CN114300764A - Battery modules and energy storage systems - Google Patents

Abstract

An embodiment of the present application provides a battery module and an energy storage system, including: at least two battery packs and at least two switch units; the switch units are configured to be connected to the battery packs in a one-to-one correspondence; the switch unit includes a first switch , a second switch and a third switch; the first end of the first switch is coupled to the positive pole of the battery pack, the second end of the first switch and the busbar are coupled to the first connection point, and the first end of the second switch is coupled to the battery pack The negative pole of the second switch, the second end of the second switch and the busbar are coupled to the second connection point, the third end of the second switch is coupled to the busbar, and the third switch is arranged between the first connection point and the second connection point. By controlling the turn-on or turn-off of the first switch, the second switch and the third switch in each switch unit, the series connection mode or parallel connection mode can be freely switched between multiple battery packs, thereby improving the performance of the energy storage system. compatibility.

Description

Battery modules and energy storage systems

technical field

The embodiments of the present application relate to the technical field of batteries, and in particular, to a battery module and an energy storage system.

Background technique

With the development of intelligent control technology, developed industrial countries have taken smart grid construction as an important strategic measure to seize the commanding heights of the future low-carbon economy. As a key link of smart grid, energy storage technology has the functions of peak shaving and valley filling and smooth access to new energy, which makes it have broad application prospects in the power system.

The energy storage system is the core equipment in the energy storage technology. The connection mode switching between the battery packs in the current energy storage system is inflexible, the application scenario is single, and the compatibility is poor.

SUMMARY OF THE INVENTION

The embodiments of the present application provide a battery module and an energy storage system, so as to flexibly switch the connection mode between the battery packs and improve the compatibility of the energy storage system.

In a first aspect, an embodiment of the present application provides a battery module, including: at least two battery packs and at least two switch units. Each switch unit is configured to be connected with each battery pack in one-to-one correspondence. Each switch unit includes a first switch, a second switch and a third switch. The first end of the first switch is coupled to the positive electrode of the battery pack, the second end of the first switch and the busbar are coupled to the first connection point, the first end of the second switch is coupled to the negative electrode of the battery pack, and the second end of the second switch is coupled to the negative electrode of the battery pack. The second end and the bus bar are coupled to the second connection point, the third end of the second switch is coupled to the bus bar, and the third switch is disposed between the first connection point and the second connection point. By setting a plurality of switch units to be connected to a plurality of battery packs, the switches in the switch units can be controlled to change the connection between each battery pack and the bus bar, and flexibly switch the series/parallel connection mode of each battery pack.

In some embodiments, the second switch includes a first sub-switch and a second sub-switch. The first sub-switch and the second sub-switch are coupled in parallel between the negative electrode of the battery pack and the bus bar.

In some embodiments, the circuit further includes a control unit, wherein the control unit is configured to control the on-off of the switch unit to form a series connection or a parallel connection between each battery pack.

In some embodiments, when the first switch in each switch unit is turned on, the third switch in each switch unit is turned off, and the first end and the second end of the second switch in each switch unit are turned on, each A series connection is formed between the battery packs. By controlling the switch states of each switch in the switch unit, the battery packs can be connected in series.

In some embodiments, when the first switch in each switch unit is turned on, the third switch in each switch unit is turned on, and the first end and the third end of the second switch in each switch unit are turned on, each battery A parallel connection is formed between the packages. By controlling the switch states of each switch in the switch unit, the battery packs can be connected in parallel.

In some embodiments, when any battery pack satisfies at least one of condition (a1), condition (b1), condition (c1), condition (d1), and condition (e1), the corresponding battery pack is disconnected from the bus bar. Wherein, the condition (a1) is: the absolute value of the voltage difference between the battery pack voltage and the battery pack average voltage exceeds the first threshold range, or the absolute value of the voltage difference between the battery pack voltage and the maximum value of the battery pack voltage exceeds the second Threshold range. Condition (b1) is: the absolute value of the SOC difference between the battery pack SOC and the battery pack average SOC exceeds the third threshold range, or the absolute value of the SOC difference between the battery pack SOC and the battery pack SOC maximum value exceeds the fourth threshold range . The condition (c1) is: the battery pack fails. Condition (d1) is: the absolute value of the temperature difference between the battery pack temperature and the battery pack average temperature exceeds the fifth threshold range, or the battery pack temperature exceeds the first temperature threshold. Condition (e1) is: the absolute value of the SOH difference between the battery pack SOH and the battery pack average SOH exceeds the sixth threshold range, or the absolute value of the SOH difference between the battery pack SOH and the battery pack SOH maximum value exceeds the seventh threshold range .

By disconnecting a battery pack from the bus bar when an abnormality occurs, the safety and reliability of the battery module during operation are improved, and at the same time, the maintenance difficulty of the battery pack is reduced.

In some embodiments, disconnecting the corresponding battery pack from the bus bar comprises: disconnecting the first switch, disconnecting the connection between the first end and the second end of the second switch, so that the battery packs in series connection Disconnecting from the bus bar; alternatively, disconnecting the first switch and disconnecting the connection between the first and third ends of the second switch to disconnect the battery packs in parallel connection from the bus bar. In this way, when a certain battery pack does not meet the specified requirements, it can be disconnected from the bus bar, and other battery packs can be ensured to be in a normal connection mode, thereby ensuring that the system can still continue to work.

In some embodiments, after the battery pack is disconnected from the bus bar, when at least one of condition (a2), condition (b2), condition (c2), condition (d2), condition (e2) is satisfied, restore The connection between the battery pack and the busbar. Wherein, the condition (a2) is: the absolute value of the voltage difference between the battery pack voltage and the battery pack average voltage does not exceed the first threshold range, or the absolute value of the voltage difference between the battery pack voltage and the maximum value of the battery pack voltage does not exceed The second threshold range. Condition (b2) is: the absolute value of the SOC difference between the battery pack SOC and the battery pack average SOC does not exceed the third threshold range, or the absolute value of the SOC difference between the battery pack and the battery pack SOC maximum value does not exceed the fourth threshold value scope. The condition (c2) is that the battery pack is a normal battery pack that replaces the faulty battery pack. Condition (d2) is: the absolute value of the temperature difference between the battery pack temperature and the battery pack average temperature does not exceed the fifth threshold range, or the battery pack temperature does not exceed the first temperature threshold. Condition (e2) is: the absolute value of the SOH difference between the battery pack SOH and the battery pack average SOH does not exceed the sixth threshold range, or the absolute value of the SOH difference between the battery pack SOH and the battery pack SOH maximum value does not exceed the seventh Threshold range.

When a battery pack is disconnected from the busbar and its parameters return to the specified range, it can be reconnected to the busbar, which can improve the safety and reliability of the battery module during operation, and improve the convenience of maintenance. sex.

