Battery assembly and energy storage system

Abstract

The invention provides a battery assembly and an energy storage system. The battery assembly includes a control unit and a DC-DC converter. And the control unit is used for controlling the DC-DC converter to output a first current when the first load is short-circuited in the process that the battery assembly supplies power to the first load, and the first current is larger than the maximum nominal discharge current of the battery assembly, is used for disconnecting the electric connection between the first load and the bus and is smaller than the short-circuit protection current of the battery assembly. And / or the control unit is used for controlling the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly after the power supply is powered down, and supplying power to the first load and the second load through the DC-DC converter; after the first load is powered off, the discharging capacity of the battery assembly is controlled to be recovered to the maximum nominal discharging capacity, and power is supplied to the second load through the DC-DC converter. Therefore, the crash of the energy storage system comprising the battery assembly is avoided.

Description

[0001] This application is a divisional application. The application number of the original application is 202080018443.7, and the original application date is July 16, 2020. The entire contents of the original application are incorporated into this application by reference. Technical Field

[0002] The present application relates to the field of energy technology, and in particular to a battery assembly and an energy storage system. Background Art

[0003] Lead-acid batteries, lithium batteries and other battery components are widely used in various power backup scenarios. However, in actual applications, there are often load short circuits and / or power outages, which can easily cause system downtime. Summary of the invention

[0004] The present application provides a battery assembly and an energy storage system to solve the problem of energy storage system downtime caused by load short circuit and / or power failure of the power supply. On the one hand, the battery assembly has a short-circuit current limiting output characteristic when the load is short-circuited, and can output a discharge current with an amplitude greater than the maximum nominal discharge current of the battery assembly and less than the short-circuit protection current of the battery assembly, so that the load is disconnected from the energy storage system before the battery assembly, and the busbar voltage in the energy storage system can be automatically restored. On the other hand, the battery assembly has a short-term overload discharge capability after the power supply is lost, and can improve the discharge capacity of the battery assembly during the time period from the power supply failure to the secondary load power failure, so that the battery assembly supplies power to important loads and secondary loads at the same time, ensuring that the energy storage system will not be down, and can also restore the maximum nominal discharge capacity of the battery assembly after the power supply is lost to the secondary load power failure, so that the battery assembly supplies power to important loads, ensuring the backup power time of important loads.

[0005] In a first aspect, the present application provides a battery assembly, including: a control unit and a DC-DC converter.

[0006] A control unit is used to control the DC-DC converter to output a first current when the first load is short-circuited during the process of the battery assembly supplying power to the first load. The first current is greater than the maximum nominal discharge current of the battery assembly, used to disconnect the electrical connection between the first load and the bus, and is less than the short-circuit protection current of the battery assembly; the maximum nominal discharge current of the battery assembly is the maximum current allowed when the battery assembly is normally discharged, and the short-circuit protection current of the battery assembly is the current that can disconnect the electrical connection between the battery assembly and the bus.

[0007] The battery assembly provided by the first aspect has a short-circuit current limiting output characteristic. Specifically, the battery assembly can continue to perform current limiting work when any load is short-circuited. The amplitude of the discharge current output by the battery assembly is greater than the maximum nominal discharge current of the battery assembly and less than the short-circuit protection current of the battery assembly. Moreover, the discharge current duration of the battery assembly is stable and controllable. Therefore, when any load is short-circuited, the short-circuited load will be disconnected from the energy storage system before the battery assembly, and the busbar voltage in the energy storage system can be automatically restored.

[0008] In a possible design, the battery assembly also includes: a battery pack; a first end of a DC-DC converter is electrically connected to the positive electrode of the battery pack, a second end of the DC-DC converter is electrically connected to the negative electrode of the battery pack, a third end of the DC-DC converter is electrically connected to the first bus, a fourth end of the DC-DC converter is electrically connected to the second bus, a fifth end of the DC-DC converter is electrically connected to the control unit, the first bus and the second bus are used to provide direct current, and a first load is electrically connected in parallel between the first bus and the second bus; a control unit is specifically used to control the DC-DC converter to reduce the equivalent loop impedance of the battery assembly based on the third pulse width of the first signal when the first load is short-circuited, so as to control the discharge current of the battery assembly to be the first current; wherein the first signal represents the duty cycle of the power switch tube in the DC-DC converter, and the pulse width of the first signal is used to adjust the equivalent loop impedance of the battery assembly to control the discharge current of the battery assembly. Thus, the control unit in the battery assembly controls the duty cycle of the power switch tube in the DC-DC converter so that the discharge current output by the battery assembly is the first current, providing a possible implementation method for the battery assembly to output the first current.

[0009] In a possible design, the control unit is also specifically used to monitor the port voltage of the battery assembly in the discharge state; and when the port voltage of the battery assembly in the discharge state is less than or equal to the first preset voltage, it is determined that the first load is short-circuited, and the battery assembly is controlled to output the first current. Thus, the control unit in the battery assembly can determine whether the load is short-circuited based on the port voltage of the battery assembly in the discharge state, so as to timely control the discharge current output by the DC-DC converter to be the first current. Thus, the control unit can determine whether the load is short-circuited, so as to timely control the discharge current output by the DC-DC converter to be the first current.

[0010] In a second aspect, the present application provides a battery assembly, including: a control unit and a DC-DC converter.

[0011] A control unit is used to control the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly after the power supply source is powered off, and to supply power to a first load and a second load through a DC-DC converter; after the first load is powered off, control the discharge capacity of the battery assembly to be restored to the maximum nominal discharge capacity, and to supply power to the second load through a DC-DC converter; wherein the power supply source is used to provide direct current to the first load and the second load before the power supply source is powered off, and the second load is powered before the first load.

[0012] Through the battery assembly provided by the second aspect, the monitoring unit in the energy storage system controls the power-off of the secondary load with the help of the power-off alarm signal to ensure the backup power duration of the important load. And the battery assembly has a short-term overload discharge capability. Specifically, the discharge capacity (such as discharge power or discharge current) of the battery assembly is greater than the maximum nominal discharge capacity (such as maximum nominal discharge power or maximum nominal discharge current) of the battery assembly during the time period from the power supply failure to the power-off of the secondary load, and the discharge capacity (such as discharge power or discharge current) of the battery assembly is stable and controllable. Thus, during the time period from the power supply failure to the power-off of the secondary load, the battery assembly supplies power to the important load and the secondary load at the same time, ensuring that the energy storage system will not experience station downtime. After the power supply fails to the power supply of the secondary load, the discharge capacity (such as discharge power or discharge current) of the battery assembly is restored to the maximum nominal discharge capacity (such as maximum nominal discharge power or maximum nominal discharge current) of the battery assembly, so that the battery assembly supplies power to the important load, ensuring the backup power duration of the important load.

