules to execute Fig. 9 The black start method shown in the figure, the energy storage converter in the first energy storage module can output an AC voltage as a voltage source. After the AC voltage is established, the AC voltage can power the high-voltage boxes of other energy storage modules (including the second energy storage module to the Mth energy storage module) in the M energy storage modules to power on the other energy storage modules.

[0103] In one embodiment, after the controller or converter monitoring unit of the energy storage module that completes the black start detects that the AC voltage is established, the system state is updated to running. After the energy management system detects that the system state is running, it sends a startup instruction to the controllers or container monitoring units of other energy storage modules, so that other energy storage modules perform normal startup. At this point, the black start of the energy storage system is completed.

[0104] The present application also provides a non-volatile computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors, for example, to execute the above-described Fig. 9 and Fig.10 method steps.

[0105] The present application also provides a computer program product, including a computer program stored on a non-volatile computer-readable storage medium, wherein the computer program includes program instructions, and when the program instructions are executed by a computer, the computer executes the black start method of the energy storage module in any of the above method embodiments, and / or the black start method of the energy storage system, for example, executing the above described Fig. 9 and Fig.10 method steps.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Under the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes in different aspects of the present application as described above, which are not provided in detail for the sake of simplicity. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A black start method for an energy storage module, characterized in that: The energy storage module includes N battery clusters, N high-voltage boxes, a controller and an energy storage converter, each of the battery clusters is connected to the energy storage converter via one of the high-voltage boxes, the energy storage converter is connected to the power grid, the controller is connected to each of the high-voltage boxes, the high-voltage box includes a battery management unit, and N is an integer ≥1; The method comprises: After the controller and the battery management units in the N high-voltage boxes are powered on, the energy storage module is controlled to enter a black start mode, and system fault detection is started, wherein the system fault detection includes detecting the battery status of the N battery clusters; When the system fault detection does not detect a fault, controlling the high voltage on the N battery clusters to supply power to the energy storage converter; After detecting that the high voltage on the N battery clusters is successful, the energy storage converter is controlled to start off-grid and establish an AC voltage.

2. The method according to claim 1, characterized in that After controlling the high voltage on the N battery clusters to supply power to the energy storage converter, the method further includes: After detecting that at least one of the N battery clusters fails to supply high voltage, other battery clusters that successfully supply high voltage are controlled to be powered off.

3. The method according to claim 1, characterized in that The energy storage module further includes N black start switches, each of the high voltage box and each of the battery clusters is connected to a black start switch, and the control of the energy storage module entering the black start mode includes: Closing the N black start switches powers on the controller and the battery management units in the N high-voltage boxes.

4. The method according to claim 3, characterized in that The black start mode includes a first black start mode and a second black start mode, and controlling the energy storage module to enter the black start mode includes: After detecting that the N black start switches are all in a closed state, controlling the energy storage module to enter a first black start mode; or, After detecting that the UPS power supply flag is set, the energy storage module is controlled to enter the second black start mode.

5. The method according to any one of claims 1 to 4, characterized in that: The controller establishes a communication connection with the energy management system, and after the startup system fault detection, before the high voltage on the N battery clusters is controlled to supply power to the energy storage converter, it also includes: When the system fault detection does not detect a fault, the controller updates the system state to a shutdown state, and when the system fault detection detects a fault, the controller updates the system state to a fault state; The energy management system obtains the system state from the controller, and when the system state is a shutdown state, sends a black start command to the controller, so that after receiving the black start command, the controller controls the high voltage on the N battery clusters to power the energy storage inverter.

6. The method according to any one of claims 1 to 4, characterized in that: The controller includes a container monitoring unit and a converter monitoring unit, the container monitoring unit is connected to each of the high-voltage boxes, the converter monitoring unit is connected to the energy storage converter, and the method specifically includes: After the controller and the battery management units in the N high-voltage boxes are powered on, the container monitoring unit controls the energy storage module to enter a black start mode and starts system fault detection, wherein the system fault detection includes detecting the battery status of the N battery clusters; When the system fault detection does not detect a fault, the container monitoring unit controls the high voltage on the N battery clusters to supply power to the energy storage converter; After the container monitoring unit detects that the N battery clusters are successfully connected to high voltage, it sends a black start completion flag signal to the converter monitoring unit; After receiving the black start completion flag signal, the converter monitoring unit controls the energy storage converter to start off-grid and establish an AC voltage.

7. A black start method for an energy storage system, characterized in that: The energy storage system comprises M energy storage modules connected in parallel, wherein M is an integer ≥ 1, and the method comprises: Controlling any one of the M energy storage modules to perform the black start method according to any one of claims 1 to 6; If it is detected that the establishment of the AC voltage is complete, the energy storage modules among the M energy storage modules that have not executed the black start method are controlled to execute normal startup.

8. An energy storage module, characterized in that: The energy storage module includes N battery clusters, N high-voltage boxes, N black start switches, a controller and an energy storage converter, each of the battery clusters is connected to the energy storage converter via a high-voltage box, each of the high-voltage boxes and each of the battery clusters is connected to a black start switch, the energy storage converter is connected to a power grid, the controller is connected to each of the high-voltage boxes, and the high-voltage box includes a battery management unit, and N is an integer ≥1; The controller includes: at least one processor and a memory communicatively connected to the at least one processor, the memory storing instructions executable by the at least one processor, the instructions being executed by the at least one processor so that the at least one processor can execute the method described in any one of claims 1 to 7.

9. The energy storage module according to claim 8, characterized in that: The controller includes a container monitoring unit and a converter monitoring unit, wherein the container monitoring unit is connected to each of the high-voltage boxes, and the converter monitoring unit is connected to the energy storage converter. The container monitoring unit is used to control the energy storage module to enter a black start mode and start system fault detection after the controller and the battery management units in the N high-voltage boxes are powered on. The system fault detection includes detecting the battery status of the N battery clusters. When the system fault detection does not detect a fault, the high voltage of the N battery clusters is controlled to power the energy storage inverter. After detecting that the high voltage of the N battery clusters is successfully supplied, a black start completion flag signal is sent to the inverter monitoring unit; The converter monitoring unit is used to control the off-grid start of the energy storage converter and establish an AC voltage after receiving the black start completion flag signal.

10. An energy storage system, characterized in that: The method comprises M energy storage modules as claimed in claim 8 or 9, wherein M is an integer ≥1.

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