In some embodiments, restoring the connection between the battery pack and the bus includes: turning on the first switch, turning on the connection between the first end and the second end of the second switch, and turning off the third switch, so that the The battery packs connected in series are restored to the connection with the bus bar; or, the first switch is turned on, the connection between the first terminal and the third terminal of the second switch is turned on, and the third switch is turned on, so as to be in a parallel connection The battery pack restores connection to the bus. In this way, when a battery pack disconnected from the busbar meets the specified requirements, it can be restored to the busbar and connected to other battery packs in a specified manner, thereby ensuring that the system can still continue to work.

In a second aspect, an embodiment of the present application further provides an energy storage system, including an inverter unit, and the battery module according to any one of the first aspect. The inverter unit is electrically connected to each battery pack through a bus bar. Wherein, when the battery module includes a control unit, the control unit controls the switch unit to switch on and off in response to a first indication signal of the inverter unit, and the first indication signal includes the type of the inverter unit. In this way, the convenience and adaptability of the energy storage system are improved.

In some embodiments, when the battery module includes the control unit, the inverter unit limits the bus current to the first current threshold in response to the second indication signal from the control unit, so as to ensure the operational reliability and reliability of the energy storage system. safety.

In some embodiments, the energy storage system further includes a DCDC unit. The inverter unit is connected to the bus through the DCDC unit to improve the adaptability of the energy storage system.

Compared with the prior art, the beneficial effects of one or more embodiments of the present application include: different from the prior art, the embodiments of the present application provide a battery module and an energy storage system, including: at least two a battery pack and at least two switch units; the switch units are configured to be connected with the battery packs in one-to-one correspondence; the switch unit includes a first switch, a second switch and a third switch; the first end of the first switch is coupled to the battery pack The positive pole, the second end of the first switch and the busbar are coupled to the first connection point, the first end of the second switch is coupled to the negative pole of the battery pack, the second end of the second switch and the busbar are coupled to the second connection point, the second The third end of the switch is coupled to the bus bar, and the third switch is disposed between the first connection point and the second connection point. By controlling the on or off of the first switch, the second switch and the third switch in each switch unit, the series connection mode or parallel connection mode can be freely switched between multiple battery packs, thereby improving the performance of the energy storage system. compatibility.

Description of drawings

One or more embodiments are exemplified by the pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations to the embodiments, and the elements/modules and steps with the same reference numerals in the drawings represent For similar elements/modules and steps, the figures in the accompanying drawings do not constitute a scale limitation unless otherwise stated.

1 is a schematic structural diagram of a battery module provided by an embodiment of the present application;

Fig. 2 is a kind of connection schematic diagram of Fig. 1;

Fig. 3 is another connection schematic diagram of Fig. 1;

4 is a schematic structural diagram of another battery module provided by an embodiment of the present application;

Fig. 5 is a kind of connection schematic diagram of Fig. 4;

Fig. 6 is another kind of connection schematic diagram of Fig. 4;

Fig. 7 is another kind of connection schematic diagram of Fig. 1;

Fig. 8 is another connection schematic diagram of Fig. 1;

FIG. 9 is a schematic structural diagram of an energy storage system provided by an embodiment of the present application.

Detailed ways

The present application will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application. These all belong to the protection scope of the present application.

In order to facilitate the understanding of the present application, the present application will be described in more detail below with reference to the accompanying drawings and specific embodiments. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the technical field belonging to this application. The terms used in the specification of the present application are only for the purpose of describing specific embodiments, and are not used to limit the present application. As used in this specification, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that, if there is no conflict, various features in the embodiments of the present application may be combined with each other, which are all within the protection scope of the present application. In addition, although the functional modules are divided in the schematic diagram of the device, in some cases, the modules may be divided differently from the device. In addition, the words "first" and "second" used herein do not limit the data and execution order, but only distinguish the same or similar items with substantially the same function and effect.

In recent years, the state has vigorously advocated energy conservation and environmental protection. The energy storage system can shave peaks and fill valleys in the power grid, and provide power resource supplementation and regulation for the construction of intelligent cities and intelligent buildings. Among them, the energy storage system can be connected to the load/grid, so that when the energy storage system is connected to the grid, the electrical energy in the grid can charge the energy storage system, and when the energy storage system is connected to the load, the energy stored in the energy storage system The electrical energy can discharge the load, allowing the energy storage system to act as a backup power source.

The energy storage system includes a battery module and an inverter unit, wherein the battery module includes a plurality of battery packs, and in an implementation manner of the battery module, the plurality of battery packs are connected in a fixed connection manner. For example, the plurality of battery packs are connected in a fixed series connection, or are connected in a fixed parallel connection. When the connection method between the battery packs needs to be switched, the connection method between the battery packs needs to be switched by manually changing the wiring method.

In addition, in the battery module under this fixed connection method, if there is a battery pack failure and cannot work, the entire system will be immediately paralyzed. To restore the system to work normally, the faulty battery pack needs to be replaced immediately. The maintenance difficulty of the whole system increases. In addition, if the voltage difference needs to be equalized between the battery packs, the voltage difference cannot be automatically equalized between the battery packs, and additional auxiliary equipment is often required for equalization.

The embodiment of the present application also provides an implementation manner of a battery module. In the battery module, a plurality of switch units are arranged to be connected to a plurality of battery packs correspondingly, and the switch units are correspondingly arranged between the battery packs and the bus bar. , for each battery pack, the connection between each battery pack and the bus bar can be changed by turning on or off each switch in the switch unit. Therefore, the connection mode between the battery packs can be freely switched, and when a battery pack fails, the system can make adjustments immediately, so that the system can continue to maintain normal operation, and the problem of difficulty in balancing between the battery packs can be solved.

Please refer to FIG. 1 , the battery module 100 includes: at least two battery packs and at least two switch units. Wherein, each switch unit is configured to be connected with each battery pack in one-to-one correspondence. Each switch unit includes a first switch, a second switch and a third switch. The first end of the first switch is coupled to the positive electrode of the battery pack, the second end of the first switch and the busbar are coupled to the first connection point, the first end of the second switch is coupled to the negative electrode of the battery pack, and the second end of the second switch is coupled to the negative electrode of the battery pack. The second end and the bus bar are coupled to the second connection point, the third end of the second switch is coupled to the bus bar, and the third switch is disposed between the first connection point and the second connection point.

FIG. 1 shows the first battery pack 11 , the second battery pack 12 , the first switch unit 21 and the second switch unit 22 . The first battery pack 11 is connected to the first switch unit 21 correspondingly. The first switch unit 21 includes a first switch S11, a second switch S21 and a third switch S31. The second battery pack 12 is connected to the second switch unit 22 correspondingly. The second switch unit 22 includes a first switch S12 , a second switch S22 and a third switch S32 , and the specific connection method thereof can be referred to the above description, which will not be repeated here.

Wherein, the battery pack may include only one battery cell, or may include at least two battery cells connected in series and/or parallel. A switch refers to an electronic component with at least two states of on (on) and off (off), so that the components connected at both ends of the switch can be switched between the two states of connection and disconnection. Specifically, the switch may include at least one of triodes, field effect transistors, insulated gate bipolar transistors, relays, etc., which have at least two different states of "on" and "off", and are electrical appliances that can play a switching role element.