[0013] In a possible design, when the discharge capacity of the battery assembly is characterized by the discharge power of the battery assembly, the control unit is used to control the discharge power of the battery assembly to be greater than the maximum nominal discharge power during the period from the power supply failure to the first load power-on after the power supply fails, and the maximum nominal discharge power is the maximum power allowed during normal discharge of the battery assembly; after the first load is powered off, the battery assembly is controlled to restore the maximum nominal discharge power. Therefore, the battery assembly uses the discharge power to characterize the discharge capacity of the battery assembly, thereby providing a possible implementation method for adjusting the discharge capacity of the battery assembly.

[0014] or,

[0015] When the discharge capacity of the battery assembly is characterized by the discharge current of the battery assembly, the control unit is used to control the discharge current of the battery assembly to be greater than the maximum nominal discharge current during the period from the power failure of the power supply to the first load power-on after the power supply source is powered off, and the maximum nominal discharge current is the maximum current allowed during normal discharge of the battery assembly; after the first load is powered off, the battery assembly is controlled to restore the maximum nominal discharge current. Therefore, the battery assembly uses the discharge current to characterize the discharge capacity of the battery assembly, thereby providing another possible implementation method for adjusting the discharge capacity of the battery assembly.

[0016] In one possible design, the first load is used to implement 5G data services, and the second load is used for voice services and transmission services other than 5G data services.

[0017] In a possible design, the control unit is further configured to control the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly when the port voltage of the battery assembly is less than or equal to the second preset voltage in the charging state or the standby state. Thus, the control unit can determine whether the power supply source is powered off, so as to improve the discharge capacity of the battery assembly in a timely manner.

[0018] In one possible design, the battery assembly also includes: a battery pack; a first end of the DC-DC converter is electrically connected to the positive electrode of the battery pack, a second end of the DC-DC converter is electrically connected to the negative electrode of the battery pack, a third end of the DC-DC converter is electrically connected to the first bus, a fourth end of the DC-DC converter is electrically connected to the second bus, and a fifth end of the DC-DC converter is electrically connected to the control unit, the first bus and the second bus are used to provide direct current through a power supply, and the first load and the second load are electrically connected in parallel between the first bus and the second bus; the control unit is specifically used to control the DC-DC converter to reduce the equivalent loop impedance of the battery assembly based on the first pulse width of the first signal to control the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly; after a preset time, based on the second pulse width of the first signal, control the DC-DC converter to increase the equivalent loop impedance of the battery assembly to control the discharge capacity of the battery assembly to return to the maximum nominal discharge capacity of the battery assembly; wherein the first pulse width is greater than or equal to the second pulse width, and the pulse width of the first signal is used to adjust the equivalent loop impedance of the battery assembly to control the discharge power or discharge current of the battery assembly. Therefore, the control unit in the battery assembly changes the discharge capacity of the battery assembly by controlling the duty cycle of the power switch tube in the DC-DC converter, thereby providing a possible implementation method for adjusting the discharge capacity of the battery assembly.

[0019] In a third aspect, the present application provides an energy storage system, comprising: a power supply component, a first busbar, a second busbar, and a battery component in the first aspect and any possible design of the first aspect; and / or, a power supply component, a first busbar, a second busbar, and a battery component in the second aspect and any possible design of the second aspect.

[0020] In a possible design, the energy storage system further includes: a monitoring unit, the monitoring unit is electrically connected to the power supply assembly; the power supply assembly is used to send a power failure alarm signal to the monitoring unit after the power supply source fails; the monitoring unit is also used to control the secondary loads in the power load to power off when receiving the power failure alarm signal. As a result, the monitoring unit can promptly control the secondary loads to power off when the power supply source fails, so that the battery assembly does not need to have a long-term overload discharge capacity to avoid damage to the battery assembly.

[0021] In one possible design, the energy storage system includes any of the following: a data center, a communication site, or an energy storage power station.

[0022] The beneficial effects of the energy storage system provided in the third aspect and each possible design of the third aspect can refer to the beneficial effects brought about by the first aspect and each possible implementation method of the first aspect, and / or, the beneficial effects can refer to the beneficial effects brought about by the second aspect and each possible implementation method of the second aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the structure of an energy storage system provided in one embodiment of the present application;

[0024] Figure 2A A schematic diagram of the structure of a battery assembly provided in one embodiment of the present application;

[0025] Figure 2B It is a structural schematic diagram of an existing lithium battery;

[0026] Figure 3 A timing diagram of short-circuit current limiting output of a battery assembly provided in an embodiment of the present application;

[0027] Figure 4A A schematic diagram of the timing from charging to discharging of a battery assembly provided in an embodiment of the present application;

[0028] Figure 4B An external characteristic curve diagram of voltage U-current I of a battery assembly provided in one embodiment of the present application;

[0029] Figure 4C This is an external characteristic curve diagram of voltage U-current I of a battery assembly provided in one embodiment of the present application.

[0030] Description of reference numerals:

[0031] 10—Energy storage system; 20—Electric load; 30—Power supply;

[0032] 11—power supply assembly; W1—first busbar; W2—second busbar; 12—battery assembly; 13—battery shunt; K1—BLVD contactor; K2—switch module; 21—first load; 22—second load; 14—monitoring unit; 15—load shunt; K3—LLVD contactor; K41 and K42—load circuit breakers; 121—battery cell pack; 122—DC-DC converter; 123—control unit; 1231—sampling module; 1232—adjustment module; 1233—BMS;

[0033] 200—bidirectional switch; 300—charger; 400—controller. DETAILED DESCRIPTION

[0034] The present application provides a battery assembly and energy storage system, which can be applied to various backup power scenarios such as communication sites, data centers, and energy storage power stations. On the one hand, the battery assembly has a short-circuit current limiting output characteristic. Specifically, the battery assembly can continue to limit current when any load is short-circuited. The amplitude of the discharge current output by the battery assembly is greater than the maximum nominal discharge current of the battery assembly and less than the short-circuit protection current of the battery assembly. The discharge current duration of the battery assembly is stable and controllable, so that when any load is short-circuited, the short-circuited load will be disconnected from the energy storage system before the battery assembly, and the busbar voltage in the energy storage system can be automatically restored.

[0035] On the other hand, the monitoring unit in the energy storage system uses the power-off alarm signal to control the power-off of the secondary load to ensure the backup power duration of the important load. The battery assembly has a short-term overload discharge capability. Specifically, the discharge capability (such as discharge power or discharge current) of the battery assembly is greater than the maximum nominal discharge capability (such as maximum nominal discharge power or maximum nominal discharge current) of the battery assembly during the time period from the power supply failure to the power-off of the secondary load, and the discharge capability (such as discharge power or discharge current) of the battery assembly is stable and controllable. Thus, during the time period from the power supply failure to the power-off of the secondary load, the battery assembly supplies power to the important load and the secondary load at the same time, ensuring that the energy storage system will not experience station downtime. After the power supply failure to the power-off of the secondary load, the discharge capability (such as discharge power or discharge current) of the battery assembly is restored to the maximum nominal discharge capability (such as maximum nominal discharge power or maximum nominal discharge current) of the battery assembly, so that the battery assembly supplies power to the important load, ensuring the backup power duration of the important load.