Specifically, in the battery module 100, a plurality of switch units are arranged to be connected to a plurality of battery packs correspondingly, and the switch units are correspondingly arranged between the battery packs and the bus bar, so that for each battery pack, the The first switch, the second switch and the third switch in the switch unit are turned on or off to change the connection between each battery pack and the bus bar.

In this way, each battery pack can be connected in series, or can be connected in parallel between each battery pack, so that the serial/parallel connection mode of each battery pack can be flexibly switched, so as to meet different requirements. to improve the compatibility and adaptability of battery modules. In addition, it is also possible to disconnect a certain battery pack from the busbar by controlling the switch state of a certain switch unit, and ensure the normal connection between other battery packs, or restore the disconnected battery pack to the busbar. In this way, by controlling the switch state in the switch unit, the connection between one or more battery packs and the busbar can be flexibly disconnected, or the connection between them and the busbar can be restored, which can be used to achieve balance between batteries or It is to eliminate faults, and to improve the convenience and flexibility for the replacement of battery packs, reduce the difficulty of after-sales maintenance, and improve the user experience.

In some embodiments, please continue to refer to FIG. 1 , the battery module 100 further includes a positive terminal P+ and a negative terminal P-. In each switch unit, the first end of the first switch is connected to the positive terminal of the battery pack, and the first switch The second end of the second switch and the positive bus bar are connected to the first connection point, the first end of the second switch is connected to the negative electrode of the battery pack, the second end of the second switch and the positive bus bar are connected to the second connection point, and the third end of the second switch is connected to the second connection point. The terminal is connected to the negative bus bar, the first terminal of the third switch is connected to the first connection point, and the second terminal of the third switch is connected to the second connection point.

In the battery module, each battery pack is connected to the bus bar through a corresponding switch unit, so that the subsequent switch state of each switch unit can be controlled, so that each battery pack is connected in series or in parallel. Thereby, the connection mode between the battery packs can be freely switched, and the compatibility and adaptability are improved. In addition, the connection between a certain battery pack and the busbar can also be individually controlled to be turned on or off, so that a certain battery pack can be cut out or into the entire system without affecting the normal operation of other battery packs, reducing the difficulty of after-sales maintenance. .

In some embodiments, when the first switch in each switch unit is turned on, the third switch in each switch unit is turned off, and the first end and the second end of the second switch in each switch unit are turned on, each A series connection is formed between the battery packs.

For example, referring to FIG. 2, in the battery module, for the first switch unit 21, the connection between the first end and the second end of the first switch S11 is turned on, and the first end and the second end of the third switch S31 are turned on. The connection between the two ends is disconnected, and the connection between the first end and the second end of the second switch S21 is turned on; for the second switch unit 22, the connection between the first end and the second end of the first switch S12 The connection is turned on, the connection between the first end and the second end of the third switch S32 is disconnected, and the connection between the first end and the second end of the second switch S22 is turned on. In this way, for each battery pack, the positive pole of the battery pack and the bus bar are connected at the first connection point, the negative pole of the battery pack and the bus bar are connected to the second connection point, and a series connection is formed between the battery packs. It can be seen that by controlling the switch states of each switch in the switch unit, the battery packs can be connected in series.

In some embodiments, when the first switch in each switch unit is turned on, the third switch in each switch unit is turned on, and the first end and the third end of the second switch in each switch unit are turned on, each battery A parallel connection is formed between the packages.

For example, referring to FIG. 3, in the battery module, for the first switch unit 21, the connection between the first end and the second end of the first switch S11 is turned on, and the first end and the second end of the third switch S31 are turned on. The connection between the two ends is turned on, and the connection between the first end and the third end of the second switch S21 is turned on; for the second switch unit 22, the connection between the first end and the second end of the first switch S12 The connection is turned on, the connection between the first end and the second end of the third switch S32 is turned on, and the connection between the first end and the third end of the second switch S22 is turned on. In this way, for each battery pack, the positive pole of the battery pack is connected to the positive terminal P+, the negative pole of the battery pack is connected to the negative terminal P-, and the battery packs are connected in parallel. It can be seen that by controlling the switch states of each switch in the switch unit, the battery packs can be connected in a parallel connection manner.

To sum up, the battery modules provided in the embodiments of the present application can flexibly switch the series connection or parallel connection of the battery packs by controlling the on or off of each switch in the switch unit, thereby improving the compatibility of the battery modules , to meet different application scenarios and improve the adaptability of battery modules.

In some embodiments, the second switch includes a first sub-switch and a second sub-switch. Wherein, the first sub-switch and the second sub-switch are coupled in parallel between the negative electrode of the battery pack and the bus bar.

For example, referring to FIG. 4 , the second switch in the first switch unit 21 includes a first sub-switch S211 and a second sub-switch S212, and the first terminal of the first sub-switch S211 and the first terminal of the second sub-switch S212 are both The negative terminal of the first battery pack 11 is connected, the second terminal of the first sub-switch S211 and the bus bar are connected to the second connection point, and the second terminal of the second sub-switch S212 is connected to the negative terminal P-.

In the battery module, please refer to FIG. 5 , when the connection between the first end and the second end of the first switch of each switch unit is turned on, and the connection between the first end and the second end of the third switch is turned on When disconnected, the connection between the first end and the second end of the first sub-switch is turned on, and the connection between the first end and the second end of the second sub-switch is disconnected, the negative electrode of the battery pack and the positive electrode terminal P+ connected to form a series connection between the battery packs. Referring to FIG. 6, when the connection between the first end and the second end of the first switch is turned on, the connection between the first end and the second end of the third switch is turned on, and the first end of the first sub-switch is turned on. When the connection between The negative electrodes are all connected to the negative terminal P-, and the battery packs are connected in parallel. It can be seen that by controlling the on or off of the first switch, the second switch, the first sub-switch and the second sub-switch, the series/parallel connection between the battery packs can be switched.

In some embodiments, the circuit further includes: a control unit. Wherein, the control unit is configured to control the on-off of the switch unit, so as to form a series connection or a parallel connection between the battery packs.

The switches in this embodiment all have at least one control terminal, the control terminal of each switch is connected to the control unit, and each switch can be correspondingly between two states of on and off according to different control signals of the control unit. switch. The control unit can be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller, an ARM (Acorn RISC Machine) or other programmable logic devices, discrete gates or Transistor logic, discrete hardware components, or any combination of these. The control unit can be used to output control signals to the control terminals of each switch, so as to control the on or off state of each switch in the switch unit, so as to realize the connection between the battery pack and the bus bar.

Specifically, the battery module may include only one control unit, the control unit is respectively connected to the control terminal of each switch of each switch unit, and outputs control signals to each switch through different output ports. When the number of switches is large, in order to facilitate management, the battery module can also be provided with multiple control units, wherein the number of control units is equal to the number of battery packs, and each control unit corresponds to each switch unit. , and can also control the switching state of each switch. In practical applications, the number of control units can be set according to actual needs, which is not limited here.