[0036] Among them, whether the load is powered first can be set based on the importance of the load's business. Generally, the higher the importance of the business, the corresponding load will be powered first, that is, the important load is powered first over the secondary load. In addition, this application does not limit the specific types of secondary loads and important loads.

[0037] Below, in conjunction with specific embodiments, specific implementations of the battery assembly 12 and the energy storage system 10 of the present application are described in detail.

[0038] Figure 1 FIG. 1 shows a schematic diagram of the structure of an energy storage system provided by an embodiment of the present application. Figure 1 As shown, the energy storage system 10 of the present application may include: a power supply component 11, a first busbar W1, a second busbar W2, and at least one battery component 12. The present application does not limit the specific implementation of the energy storage system 10. In some embodiments, the energy storage system 10 may include any of the following: a data center, a communication site, or an energy storage power station.

[0039] The first busbar W1 and the second busbar W2 are used to provide direct current. Among them, the busbar voltage in the energy storage system 10 is the voltage between the first busbar W1 and the second busbar W2. The battery assembly 12 can be electrically connected in parallel between the first busbar W1 and the second busbar W2, so that the battery assembly 12 can be charged or discharged. And the power load 20 is also electrically connected in parallel between the first busbar W1 and the second busbar W2, so that the power load 20 can obtain electrical energy. It should be noted that in this application, the electrical connection between the battery assembly 12 and the busbar is disconnected by taking the electrical connection between the battery assembly 12 and the second busbar W2 as an example, and the electrical connection between the power load 20 and the busbar is disconnected by taking the electrical connection between the power load 20 and the second busbar W2 as an example.

[0040] The present application does not limit the number and specific implementation structure of the battery assembly 12. When the number of battery assemblies 12 is greater than 1, continue to combine Figure 1 The energy storage system 10 may also include: a battery shunt 13 and a battery low voltage down (BLVD) contactor K1. In addition, when the battery assembly 12 is electrically connected in parallel between the first busbar W1 and the second busbar W2, the present application usually adds a switch module K2 between the battery assembly 12 and the second busbar W2 to protect the battery assembly 12. For ease of explanation, Figure 1 Two battery assemblies 12 are used for illustration, and each battery assembly 12 is electrically connected to the second busbar W2 through the switch module K2 via the BLVD contactor K1 and the battery shunt 13.

[0041] Next, combine Figure 2A The specific implementation structure of the battery assembly 12 of the present application is introduced. It should be noted that: Figure 2A The switch module K2, the battery shunt 13 and the BLVD contactor K1 are not shown in the figure.

[0042] Figure 2AFIG. 1 shows a schematic diagram of the structure of a battery assembly provided by an embodiment of the present application. Figure 2A As shown, the battery assembly 12 of the present application may include: a battery cell pack 121 , a DC-DC converter 122 (direct current-direct current converter) and a control unit 123 .

[0043] The first end 1 of the DC-DC converter 122 is electrically connected to the positive pole (+) of the battery cell pack 121, the second end 2 of the DC-DC converter 122 is electrically connected to the negative pole (-) of the battery cell pack 121, the third end 3 of the DC-DC converter 122 is electrically connected to the first bus W1, the fourth end 4 of the DC-DC converter 122 is electrically connected to the second bus W2, and the fifth end 5 of the DC-DC converter 122 is electrically connected to the control unit 123.

[0044] Among them, the present application does not limit the specific implementation of the battery pack 121. In some embodiments, the battery pack 121 may include: at least one battery cell. When the battery pack 121 includes multiple battery cells, the multiple battery cells are electrically connected in series; or, the multiple battery cells are electrically connected in parallel; or, the multiple battery cells are electrically connected in series and in parallel. In addition, the present application does not limit the specific type of battery cell. For example, the type of battery cell may be a lithium battery.

[0045] The present application does not limit the specific implementation of the DC-DC converter 122. In some embodiments, the DC-DC converter 122 may include any one of the following: a buck conversion circuit (Buck circuit), a boost conversion circuit (Boost circuit), a buck-boost conversion circuit (Buck-Boost circuit), a flyback circuit, a forward circuit, a half-bridge topology, a full-bridge topology, and an isolated or non-isolated circuit composed of at least one of the foregoing topologies.

[0046] Among them, the control unit 123 can be an integrated chip, such as a microcontroller unit (MCU) or a system on a chip (SoC), or it can be a combination of multiple components, or it can be a combination of an integrated chip and peripheral circuits, which is not limited in this application.

[0047] In some embodiments, the control unit 123 may include: a sampling module 1231 , an adjustment module 1232 , and a battery management system (BMS) 1233 .

[0048] The sampling module 1231 is used to collect the discharge current of the battery assembly 12, and collect the port voltage of the battery assembly 12 (i.e., the voltage between the third terminal 3 and the fourth terminal 4 of the DC-DC converter 122) based on the first busbar W1 and the second busbar W2. The sampling module 1231 sends the discharge current and port voltage of the battery assembly 12 to the adjustment module 1232. The port voltage of the battery assembly 12 may include: the port voltage of the battery assembly 12 in the discharge state, and the port voltage of the battery assembly 12 in the charging state or the standby state.

[0049] The adjustment module 1232 is used to determine whether the power load 20 is short-circuited based on the port voltage of the battery assembly 12 in the discharge state and the first preset voltage, and determine that the power load 20 is short-circuited when the port voltage of the battery assembly 12 in the discharge state is less than or equal to the first preset voltage. The first preset voltage can be configured based on the length of the line between the battery assembly 12 and the second busbar W2.

[0050] The adjustment module 1232 is further configured to obtain the first signal based on the discharge current of the battery assembly 12, or to obtain the first signal based on the discharge current of the battery assembly 12 and the port voltage of the battery assembly 12 in the discharge state. For example, the adjustment module 1232 obtains the first signal through single-loop or multi-loop proportional-integral-derivative control (PID control). The adjustment module 1232 outputs the first signal to the DC-DC converter 122.

[0051] The first signal represents the duty cycle of the power switch tube in the DC-DC converter 122, and the first signal is used to adjust the equivalent loop impedance of the battery assembly 12 to achieve the purpose of controlling the discharge power or discharge current of the battery assembly 12. The present application does not limit the specific implementation method of the first signal. For example, the first signal can be a pulse width modulation (PWM) signal, etc.

[0052] The adjustment module 1232 is also used to determine whether the power supply source 30 has lost power based on the port voltage of the battery assembly 12 in the charging state or the standby state, so that the battery assembly 12 determines whether to charge, standby or discharge. For example, the adjustment module 1232 can pre-configure a second preset voltage. Among them, the specific size of the second preset voltage is not limited in this application. In general, the second preset voltage will be slightly smaller than the port voltage of the battery assembly 12 in the charging state or the standby state. When the port voltage of the battery assembly 12 in the charging state or the standby state is less than or equal to the second preset voltage, the adjustment module 1232 can determine that the power supply source 30 has lost power, so that the battery assembly 12 can be converted from the charging state or the standby state to the discharging state. Among them, the charging state can be understood as a floating charge state or an equalized charge state, and the standby state can be understood as the charging channel of the battery assembly 12 is disconnected and the discharging channel of the battery assembly 12 is opened, that is, the battery assembly 12 cannot be charged and can be discharged.

[0053] The BMS 1233 is used to manage the chargeable and dischargeable capacity of the battery pack 121 and other battery management functions. The BMS 1233 can be implemented by software algorithms and / or hardware circuits.

[0054] Based on the above description, the control unit 123 can determine whether the electrical load 20 is short-circuited based on the port voltage of the battery assembly 12 in the discharge state and the first preset voltage, and determine that the electrical load 20 is short-circuited when it is determined that the port voltage of the battery assembly 12 in the discharge state is less than or equal to the first preset voltage. Therefore, the control unit 123 can control the DC-DC converter 122 to adjust the equivalent loop impedance of the battery assembly 12 based on the first signal, so that the discharge current of the battery assembly 12 changes.

[0055] Furthermore, the control unit 123 can determine whether the power supply source 30 is powered off based on the port voltage of the battery assembly 12 in the charging state or the standby state and the second preset voltage, so that the battery assembly 12 determines whether to charge or standby or discharge, and when the port voltage of the battery assembly 12 in the charging state or the standby state is less than or equal to the second preset voltage, the control unit 30 determines that the power supply source 30 is powered off, and the battery assembly 12 can be switched from the charging state or the standby state to the discharging state. Thus, the control unit 123 can control the DC-DC converter 122 to adjust the equivalent loop impedance of the battery assembly 12 based on the first signal, so that the discharge power or discharge current of the battery assembly 12 changes.

[0056] Generally, the larger the pulse width of the first signal, the smaller the equivalent loop impedance of the battery assembly 12, and the greater the discharge power or discharge current of the battery assembly 12. The smaller the pulse width of the first signal, the larger the equivalent loop impedance of the battery assembly 12, and the smaller the discharge power and discharge current of the battery assembly 12.

[0057] It should be noted that the battery assembly 12 is not limited to the above implementation.

[0058] The present application does not limit the number and type of the electrical load 20. When the number of secondary loads in the electrical load 20 is greater than 1, continue to combine Figure 1 The energy storage system 10 may also include: a load shunt 15 and a load low voltage down (LLVD) contactor K3. In addition, when the power load 20 is electrically connected in parallel between the first bus W1 and the second bus W2, the present application usually adds a load circuit breaker (K41 and K42) between the power load 20 and the second bus W2.

[0059] In some embodiments, when the electrical load 20 includes the first load 21, the first end of the first load 21 is electrically connected to the first bus W1, and the second end of the first load 21 is electrically connected to the second bus W2 via the load circuit breaker K41 of the first load 21. The load circuit breaker K41 of the first load 21 can be used to prevent overcurrent of the first load 21 when a short circuit occurs.

[0060] In other embodiments, when the power load 20 includes a first load 21 and a second load 22, the second load 22 is powered before the first load 21. That is, the first load 21 is a secondary load, and the second load 22 is an important load. In some embodiments, the first load 21 is used to implement 5G data services, and the second load 22 is used for voice services and transmission services other than 5G data services, such as 2G / 3G / 4G services. It should be noted that the first load 21 involved here is a secondary load and the second load 22 is an important load is only an example, and the present application does not limit the specific types of the first load 21 and the second load 22.

[0061] For ease of explanation, Figure 1 In the figure, one important load and two secondary loads, namely, one second load 22 and two first loads 21 are used for illustration. The two first loads 21 are electrically connected to the second bus W2 through the load circuit breaker K41 via the LLVD contactor K3 and the load diverter 15, and the second load 22 is electrically connected to the second bus W2 through the load circuit breaker K42 via the LLVD contactor K3 and the load diverter 15. The power supply source 30 provides direct current to the second bus W2 through the power supply component 11, and the power supply component 11 can also monitor the status of the power supply source 30. Among them, the specific implementation method of the power supply component 11 is not limited in this application.

[0062] In some embodiments, the power supply component 11 may be composed of a rectifier unit. The input end of the rectifier unit is electrically connected to the power supply 30 (i.e., the AC power supply), the output ground terminal of the rectifier unit is electrically connected to the first bus W1, and the output power supply end of the rectifier unit is electrically connected to the second bus W2. The rectifier unit converts the AC power provided by the power supply 30 into DC power, and the rectifier unit provides DC power to the second bus W2. The present application does not limit the specific implementation method of the rectifier unit. For example, the rectifier unit includes a rectifier circuit and a filter circuit. And the power supply 30 can be an energy source such as wind energy.

[0063] In other embodiments, the power supply component 11 may also be composed of a DC-DC power converter. The input end of the DC-DC power converter is electrically connected to the power supply 30 (i.e., a DC power supply), the output ground terminal of the DC-DC power converter is electrically connected to the first bus W1, the output power supply end of the DC-DC power converter is electrically connected to the second bus W2, and the DC-DC power converter provides direct current to the second bus W2. The present application does not limit the specific implementation of the DC-DC power converter. The power supply 30 may be energy sources such as high voltage direct current (HVDC) and solar panels.

[0064] In addition, the energy storage system 10 of the present application may further include: a monitoring unit 14. The monitoring unit 14 is electrically connected to the power supply assembly 11, and the monitoring unit 14 is also electrically connected to the control end of the LLVD contactor K3 and the BLVD contactor K1. In addition, the monitoring unit 14 can obtain electrical energy by being electrically connected in parallel between the first busbar W1 and the second busbar W2, so as to realize the normal operation of the monitoring unit 14.

[0065] When the power supply source 30 loses power, the power supply component 11 can send a power failure alarm signal to the monitoring unit 14, so that the monitoring unit 14 controls the LLVD contactor K3 to disconnect, so that the secondary load (i.e., the first load 21) is disconnected from the energy storage system 10. The specific representation form of the power failure alarm signal is not limited in this application.

[0066] In actual application, after the power supply source 30 loses power, the battery assembly is required to supply power to the power load 20 so that the power load 20 can maintain operation. For example, the power load 20 includes the first load 21 mentioned above. When the battery assembly supplies power to the first load 21, the battery assembly, the first busbar W1, the second busbar W2 and the first load 21 can form a loop.