In some embodiments, when the battery pack satisfies the condition (a1), the battery pack is disconnected from the bus bar. Wherein, the condition (a1) is: the absolute value of the voltage difference between the battery pack voltage and the battery pack average voltage exceeds the first threshold range, or the absolute value of the voltage difference between the battery pack voltage and the maximum value of the battery pack voltage exceeds the second Threshold range.

Specifically, first obtain the voltage value of each battery pack that is connected to the busbar; then, calculate the average voltage of the battery pack that is connected to the busbar; then, calculate the voltage of each battery pack that is connected to the busbar. Make the difference with the average voltage and take the absolute value to obtain the absolute value of the voltage difference corresponding to each battery pack connected to the busbar; judge whether the absolute value of the voltage difference exceeds the first threshold range one by one. When the absolute value of the voltage difference exceeds the first threshold range, the battery pack is disconnected from the bus bar.

Or, when each battery pack is in a discharge state, first obtain the voltage value of each battery pack connected to the busbar; then, obtain the maximum voltage value of the battery pack connected to the busbar; then, connect each battery pack to the busbar Take the difference between the voltage value of the battery pack that is turned on and the maximum voltage value of the battery pack and take the absolute value to obtain the absolute value of the voltage difference corresponding to each battery pack that is connected to the busbar; judge whether the absolute value of the voltage difference exceeds the second one. Threshold range, if the absolute value of the voltage difference corresponding to a battery pack exceeds the second threshold range, disconnect the battery pack from the busbar.

Alternatively, when each battery pack is in a charged state, first obtain the voltage value of each battery pack that is connected to the busbar; then, obtain the minimum voltage value of the battery pack that is connected to the busbar; then, connect each battery pack to the busbar Take the difference between the voltage value of the battery pack that is turned on and the minimum voltage value of the battery pack and take the absolute value to obtain the absolute value of the voltage difference corresponding to each battery pack that is connected to the busbar; judge one by one whether the absolute value of the voltage difference exceeds the second Threshold range, if the absolute value of the voltage difference corresponding to a battery pack exceeds the second threshold range, disconnect the battery pack from the busbar.

By judging the absolute value of the voltage difference between the battery pack voltage and the average voltage of the battery pack, or judging the absolute value of the voltage difference between the battery pack voltage and the maximum value of the battery pack voltage, the absolute value of the voltage difference exceeds the first threshold range or the second The battery packs within the threshold range are disconnected from the busbar to ensure that the voltage between the battery packs connected to the busbar meets the specified requirements, so that the battery module can work under normal conditions.

In some embodiments, when the battery pack satisfies the condition (a2), the connection of the battery pack to the bus bar is restored. Wherein, the condition (a2) is: the absolute value of the voltage difference between the battery pack voltage and the battery pack average voltage does not exceed the first threshold range, or the absolute value of the voltage difference between the battery pack voltage and the maximum value of the battery pack voltage does not exceed The second threshold range.

Specifically, when a battery pack is disconnected from the bus bar, the voltage value of each battery pack can be obtained first; then, the average voltage of the battery pack can be calculated; then, the voltage value of the battery pack disconnected from the bus bar can be obtained. Make a difference with the average voltage and take the absolute value to obtain the absolute value of the voltage difference corresponding to the battery pack disconnected from the busbar; judge whether the absolute value of the voltage difference does not exceed the first threshold range, if the absolute value of the voltage difference corresponding to the battery pack If the range of the first threshold value is not exceeded, the connection between the battery pack and the bus bar is re-conducted.

Or, when each battery pack is in the discharge state, when the connection between the battery pack and the busbar is disconnected, first obtain the voltage value of each battery pack; then, obtain the maximum voltage value of the battery pack; then, disconnect the connection from the busbar Take the difference between the voltage value of the battery pack and the maximum voltage value of the battery pack and take the absolute value to obtain the absolute value of the voltage difference corresponding to the battery pack disconnected from the busbar; judge one by one whether the absolute value of the voltage difference does not exceed the second threshold range, If the absolute value of the voltage difference corresponding to a certain battery pack does not exceed the second threshold range, the connection between the battery pack and the bus bar is re-conducted.

Or, when each battery pack is in the charging state, when the connection between the battery pack and the busbar is disconnected, first obtain the voltage value of each battery pack; then, obtain the minimum voltage value of the battery pack; then, disconnect the connection from the busbar Take the difference between the voltage value of the battery pack and the minimum voltage value of the battery pack and take the absolute value to obtain the absolute value of the voltage difference corresponding to the battery pack disconnected from the busbar; judge whether the absolute value of the voltage difference does not exceed the second threshold range, If the absolute value of the voltage difference corresponding to the battery pack does not exceed the second threshold range, the connection between the battery pack and the bus bar is re-conducted.

When the connection between the battery pack and the bus is disconnected, by judging the absolute value of the voltage difference between the battery pack voltage and the average voltage of the battery pack, or judging the absolute value of the voltage difference between the battery pack voltage and the maximum value of the battery pack voltage, the The battery pack whose absolute value of the voltage difference does not exceed the first threshold range or the second threshold range is restored to be connected to the bus bar. In this way, when the absolute value of the voltage difference of the battery pack does not meet the regulations, it can be disconnected from the bus bar, and when the absolute value of the voltage difference of the battery pack meets the regulations, the connection with the bus bar can be turned on. In this way, the balance-free function between the battery packs can be realized.

In some embodiments, when the battery pack satisfies the condition (b1), the battery pack is disconnected from the bus bar. Wherein, the condition (b1) is: the absolute value of the SOC difference between the battery pack SOC and the battery pack average SOC exceeds the third threshold range, or the absolute value of the SOC difference between the battery pack SOC and the battery pack SOC maximum value exceeds the fourth threshold Threshold range.

Among them, SOC refers to the state of charge of the battery pack, which can be used to reflect the remaining capacity of the battery pack. Specifically, first obtain the SOC of each battery pack that is connected to the busbar; then, calculate the average SOC of the battery pack that is connected to the busbar, and then calculate the SOC value of each battery pack that is connected to the busbar Make a difference with the average SOC and take the absolute value to obtain the absolute value of the SOC difference corresponding to each battery pack connected to the bus; judge whether the absolute value of the SOC difference exceeds the third threshold range one by one. If the SOC corresponding to a certain battery pack If the absolute value of the difference exceeds the third threshold range, the battery pack is disconnected from the bus bar.

Or, when each battery pack is in a discharging state, first obtain the SOC value of each battery pack that is connected to the busbar; then, obtain the maximum SOC value of the battery pack that is connected to the busbar; then, connect each battery pack to the busbar Make the difference between the SOC value of the connected battery pack and the maximum SOC value of the battery pack and take the absolute value; judge whether the absolute value of the SOC difference exceeds the fourth threshold range one by one, if the absolute value of the SOC difference corresponding to a battery pack exceeds the fourth threshold value range, disconnect the battery pack from the busbar.