[0067] When the battery assembly uses an existing lead-acid battery, if the first load 21 is short-circuited, the existing lead-acid battery will output a discharge current of several hundred to several thousand amperes, and the discharge current is uncontrollable, which will bring safety hazards to the entire energy storage system. Therefore, the existing lead-acid battery must be equipped with an expensive DC fuse (that is, the switch module K2 uses a DC fuse), and then the tripping current threshold and time difference of the DC fuse and the load switch K41 corresponding to the first load 21 are used to achieve short-circuit hierarchical protection, but the cost of the DC fuse is high and the volume is large.

[0068] When the battery components use existing lithium batteries, such as Figure 2B As shown, the existing lithium battery may include: a battery pack 121, a bidirectional switch 200, a charger 300 and a controller 400. The first end of the battery pack 121 is electrically connected to the second busbar W2 via the bidirectional switch 200, and the second end of the battery pack 121 is electrically connected to the first busbar W1. The charger 300 is electrically connected in parallel to both sides of the bidirectional switch 200.

[0069] It should be noted that Figure 2B It is only a feasible connection method between the existing lithium battery and the first busbar W1 and the second busbar W2 respectively. Other modules may be included between the existing lithium battery and the first busbar W1 and / or the existing lithium battery and the second busbar W2, and this application does not limit this.

[0070] If the first load 21 is short-circuited, the bidirectional switch 200 will cut off the circuit when the discharge current output by the existing lithium battery reaches a certain threshold. The bidirectional switch 200 may include but is not limited to: a contactor, a relay or two power semiconductor devices (such as a bidirectional MOS tube) connected in series.

[0071] Since the current in the loop is uncontrollable and the duration is short (usually a few hundred microseconds), and it can be understood that the load circuit breaker K41 of the first load 21 is usually a mechanical switch. If the bidirectional switch 200 in the existing lithium battery uses a bidirectional MOS tube, the bidirectional MOS tube is an electronic switch, and the sensitivity of the electronic switch is higher than that of the mechanical switch, that is, the mechanical switch will trip after a delay of a period of time, and the electronic switch will be disconnected immediately after receiving the corresponding instruction. Therefore, the existing lithium battery may protect itself in advance, and will disconnect the electrical connection with the second bus W2 before the first load 21, causing the risk of the busbar voltage in the energy storage system 10 being dragged to death by the short-circuited first load 21, causing the energy storage system 10 to shut down. If the bidirectional switch 200 uses a contactor or relay, when the first load 21 is short-circuited, the contactor or relay is forcibly tripped under the short-circuit current, which will seriously damage the contacts in the contactor or relay, and even cause the contacts in the contactor or relay to melt and stick.

[0072] It can be seen that the use of existing lead-acid batteries or existing lithium batteries will cause certain safety risks and system downtime risks when a load short circuit occurs.

[0073] When the battery assembly adopts the battery assembly 12 of the present application, the present application is provided with a first current greater than the maximum nominal discharge current of the battery assembly 12 and less than the short-circuit protection current of the battery assembly 12, and the first current is the discharge current output by the battery assembly 12 when the first load 21 is short-circuited. Among them, the maximum nominal discharge current of the battery assembly 12 is the maximum current allowed when the battery assembly 12 is normally discharged, and the short-circuit protection current of the battery assembly 12 is the current that can disconnect the electrical connection between the battery assembly 12 and the second bus W2. In the present application, the second current is the current that disconnects the electrical connection between the first load 21 and the second bus W2, that is, the tripping current threshold of the load circuit breaker K41 of the first load 21. It can be understood by those skilled in the art that the second current is usually less than or equal to the maximum nominal current of the battery assembly 12. Therefore, the first current is greater than the second current.

[0074] Among them, the present application does not limit the specific sizes of the first current, the second current, the short-circuit protection current of the battery assembly 12, and the maximum nominal discharge current of the battery assembly 12. In some embodiments, for scenarios with large loads, when configuring the capacity of the load circuit breaker (K41 or K42), the tripping current threshold will be close to or even exceed the maximum nominal discharge current of the battery assembly 12. The capacity of the load circuit breaker here refers to the maximum current allowed to pass through the load switch when the load circuit breaker is not tripped. For example, the first current can be set to be greater than 50% of the maximum nominal discharge current of the battery assembly 12, and the second current can be set to be greater than 25%-30% of the maximum nominal discharge current of the battery assembly 12.

[0075] Based on the above configuration, the battery assembly 12 of the present application has a short-circuit current limiting output characteristic, that is, when a short circuit occurs in the load, the amplitude of the first current output by the battery assembly 12 of the present application is greater than the maximum nominal discharge current amplitude of the battery assembly 12 and less than the amplitude of the short-circuit protection current of the battery assembly 12, so that the duration of the first current output by the battery assembly 12 of the present application is stable and controllable, so that the first load 21 is electrically disconnected from the second bus W2 before the battery assembly 12 of the present application, so that the busbar voltage in the energy storage system 10 can be automatically restored, thereby avoiding the risk of station downtime of the energy storage system 10.

[0076] In some embodiments, the battery assembly 12 can determine whether the first load 21 is short-circuited based on the port voltage of the battery assembly 12 in the discharge state and the first preset voltage. When the port voltage of the battery assembly 12 in the discharge state is less than or equal to the first preset voltage, it can be determined that the first load 21 is short-circuited. If the first load 21 is short-circuited, then since the first current is set to be greater than the maximum nominal discharge current of the battery assembly 12 and less than the short-circuit protection current of the battery assembly 12, the battery assembly 12 can control the DC-DC converter 122 to adjust the equivalent loop impedance of the battery assembly 12 to be smaller based on the first signal, so that the discharge current of the battery assembly 12 becomes larger. Thus, the battery assembly 12 can output a first current with a stable and controllable amplitude and duration, and the first current is greater than the second current, so that the first load 21 will be disconnected from the second bus W2 before the battery assembly 12. As a result, the short-circuited first load 21 is disconnected from the energy storage system 10, allowing the busbar voltage in the energy storage system 10 to automatically recover.

[0077] In some embodiments, when a short circuit occurs in the first load 21, the control unit 123 in the battery assembly 12 may increase the pulse width of the first signal (i.e., the third pulse width) so that the equivalent loop impedance of the battery assembly 12 decreases, thereby increasing the first current output by the battery assembly 12, and the first current output by the battery assembly 12 is greater than the maximum nominal current of the battery assembly 12.

[0078] The third pulse width of the first signal may be set according to the maximum nominal current of the battery assembly 12 and the second current.