Or, when each battery pack is in a charged state, first obtain the SOC value of each battery pack that is connected to the busbar; then, obtain the minimum SOC value of the battery pack that is connected to the busbar; then, connect each battery pack to the busbar Take the difference between the SOC value of the battery pack that is turned on and the minimum SOC value of the battery pack and take the absolute value to obtain the absolute value of the SOC difference corresponding to each battery pack that is connected to the bus; judge one by one whether the absolute value of the SOC difference exceeds the fourth Threshold value range, if the absolute value of the SOC difference corresponding to a certain battery pack exceeds the fourth threshold value range, the connection between the battery pack and the busbar is disconnected, and the connection between the battery pack and the busbar is disconnected.

By judging the absolute value of the SOC difference between the battery pack SOC and the battery pack average SOC, or judging the SOC difference absolute value between the battery pack SOC and the battery pack SOC maximum value, the absolute value of the SOC difference exceeds the third threshold range or the fourth The connection between the battery packs in the threshold range and the bus bar is disconnected to ensure that the SOC between the battery packs under the working system meets the specified requirements, so that the battery module works under normal conditions.

In some embodiments, when the battery pack satisfies the condition (b2), the connection of the battery pack to the bus bar is restored. Wherein, condition (b2) is: the absolute value of the SOC difference between the battery pack SOC and the battery pack average SOC does not exceed the third threshold range, or the absolute value of the SOC difference between the battery pack and the battery pack SOC maximum value does not exceed the third threshold range Four threshold ranges.

Specifically, when a battery pack is disconnected from the bus, first obtain the SOC of each battery pack; then, calculate the average SOC of the battery pack, and then compare the SOC value of the battery pack disconnected from the bus with the average Perform SOC difference and take the absolute value to obtain the absolute value of the SOC difference corresponding to the battery pack disconnected from the bus; judge whether the absolute value of the SOC difference does not exceed the third threshold range, if the absolute value of the SOC difference corresponding to the battery pack does not exceed In the third threshold range, the connection between the battery pack and the bus bar is re-conducted.

Or, when each battery pack is in a discharging state, first obtain the SOC value of each battery pack; then, obtain the maximum SOC value of the battery pack; then, compare the SOC value of the battery pack disconnected from the bus bar with the maximum SOC value of the battery pack Make a difference and take the absolute value to obtain the absolute value of the SOC difference corresponding to the battery pack disconnected from the bus; judge whether the absolute value of the SOC difference does not exceed the fourth threshold range, if the absolute value of the SOC difference corresponding to the battery pack does not exceed In the fourth threshold range, the connection between the battery pack and the busbar is re-conducted.

Or, when each battery pack is in the charging state, first obtain the SOC value of each battery pack; then, obtain the minimum SOC value of the battery pack; then, compare the SOC value of the battery pack disconnected from the bus bar with the minimum SOC value of the battery pack Make the difference and take the absolute value to obtain the absolute value of the SOC difference of the battery pack disconnected from the bus; judge whether the absolute value of the SOC difference does not exceed the fourth threshold range, if the absolute value of the SOC difference corresponding to the battery pack does not exceed the fourth threshold range, then the connection between the battery pack and the busbar is re-conducted.

By judging the absolute value of the SOC difference between the battery pack SOC after disconnection from the busbar and the average battery pack SOC, or by judging the SOC difference between the battery pack SOC after disconnection from the busbar and the maximum value of the battery pack SOC Absolute value, restore the connection to the bus bar of the battery pack whose absolute value of the SOC difference does not exceed the third threshold value range or the fourth threshold value range, and conduct the connection with the bus bar again. In this way, when the absolute value of the SOC difference between the battery packs does not meet the regulations, the connection with the busbar can be disconnected, and when the absolute value of the SOC difference between the battery packs meets the regulations, the connection with the busbar can be turned on. , so that the balance-free function between battery packs can be realized.

In some embodiments, when the battery pack satisfies the condition (c1), the battery pack is disconnected from the bus bar. Wherein, the condition (c1) is: the battery pack fails.

Specifically, when one or more battery packs that are connected to the busbar are in an abnormal situation such as liquid leakage or abnormal voltage, the connection between these battery packs and the busbar is disconnected. Disconnecting the faulty battery pack from the bus bar in this way not only facilitates maintenance of the faulty battery pack by maintenance technicians, but also ensures the normal operation of the battery module.

In some embodiments, when the battery pack satisfies the condition (c2), the connection of the battery pack to the bus bar is restored. Wherein, the condition (c2) is: the battery pack is a normal battery pack that replaces the faulty battery pack.

Specifically, when the connection between the faulty battery pack and the bus is disconnected, a normal battery pack can be used to replace it, and when a normal battery pack is detected to replace the faulty battery pack, the connection between the battery pack and the bus is restored. This improves maintenance convenience.

In some embodiments, when the battery pack satisfies the condition (d1), the battery pack is disconnected from the bus bar. Wherein, condition (d1): the absolute value of the temperature difference between the temperature of the battery pack and the average temperature of the battery pack exceeds the fifth threshold range, or the temperature of the battery pack exceeds the first temperature threshold.

Specifically, first obtain the temperature of each battery pack that is connected to the busbar; then, calculate the average temperature of the battery pack that is connected to the busbar; then, calculate the temperature value of each battery pack that is connected to the busbar. Make a difference with the average temperature and take the absolute value to obtain the absolute value of the temperature difference corresponding to each battery pack connected to the busbar; judge whether the absolute value of the temperature difference exceeds the third threshold range one by one. If the absolute value of the difference exceeds the fifth threshold range, the battery pack is disconnected from the bus bar.

Alternatively, first obtain the temperature of each battery pack connected to the busbar, and then determine whether the temperature of each battery pack connected to the busbar exceeds the first temperature threshold, for example, whether it exceeds 100°C, and if it exceeds the first temperature threshold , disconnect the battery pack from the busbar.

Through the above method, it can be ensured that the temperature of the battery pack is kept under the specified requirements to work, thereby improving the safety and reliability of the battery module.

In some embodiments, when the battery pack satisfies the condition (d2), the connection of the battery pack to the bus bar is restored. Wherein, the condition (d2) is: the absolute value of the temperature difference between the battery pack temperature and the battery pack average temperature does not exceed the fifth threshold range, or the battery pack temperature does not exceed the first temperature threshold.

Specifically, when a battery pack is disconnected from the busbar, first obtain the temperature of each battery pack; then, calculate the average temperature of each battery pack; then, compare the temperature value of the battery pack disconnected from the busbar to the Take the difference of the average temperature and take the absolute value to obtain the absolute value of the temperature difference corresponding to the battery pack disconnected from the bus bar; judge whether the absolute value of the temperature difference does not exceed the fifth threshold range, if the absolute value of the temperature difference does not exceed the fifth threshold threshold range, then the connection between the battery pack and the busbar is re-conducted.

Alternatively, first obtain the temperature of each battery pack disconnected from the bus bar, and then determine whether the temperature of each battery pack disconnected from the bus bar does not exceed the first temperature threshold, for example, whether it exceeds 100°C, and if it does not exceed the first temperature threshold If the temperature threshold is exceeded, the connection between the battery pack and the busbar is re-conducted.

In the above manner, when the temperature of the battery pack returns to a specified range, the bus bar can be reconnected, thereby ensuring the safety and reliability of the battery module.

In some embodiments, when the battery pack satisfies the condition (e1), the battery pack is disconnected from the bus bar. Wherein, the condition (e1) is: the absolute value of the SOH difference between the battery pack SOH and the battery pack average SOH exceeds the sixth threshold range, or the absolute value of the SOH difference between the battery pack SOH and the battery pack SOH maximum value exceeds the seventh Threshold range.

Among them, SOH is a quantitative indicator of the battery health state of the battery pack, which can be used to reflect the battery health state of the battery pack. Specifically, first obtain the SOH of each battery pack that is connected to the busbar; then, calculate the average SOH of the battery pack that is connected to the busbar; then, calculate the SOH value of each battery pack that is connected to the busbar Make the difference with the average SOH and take the absolute value; get the absolute value of the SOH difference corresponding to each battery pack connected to the busbar; judge whether the absolute value of the SOH difference exceeds the sixth threshold range one by one, if the SOH corresponding to a battery pack If the absolute value of the difference exceeds the sixth threshold range, the battery pack is disconnected from the bus bar.

Alternatively, first obtain the SOH value of each battery pack that is connected to the busbar; then, obtain the maximum SOH value of the battery pack that is connected to the busbar; then, compare the SOH value of each battery pack that is connected to the busbar with Calculate the maximum SOH value of the battery pack and take the absolute value to obtain the absolute value of the SOH difference corresponding to each battery pack connected to the busbar; judge whether the absolute value of the SOH difference exceeds the seventh threshold range one by one. If the absolute value of the SOH difference exceeds the seventh threshold range, the battery pack is disconnected from the bus bar.

Through the above method, the battery pack with poor battery health status of the battery module can be disconnected from the bus bar, thus improving the working efficiency of the battery module and ensuring the safety of the battery module during operation.

In some embodiments, when the battery pack satisfies the condition (e2), the connection of the battery pack to the bus bar is restored. Wherein, the condition (e2) is: the absolute value of the SOH difference between the battery pack SOH and the battery pack average SOH does not exceed the sixth threshold range, or the absolute value of the SOH difference between the battery pack SOH and the battery pack SOH maximum value does not exceed Seventh threshold range.

Specifically, when a battery pack is disconnected from the busbar, first obtain the SOH of each battery pack; then, calculate the average SOH of the battery pack; then, compare the SOH value of the battery pack disconnected from the busbar with the average Perform SOH difference and take the absolute value to obtain the absolute value of SOH difference corresponding to the battery pack disconnected from the busbar; judge whether the absolute value of the SOH difference does not exceed the sixth threshold range, if the absolute value of the SOH difference does not exceed the sixth threshold threshold range, the connection between the corresponding battery pack and the busbar will be re-conducted.

Or, when a battery pack is disconnected from the busbar, first obtain the SOH value of each battery pack; then, obtain the maximum SOH value of the battery pack; then, compare the SOH value of the battery pack disconnected from the busbar with the battery pack Make the difference of the maximum SOH value and take the absolute value to obtain the absolute value of the SOH difference corresponding to the battery pack disconnected from the busbar; judge whether the absolute value of the SOH difference does not exceed the seventh threshold range, if the absolute value of the SOH difference does not exceed the seventh threshold. Seven threshold ranges, the connection between the corresponding battery pack and the busbar will be re-conducted.

Through the above method, the battery pack whose battery health status meets the regulations can be reconnected to the bus bar, so that the working efficiency of the battery module can be guaranteed.

In some embodiments, when the battery pack satisfies at least one of the above conditions (a1), condition (b1), condition (c1), condition (d1) and condition (e1), the connection between the corresponding battery pack and the bus bar is disconnected connect. Then, when a certain battery pack is abnormal, it can be disconnected from the busbar. When the battery module is charged and discharged, the above method can ensure that the performance parameters of each battery pack meet certain requirements during charging and discharging of the battery module, improve the safety and reliability of the battery module during operation, and at the same time reduce the need for The maintenance difficulty of the battery pack improves the convenience of maintenance.

In some embodiments, after the battery pack is disconnected from the bus bar, when the battery pack disconnected from the bus bar satisfies the above-mentioned condition (a2), condition (b2), condition (c2), condition (d2) and condition When at least one of (e2) is used, the connection between the corresponding battery pack and the busbar is restored. Then, when a battery pack is disconnected from the busbar, and its parameters are restored to the specified required range, it can be reconnected to the busbar. When the battery module is charged, the above method can ensure that the performance parameters of each battery pack of the battery module meet certain requirements during charging and discharging, improve the safety and reliability of the battery module during operation, and reduce the impact on the battery. The maintenance difficulty of the package improves the convenience of maintenance.

It should be noted that the conditions selected for restoring the connection of the battery pack to the busbar generally correspond to the conditions used to disconnect the battery pack from the busbar. Moreover, when determining whether to restore the connection between the battery pack and the bus bar, the battery pack generally needs to meet all the selection conditions before restoring the connection to the bus bar.

It should be noted that the first threshold range, the second threshold range, the third threshold range, the fourth threshold range, the fifth threshold range, the first temperature threshold, the sixth threshold range, and the seventh threshold range can all be determined based on empirical values. Settings, which are not limited here.

In some embodiments, the battery module further includes at least one battery management system, the battery management system is correspondingly connected to the battery pack and the control unit, and the battery management system includes a sampling module, a controller, and the like. The sampling module includes at least one of a voltage sampling module, a current sampling module, and a temperature sampling module. The voltage sampling module is used for real-time acquisition of the voltage of each battery pack, passive balance power, etc.; the current sampling module is used for sampling the current of each battery pack, and the temperature sampling module is used for sampling the temperature of each battery pack. The voltage sampling module, current sampling module and temperature sampling module transmit the collected data to the controller, and the controller determines the voltage, SOH, SOC and temperature of each battery pack according to the collected data, and then calculates the voltage, SOH , SOC and temperature are sent to the control unit. It can be understood that the voltage sampling module, the current sampling module and the temperature sampling module can be implemented by existing chip modules (such as integrated circuits IC) or conventional circuits in the art, and the voltage sampling module, current sampling module and temperature sampling module are not described in detail here. The circuit structure of the temperature sampling module.

In some embodiments, disconnecting the corresponding battery pack from the bus bar includes: disconnecting the first switch, disconnecting the connection between the first end and the second end of the second switch, and turning on the third switch, to Disconnecting the battery packs in series connection from the bus bar; alternatively, disconnecting the first switch and disconnecting the connection between the first and third terminals of the second switch to disconnect the battery packs in parallel connection Open the connection to the busbar.