[0079] In some embodiments, the second current is a tripping current threshold of the load circuit breaker K41 of the first load 21. Thus, the first load 21 is automatically disconnected by the load circuit breaker K41 of the first load 21, that is, the load circuit breaker K41 of the first load 21 is tripped, so that the first load 21 is electrically disconnected from the second bus W2, thereby disconnecting the first load 21 from the energy storage system 10, and the DC-DC converter 122 can continue to be electrically connected to the second bus W2, ensuring that the battery assembly 12 can continue to supply power to other loads in the power load 20.

[0080] Next, combine Figure 3 , examples are given to illustrate the changes in the discharge current of the existing lead-acid battery, the existing lithium battery and the battery assembly 12 of the present application.

[0081] Figure 3 A timing diagram of short-circuit current limiting output of a battery assembly provided in an embodiment of the present application is shown. Figure 3In the figure, the horizontal axis is time t, and the vertical axis is current I. Curve 1 represents the curve of the discharge current of the existing lead-acid battery changing with time when the first load 21 is short-circuited, curve 2 represents the curve of the discharge current of the existing lithium battery changing with time when the first load 21 is short-circuited, and curve 3 represents the curve of the discharge current of the battery assembly 12 of the present application changing with time when the first load 21 is short-circuited.

[0082] like Figure 3 As shown, the first load 21 is short-circuited at time t1, so that the discharge current of the existing lead-acid battery, the discharge current of the existing lithium battery, and the discharge current of the battery assembly 12 of the present application are all increased after time t1. For the battery assembly 12 of the present application, at time t2, the DC-DC converter 122 will output the first current I3, so that the amplitude of the first current I3 of the battery assembly 12 of the present application is greater than the maximum nominal discharge current of the battery assembly 12 and less than the amplitude of the short-circuit protection current of the battery assembly 12, and the duration of the first current I3 remains stable and controllable. The first current I3 is greater than the second current, so that the load switch K41 of the first load 21 is automatically tripped, so that the busbar voltage in the energy storage system is automatically restored. For the existing lithium battery, at time t3, the bidirectional switch will quickly cut off the electrical connection between the existing lithium battery and the second busbar W2, so that the discharge current of the existing lithium battery becomes zero, causing the existing lithium battery to lock, causing the energy storage system to shut down. For the existing lead-acid battery, at time t4, the DC fuse will disconnect the electrical connection between the existing lead-acid battery and the second busbar W2, so that the discharge current of the existing lead-acid battery becomes zero.

[0083] Therefore, compared with curve 1, the battery assembly 12 of the present application can automatically limit the current when the first load 21 is short-circuited, and within the safety range, there is no need to equip the existing lead-acid battery with an expensive DC fuse. Compared with curve 2, the battery assembly 12 of the present application solves the problem of the energy storage system being shut down due to the locking of the existing lithium battery when the first load 21 is short-circuited. There is no need to manually restore the normal operation of the battery assembly 12, or manually remove the short-circuited first load 21, thereby reducing maintenance costs.

[0084] Therefore, in the present application, based on the precise coordination between the battery assembly 12 and the power load 20, the power load 20 is disconnected from the busbar voltage in the energy storage system 10 before the battery assembly 12 after a short circuit. In addition, the amplitude and duration of the short-circuit discharge current of the battery assembly 12 can be configured by the user, which increases the flexibility of the energy storage system 10.

[0085] In actual application scenarios, in addition to the risk of downtime caused by load short circuit, power failure of the power supply will also affect the backup power reliability of the energy storage system. Existing energy storage systems often support 5G data services and 2G / 3G / 4G voice and transmission services at the same time. Take the power load 20 as an example, including the first load 21 and the second load 22 mentioned above. Among them, the second load 22 is powered before the first load 21, that is, the first load 21 is a secondary load, and the second load 22 is an important load. That is, the battery assembly of the existing energy storage system is in a charging state or a standby state. When the power supply 30 loses power, the battery assembly will switch from the charging state or the standby state to the discharging state, and the battery assembly will supply power to the power load 20, and at the same time supply power to the first load 21 and the second load 22.

[0086] In the prior art, if the power supply source 30 loses power, the monitoring unit in the existing energy storage system usually controls the secondary loads to power off first, and then controls the important loads to power off, thereby ensuring that the backup power time of the important loads can be extended under the configuration of lower battery capacity through staged power off.

[0087] The specific implementation process includes: after the power supply source 30 loses power, the existing battery assembly in the existing energy storage system supplies power to the important load and the secondary load at the same time, and the monitoring unit detects the busbar voltage in real time. When the busbar voltage decreases to the LLVD power-off voltage as the discharge time increases, the monitoring unit in the existing energy storage system controls the secondary load to power off until the busbar voltage reaches the BLVD power-off voltage, and the monitoring unit in the existing energy storage system controls the BLVD contactor K1 to operate, disconnecting the existing battery assembly from the existing energy storage system.

[0088] Since battery components are usually expensive, in many scenarios, the existing energy storage system only needs to configure the capacity of the existing battery components according to the current I2 of the important load and the backup power duration T11 (i.e., I2*T11). Under this configuration condition, the initial discharge rate after the power supply is powered off is IL / (I2*T11), where IL is the sum of the current I2 of the important load and the current I1 of the secondary load. If IL is much larger than I2, the actual discharge rate of the existing battery components (rate = current / capacity) will be very large. At this time, the following two problems will arise:

[0089] Problem 1: The polarization characteristics of existing battery components are very serious. The port voltage of existing battery components drops rapidly, and the effect of graded power-off is not ideal.

[0090] Question 2: If the actual discharge rate of the existing battery assembly is much greater than 1C, the existing battery assembly will have overcurrent protection, causing the existing battery assembly to automatically protect itself and disconnect from the existing energy storage system, causing the existing energy storage system to shut down.

[0091] In the present application, when the power supply source 30 loses power, the power supply component 11 of the present application can send a power failure alarm signal to the monitoring unit 14. When the monitoring unit 14 receives the power failure alarm signal, it controls the LLVD contactor K3 to disconnect, so that the first load 21 is powered off. And the battery component 12 of the present application switches from the charging state or the standby state to the discharging state after determining that the power supply source 30 loses power, so that the battery component 12 of the present application supplies power to the power load 20.

[0092] Since the port voltage of the battery assembly 12 will drop rapidly as the power supply source 30 loses power, the battery assembly 12 of the present application can determine whether the power supply source 30 loses power by the port voltage of the battery assembly 12 in the charging state or the standby state. For example, the control unit 123 in the battery assembly 12 can determine the magnitude of the port voltage of the battery assembly 12 in the charging state or the standby state and the second preset voltage to determine whether the power supply source 30 loses power, and further control the battery assembly 12 to switch from the charging state or the standby state to the discharging state. For example, when the port voltage of the battery assembly 12 in the charging state or the standby state is less than or equal to the second preset voltage, the battery assembly 12 of the present application can determine that the power supply source 30 loses power, so that the battery assembly 12 of the present application switches from the charging state or the standby state to the discharging state.