Specifically, when the battery packs in the battery module are connected in series, as shown in FIG. 2 , if a certain battery pack in the battery module satisfies the condition (a1), condition (b1), condition ( c1), condition (d1), condition (e1), then by controlling the connection between the first end and the second end of the first switch in the switch unit corresponding to the battery pack to be disconnected, the first The connection between the first end and the second end of the second switch is disconnected, and the connection between the first end and the second end of the third switch is turned on, so that the connection between the battery pack and the bus bar is disconnected, and other batteries are ensured. The packages are still in series connection mode.

For example, at this time, if the first battery pack 11 satisfies at least one of the conditions (a1), (b1), (c1), (d1), and (e1), the first switch unit 21 is controlled The connection between the first end and the second end of the first switch S11 is disconnected, the connection between the first end and the second end of the second switch S21 is disconnected, and the first end and the second end of the third switch S31 are disconnected. The connection between the two ends is turned on, as shown in FIG. 7 , so that the connection between the first battery pack 11 and the bus bar is disconnected, and it is ensured that the other battery packs are still connected in series.

When the battery packs in the battery module are connected in parallel, as shown in FIG. 3 , when the battery packs in the battery module satisfy the condition (a1), condition (b1), condition (c1), condition (d1) , at least one of the conditions (e1), then by controlling the connection between the first end and the second end of the first switch in the switch unit of the corresponding battery pack, the connection between the first end and the second end of the first switch is disconnected, and the first end and the second end of the second switch are The connection between the three terminals is disconnected, so that the connection between the battery pack and the busbar is disconnected, but the other battery packs are still connected in parallel, so that when a battery pack is cut out from the parallel-connected working system, the remaining battery packs Still connected in parallel connection, the system can work normally.

For example, at this time, if the first battery pack 11 satisfies at least one of the conditions (a1), (b1), (c1), (d1), and (e1), the first switch unit 21 is controlled The connection between the first end and the second end of the first switch S11 is disconnected, and the connection between the first end and the second end of the second switch S21 is disconnected, as shown in FIG. Pack 11 is disconnected from the bus bar and ensures that the other battery packs are still connected in parallel.

It can be seen that through the above method, when a certain battery pack does not meet the specified requirements, it can be disconnected from the bus bar, and other battery packs are still connected normally, so as to ensure that the system can still continue to work.

In some embodiments, restoring the connection between the battery pack and the bus includes: turning on the first switch, turning on the connection between the first end and the second end of the second switch, and turning off the third switch, so that the Battery packs connected in series restore connection to the bus. Alternatively, the first switch is turned on and the connection between the first end and the third end of the second switch is turned on, so that the battery packs connected in parallel are restored to the bus bar.

Specifically, when the battery packs in the battery module are connected in series, when the battery packs in the battery module satisfy the condition (a2), condition (b2), condition (c2), condition (d2), condition ( When at least one of the conditions in e2) is satisfied, by controlling the connection between the first end and the second end of the first switch in the switch unit corresponding to the battery pack, the connection between the first end and the second end of the first switch is turned on, and the first end and the second end of the second switch are The connection between them is turned on, and the connection between the first end and the second end of the third switch is disconnected, so that the connection between the battery pack and the busbar is turned on, and the battery pack is connected in series with other battery packs.

For example, as shown in FIG. 7 , if the first battery pack 11 satisfies at least one of the conditions (a2), conditions (b2), conditions (c2), conditions (d2), and conditions (e2), the control of the first battery In the switch unit 21, the connection between the first end and the second end of the first switch S11 is turned on, the connection between the first end and the second end of the second switch S21 is turned on, and the first end of the third switch S31 is turned on. The connection between the terminal and the second terminal is disconnected, as shown in FIG. 3 , the connection between the first battery pack 11 and the bus bar is restored, and it is in series connection with other battery packs.

When the battery packs in the battery module are connected in parallel, when the battery packs in the battery module satisfy the conditions (a2), conditions (b2), conditions (c2), conditions (d2), and conditions (e2) When at least one condition is met, the connection between the first end and the second end of the first switch in the switch unit corresponding to the battery pack is turned on, and the connection between the first end and the third end of the second switch is Conduction, the connection between the battery pack and the busbar is conducted, and the battery pack is connected in parallel with other battery packs.

For example, as shown in FIG. 8 , if the first battery pack 11 satisfies at least one of the conditions (a2), conditions (b2), conditions (c2), conditions (d2), and conditions (e2), the control of the first battery The connection between the first end and the second end of the first switch S11 in the switch unit 21 is turned on, and the connection between the first end and the third end of the second switch S21 is turned on, as shown in FIG. The first battery pack 11 is connected to the bus bar and is connected in parallel with other battery packs.

It can be seen that through the above method, when a battery pack disconnected from the busbar meets the specified requirements, it can be restored to the busbar and connected to other battery packs in a specified manner, thereby ensuring that the system can still continue to work.

In a second aspect, an embodiment of the present application further provides an energy storage system. Please refer to FIG. 8 . The energy storage system includes an inverter unit 200 and the battery module 100 according to any one of the first aspect. The inverter unit is electrically connected to each battery pack through a bus bar. When the battery module includes the control unit, the control unit controls the on-off of the switch unit in response to the first indication signal of the inverter unit, and the first indication signal includes the type of the inverter unit.

Specifically, the inverter unit includes an energy storage inverter, or any other bidirectional AC/DC converter. In this energy storage system, by controlling the on-off of the switch unit, the battery packs can be connected in series or in parallel, and the connection mode between the battery packs can be flexibly switched to improve the compatibility and adaptation of the energy storage system. sex.

When the battery module includes a control unit, the control unit in the battery module is connected in communication with the inverter unit. When the inverter unit is a high-voltage inverter unit, the first indication signal will include the information that the inverter unit is a high-voltage inverter. , after the control unit receives the first indication signal, it will control the on-off of the switch in each switch unit to form a series connection between each battery pack. When the inverter unit is a low-voltage inverter unit, the first indication signal will include the information that the inverter unit is a low-voltage type. After the control unit receives the first instruction signal, it will control the on-off of the switch in each switch unit. disconnected to form a parallel connection between each battery pack.

In some embodiments, when the battery module includes the control unit, the inverter unit limits the bus current to the first current threshold in response to the second indication signal from the control unit.

Specifically, each time the battery module controls the on-off of the switch of the switch unit, in order to ensure the safety of the energy storage system, the control unit will send a second indication signal to the control unit before each control of the on-off of the switch. After the transformer unit receives the second indication signal, it will limit the current of the busbar, for example, to limit the current to 0A, so as to ensure the working reliability and safety of the system. In addition, after the switch unit is switched on and off, the control unit also sends a third instruction signal to the control unit, and the inverter unit restores the bus current after receiving the third instruction signal. In practical applications, the first current threshold may also be other suitable current values, which need not be limited to the limitations in this embodiment.

In some embodiments, the energy storage system further includes a DCDC unit. Wherein, the inverter unit is connected to the bus bar through the DCDC unit. In the battery module, by setting the DCDC unit, the magnitude of the DC voltage output from the inverter unit to the busbar can be changed, or the magnitude of the DC voltage output from the busbar voltage to the inverter unit can be changed, so as to ensure the normal operation of the energy storage system, and The energy storage system can meet different application scenarios and improve the adaptability of the energy storage system.

For example, when the battery packs in the energy storage system are connected in series, when the connection between the battery pack and the bus is disconnected, the total voltage between the battery packs will drop. At this time, in order to ensure the normal operation of the energy storage system, control the The DCDC unit adjusts the operating voltage of the system. Specifically, if the energy storage system is in the charging state at this time, the DCDC unit should reduce the voltage output from the inverter unit to the busbar. If the energy storage system is in the discharging state, the DCDC unit should increase the output of the busbar to the inverter unit. voltage, so as to ensure the normal operation of the energy storage system.

An embodiment of the present application provides a battery module and an energy storage system, including: at least two battery packs and at least two switch units; the switch units are configured to be connected to the battery packs in a one-to-one correspondence; the switch unit includes a first switch , a second switch and a third switch; the first end of the first switch is coupled to the positive pole of the battery pack, the second end of the first switch and the busbar are coupled to the first connection point, and the first end of the second switch is coupled to the battery pack The negative pole of the second switch, the second end of the second switch and the busbar are coupled to the second connection point, the third end of the second switch is coupled to the busbar, and the third switch is arranged between the first connection point and the second connection point. By controlling the on or off of the first switch, the second switch and the third switch in each switch unit, the series connection mode or parallel connection mode can be freely switched between multiple battery packs, thereby improving the performance of the energy storage system. compatibility.

It should be noted that the device embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physically separated unit, that is, it can be located in one place, or it can be distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; under the thinking of the present application, the technical features in the above embodiments or different embodiments can also be combined, The steps may be carried out in any order, and there are many other variations of the different aspects of the present application as described above, which are not provided in detail for the sake of brevity; although the present application has been The skilled person should understand that it is still possible to modify the technical solutions recorded in the foregoing embodiments, or to perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the implementation of the application. scope of technical solutions.

Claims (12)

1. A battery module, comprising:

at least two battery packs;

at least two switch units configured to be connected in one-to-one correspondence with the battery packs;

the switching unit includes a first switch, a second switch, and a third switch;

a first terminal of the first switch is coupled to an anode of the battery pack, a second terminal of the first switch and a bus are coupled to a first connection point, a first terminal of the second switch is coupled to a cathode of the battery pack, a second terminal of the second switch and the bus are coupled to a second connection point, a third terminal of the second switch is coupled to the bus, and the third switch is disposed between the first connection point and the second connection point.

2. The battery module according to claim 1, wherein the second switch comprises a first sub-switch and a second sub-switch;

the first and second sub-switches are coupled in parallel between a negative pole of the battery pack and the bus bar.

3. The battery module according to claim 1 or 2, wherein the circuit further comprises:

and the control unit is configured to control the on-off of the switch units so as to form series connection or parallel connection between the battery packs.

4. The battery module according to claim 3, wherein when the first switches are turned on, the third switches are turned off, and the first ends and the second ends of the second switches are turned on, the battery packs are connected in series.

5. The battery module according to claim 3, wherein when the first switches are turned on, the third switches are turned on, and the first terminals and the third terminals of the second switches are turned on, the battery packs are connected in parallel.

6. The battery module according to claim 3, wherein the connection between the corresponding battery pack and the bus bar is disconnected when any battery pack satisfies at least one of the following conditions:

(a1) the absolute value of the voltage difference between the voltage of the battery pack and the average voltage of the battery pack exceeds a first threshold range, or the absolute value of the voltage difference between the voltage of the battery pack and the maximum value of the voltage of the battery pack exceeds a second threshold range;

(b1) the absolute value of the SOC difference between the SOC of the battery pack and the average SOC of the battery pack exceeds a third threshold range, or the absolute value of the SOC difference between the SOC of the battery pack and the SOC of the battery pack exceeds a fourth threshold range;

(c1) the battery pack is malfunctioning;

(d1) the absolute value of the temperature difference between the temperature of the battery pack and the average temperature of the battery pack exceeds a fifth threshold range, or the temperature of the battery pack exceeds a first temperature threshold;

(e1) and the absolute value of the SOH difference between the SOH of the battery pack and the average SOH of the battery pack exceeds a sixth threshold range, or the absolute value of the SOH difference between the SOH of the battery pack and the SOH of the battery pack exceeds a seventh threshold range.

7. The battery module according to claim 6, wherein the disconnecting corresponding to the connection of the battery pack to the bus bar comprises:

disconnecting the first switch, disconnecting the connection between the first and second ends of the second switch, such that the battery packs in the series connection are disconnected from the bus bar;

or,

disconnecting the first switch and disconnecting the first terminal and the third terminal of the second switch to disconnect the battery packs in the parallel connection from the bus bar.

8. The battery module according to claim 3, wherein after the battery pack is disconnected from the bus bar, the connection of the battery pack to the bus bar is restored when at least one of the following conditions is satisfied:

(a2) the absolute value of the voltage difference between the voltage of the battery pack and the average voltage of the battery pack does not exceed a first threshold range, or the absolute value of the voltage difference between the voltage of the battery pack and the maximum value of the voltage of the battery pack does not exceed a second threshold range;

(b2) the absolute value of the SOC difference between the SOC of the battery pack and the average SOC of the battery pack is not more than a third threshold range, or the absolute value of the SOC difference between the SOC of the battery pack and the SOC of the battery pack is not more than a fourth threshold range;

(c2) the battery pack is a normal battery pack for replacing a fault battery pack;

(d2) the absolute value of the temperature difference between the temperature of the battery pack and the average temperature of the battery pack does not exceed a fifth threshold range, or the temperature of the battery pack does not exceed a first temperature threshold;

(e2) and the absolute value of the SOH difference between the SOH of the battery pack and the average SOH of the battery pack does not exceed a sixth threshold range, or the absolute value of the SOH difference between the SOH of the battery pack and the SOH of the battery pack is not more than a seventh threshold range.

9. The battery module of claim 8, wherein the restoring the connection of the battery pack to the bus bar comprises:

turning on a first switch, turning on a connection between a first terminal and a second terminal of a second switch, and turning off a third switch to restore the connection of the battery packs in series connection with the bus bar;

or,

and conducting the first switch, conducting the connection between the first end and the third end of the second switch, and conducting the third switch, so that the battery packs in parallel connection are restored to be connected with the bus.

10. An energy storage system, comprising: an inverter unit, and the battery module according to any one of claims 1 to 9;

the inversion unit is electrically connected with each battery pack through a bus;

when the battery module comprises a control unit, the control unit responds to a first indication signal of the inversion unit to control the on-off of the switch unit, and the first indication signal comprises the type of the inversion unit.

11. The energy storage system of claim 10, wherein when the battery module includes a control unit, the inverter unit is responsive to a second indication signal from the control unit to limit the bus current to a first current threshold.

12. The energy storage system of claim 10 or 11, further comprising a DCDC unit;

the inversion unit is connected with the bus through the DCDC unit.

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