[0093] Since there is a certain delay in the monitoring unit 14 controlling the LLVD contactor K3 to disconnect, the present application sets the discharge capacity (i.e., discharge power or discharge current) of the battery assembly 12 during the time period from the power failure of the power supply source 30 to the power failure of the first load 21 to be greater than the maximum nominal discharge capacity (i.e., maximum nominal discharge power or maximum nominal discharge current). Among them, the maximum nominal discharge power of the battery assembly 12 is the maximum power allowed when the battery assembly 12 is discharged normally. After the first load 21 is powered off, the discharge capacity of the battery assembly 12 is restored to the maximum nominal discharge capacity, that is, before the power supply source 30 is powered off, the discharge capacity of the battery assembly 12 is the maximum nominal discharge capacity.

[0094] In some embodiments, the battery assembly 12 of the present application adjusts the equivalent loop impedance of the battery assembly 12 based on the first signal, so that the discharge power of the battery assembly 12 during the time period from when the power supply source 30 is powered off to when the first load 21 is powered off is greater than the maximum nominal discharge power of the battery assembly 12, and also enables the battery assembly 12 to restore the maximum nominal discharge power after the first load 21 is powered off. The actual discharge power of the battery assembly 12 depends on the load amount of the important load.

[0095] Alternatively, the battery assembly 12 of the present application adjusts the equivalent loop impedance of the battery assembly 12 based on the first signal, so that the discharge current of the battery assembly 12 during the time period from when the power supply source 30 is powered off to when the first load 21 is powered off is greater than the maximum nominal discharge current of the battery assembly 12, and also enables the battery assembly 12 to restore the maximum nominal discharge current after the first load 21 is powered off. The actual discharge current of the battery assembly 12 depends on the load amount of the important load.

[0096] In some embodiments, when the battery assembly 12 of the present application is switched from a charging state or a standby state to a discharging state, the control unit 123 in the battery assembly 12 may increase the pulse width of the first signal (i.e., the first pulse width) so that the equivalent loop impedance of the battery assembly 12 becomes smaller, thereby increasing the discharge power or discharge current of the battery assembly 12. After a preset time, the battery assembly 12 of the present application may decrease the pulse width of the first signal (i.e., the second pulse width) so that the equivalent loop impedance of the battery assembly 12 becomes larger, thereby decreasing the discharge power or discharge current of the battery assembly 12, that is, the battery assembly 12 restores the maximum nominal discharge power, or the battery assembly 12 restores the maximum nominal discharge current, so as to restore the normal operation of the battery assembly 12. Wherein, the first pulse width is greater than the second pulse width.

[0097] Among them, the starting moment of the preset duration is the moment when the battery assembly 12 switches from the charging state or the standby state to the discharging state. This application does not limit the specific size of the preset duration. Among them, this application can control the discharge capacity of the DC-DC converter 122 in the battery assembly 12 according to the power of the total load. Thereby, the discharge capacity (i.e., discharge power or discharge current) of the battery assembly 12 of this application can support the total load. On this basis, this application can configure the backup capacity of the battery assembly 12 only according to the power (or current) of the important load and the backup time.

[0098] Compared with the prior art, in the present application, when a power failure occurs in the power supply source 30, the monitoring unit 14 controls the power-off of the secondary load by monitoring the power-off alarm signal. There is no need to collect the busbar voltage to control the order of graded power-off, nor is there any need to rely on the setting of the two power-off voltage parameters LLVD and BLVD. This avoids the influence of the polarization characteristics of the existing battery components under high-rate discharge on the effect of graded power-off, and also avoids the triggering of overcurrent protection action by the existing battery components under short-term high-rate discharge.

[0099] After the battery assembly 12 is switched from the charging state or the standby state to the discharging state, the discharge capacity in the time period before the secondary load is powered off is improved, and power can be supplied to the important load and the secondary load at the same time, ensuring that the energy storage system 10 of the present application does not lose power and avoiding the phenomenon of the energy storage system shutting down. After the secondary load is powered off, the discharge capacity of the battery assembly 12 is restored to the maximum nominal discharge capacity, and the battery assembly 12 only provides backup power for the important load. Therefore, with a smaller capacity configuration of the battery assembly 12 of the present application, the backup power duration of the important load is basically unaffected.

[0100] Take the first load 21 as a secondary load and the second load 22 as an important load as an example. In the time period from when the power supply 30 is powered off to when the first load 21 is powered off, the battery assembly 12 has a short-term overload discharge capability, so that the battery assembly 12 supplies power to the first load 21 and the second load 22, supporting the total load in the energy storage system 10 of the present application, and avoiding the phenomenon of the energy storage system shutting down. After the first load 21 is powered off, the battery assembly 12 supplies power to the second load 22, ensuring the backup power time of the important load. Thereby, the capacity configuration of the battery assembly 12 in the energy storage system 10 of the present application is saved, the number of battery assemblies 12 in the energy storage system 10 is reduced, and the cost is reduced.

[0101] Next, combine Figure 4A-4C , the specific working process of the battery assembly 12 of the present application after the power supply 30 is powered off is illustrated by way of example.

[0102] Figure 4A A timing diagram of a battery assembly from charging to discharging provided in an embodiment of the present application is shown. Figure 4A In the figure, the horizontal axis is time t and the vertical axis is current I.

[0103] like Figure 4A As shown, in the time period 0-t1, the battery assembly 12 is in a charging state, that is, the curve of the battery assembly 12 in the charging state can be curve 1 or curve 2. Among them, curve 1 represents that the battery assembly 12 is in a floating charge state, and curve 2 represents that the battery assembly 12 is in an equalized charge state. At time t1, the power supply 30 loses power. At this time, the battery assembly 12 supplies power to the first load 21 and the second load 22, and the discharge current of the battery assembly 12 is I1+I2. At time t2, that is, after the T1 time period, the first load 21 is disconnected from the energy storage system 10, and the battery assembly 12 supplies power to the second load 22, and the discharge current of the battery assembly 12 becomes I2. Among them, I1 is the discharge current of the battery assembly 12 to the first load 21, and I2 is the discharge current of the battery assembly 12 to the second load 22.

[0104] Therefore, the battery assembly 12 has a short-term overload discharge capability in the T1 time period, and the discharge power (or discharge current) of the battery assembly 12 is greater than the discharge power (or discharge current) of the battery assembly 12 after time t2, and the discharge power (or discharge current) of the battery assembly 12 in the T1 time period is stable and controllable. The discharge capacity of the battery assembly 12 after time t2 is restored to the maximum nominal discharge capacity, so that the battery assembly 12 continues to supply power according to the normal discharge power (or discharge current).

[0105] Figure 4B-4C An external characteristic curve diagram of voltage U-current I in a battery assembly provided in an embodiment of the present application is shown. Figure 4B-4C In the figure, the horizontal axis is the current I and the vertical axis is the voltage V.

[0106] The working modes of the battery assembly 12 may include: Figure 4B The battery assembly 12 is in any of the constant voltage mode, constant power mode or constant current mode shown. When the battery assembly 12 is in the constant voltage mode, the DC-DC converter 122 can ensure that the battery assembly 12 can output a constant voltage. The working modes of the battery assembly 12 can also include: Figure 4C The working mode of the simulated real battery is shown, that is, the terminal voltage gradually decreases with the extension of discharge time.

[0107] Curve 1 represents a battery assembly 12 that only has a short-time overload discharge capability. Curve 2 represents a battery assembly 12 that has both a short-circuit current limiting output characteristic and a short-time overload discharge capability.

[0108] Continue to combine Figure 4B and Figure 4C Regardless of which working mode the battery assembly 12 is in, after the power supply 30 is powered off, during the period from the power supply 30 being powered off to the first load 21 being powered off, the voltage U-current I external characteristic curve of the battery assembly 12 changes from curve 1 to curve 2. Thus, the battery assembly 12 has a short-term overload discharge capability, and the battery assembly 12 supplies power to the first load 21 and the second load 22. After the first load 21 is powered off, the battery assembly 12 supplies power to the second load 22.

[0109] In addition, when the port voltage of the battery assembly 12 in the discharge state drops to the voltage V1 (i.e., the first preset voltage), the battery assembly 12 can determine that the first load 21 is short-circuited. Therefore, based on the first signal, the battery assembly 12 controls the amplitude of the discharge current of the battery assembly 12 below the V1 operating point to be greater than the maximum nominal discharge current above the V1 operating point and less than the short-circuit protection current of the battery assembly 12, and the amplitude and duration of the discharge current of the battery assembly 12 below the V1 operating point are both stable and controllable, that is, the current of the battery assembly 12 is increased from the current I4 to the current I3 (i.e., the first current). Among them, the current I4 is the maximum nominal discharge current of the battery assembly 12 when it is working normally.

[0110] In summary, the battery assembly of the present application can not only have the short-circuit current limiting output characteristic, but also have the short-time overload discharge capability. It should be noted that the battery assembly of the present application can only have the short-circuit current limiting output characteristic, can only have the short-time overload discharge capability, or can have both the short-circuit current limiting output characteristic and the short-time overload discharge capability.

[0111] Exemplarily, the present application further provides a user device. The device of the present application may include: an electric load 20 and an energy storage system 10 .

[0112] The present application does not limit the specific implementation of the user equipment.

[0113] The power supply 30 is used to supply power to the energy storage system 10 and the electrical load 20. The energy storage system 10 supplies power to the electrical load 20 to ensure the normal operation of the electrical equipment. The electrical load 20 may include a transceiver device, which is used to receive or send signals. In addition, the electrical equipment of the present application may also include a control device, which may control the transceiver device to receive or send signals.

[0114] The electrical equipment of this application can be used to perform Figure 1-4C The technical solution of the illustrated embodiment has similar implementation principles and technical effects, wherein the implementation operations of each module may be further described with reference to the relevant description of the method embodiment, which will not be repeated here.

[0115] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A battery assembly, characterized in that: include: Control unit and DC-DC converter, The control unit is used to control the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly after the power supply source is powered off, and supply power to the first load and the second load through the DC-DC converter; after the first load is powered off, control the discharge capacity of the battery assembly to be restored to the maximum nominal discharge capacity, and supply power to the second load through the DC-DC converter; The power supply is used to provide direct current to the first load and the second load before the power supply is powered off, and the second load is powered before the first load.

2. The battery assembly according to claim 1, characterized in that: When the discharge capacity of the battery assembly is characterized by the discharge power of the battery assembly, the control unit is used to control the discharge power of the battery assembly to be greater than the maximum nominal discharge power during the time period from when the power supply is powered off to when the first load is powered off after the power supply is powered off, and the maximum nominal discharge power is the maximum power allowed when the battery assembly is normally discharged; After the first load is powered off, controlling the battery assembly to restore the maximum nominal discharge power; or, When the discharge capacity of the battery assembly is characterized by the discharge current of the battery assembly, the control unit is used to control the discharge current of the battery assembly to be greater than the maximum nominal discharge current during the time period from the power failure of the power supply to the power failure of the first load after the power failure of the power supply. The maximum nominal discharge current is the maximum current allowed during normal discharge of the battery assembly; and control the battery assembly to restore the maximum nominal discharge current after the first load is powered off.

3. The battery assembly according to claim 1 or 2, characterized in that: The first load is used to implement 5G data services, and the second load is used for voice services and transmission services other than 5G data services.

4. The battery assembly according to any one of claims 1 to 3, characterized in that: The control unit is further configured to control the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly when the port voltage of the battery assembly in a charging state or a standby state is less than or equal to a second preset voltage.

5. The battery assembly according to any one of claims 1 to 4, characterized in that: The battery assembly also includes: a battery cell pack; The first end of the DC-DC converter is electrically connected to the positive electrode of the battery pack, the second end of the DC-DC converter is electrically connected to the negative electrode of the battery pack, the third end of the DC-DC converter is electrically connected to the first bus, the fourth end of the DC-DC converter is electrically connected to the second bus, the fifth end of the DC-DC converter is electrically connected to the control unit, the first bus and the second bus are used to provide direct current through the power supply, and the first load and the second load are electrically connected in parallel between the first bus and the second bus; The control unit is specifically configured to control the DC-DC converter to reduce the equivalent loop impedance of the battery assembly based on the first pulse width of the first signal, so as to control the discharge capacity of the battery assembly to be greater than the maximum nominal discharge capacity of the battery assembly; after a preset time, based on the second pulse width of the first signal, control the DC-DC converter to increase the equivalent loop impedance of the battery assembly, so as to control the discharge capacity of the battery assembly to be restored to the maximum nominal discharge capacity of the battery assembly; The first pulse width is greater than or equal to the second pulse width, and the pulse width of the first signal is used to adjust the equivalent loop impedance of the battery assembly to control the discharge power or discharge current of the battery assembly.

6. An energy storage system, characterized in that: include: A power supply assembly, a first busbar, a second busbar and a battery assembly as described in any one of claims 1 to 5.

7. The energy storage system according to claim 6, characterized in that: The energy storage system further includes: a monitoring unit, the monitoring unit being electrically connected to the power supply assembly; The power supply component is used to send a power failure alarm signal to the monitoring unit after the power supply source fails; The monitoring unit is further configured to control the secondary loads in the power loads to power off when receiving the power-off alarm signal.

8. The energy storage system according to claim 6 or 7, characterized in that: The energy storage system includes any one of the following: a data center, a communication site or an energy storage power station.

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