CN114300764A

CN114300764A - Battery module and energy storage system

Info

Publication number: CN114300764A
Application number: CN202111581523.6A
Authority: CN
Inventors: 杨朝
Original assignee: Dongguan Poweramp Technology Ltd
Current assignee: Dongguan Poweramp Technology Ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-04-08
Anticipated expiration: 2041-12-22
Also published as: CN114300764B

Abstract

The embodiment of the application provides a battery module and energy storage system, includes: at least two battery packs and at least two switch units; the switch units are configured to be connected with the battery packs in a one-to-one correspondence manner; the switch unit comprises a first switch, a second switch and a third switch; the first end of the first switch is coupled to the anode of the battery pack, the second end of the first switch and the bus are coupled to the first connection point, the first end of the second switch is coupled to the cathode of the battery pack, the second end of the second switch and the bus are coupled to the second connection point, the third end of the second switch is coupled to the bus, and the third switch is arranged between the first connection point and the second connection point. By controlling the connection or disconnection of the first switch, the second switch and the third switch in each switch unit, the series connection mode or the parallel connection mode can be freely switched among the plurality of battery packs, and therefore the compatibility of the energy storage system is improved.

Description

Battery module and energy storage system

Technical Field

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

Background

With the development of intelligent control technology, developed industrial countries have established smart power grids as important strategic measures to seize the future low-carbon economic high-point. The energy storage technology is used as a key link of the smart power grid, and the functions of peak clipping, valley filling and stable access to new energy make the smart power grid have wide application prospects in a power system.

The energy storage system is a core device in the energy storage technology, and the connection mode switching between the battery packs in the existing energy storage system is not flexible, the application scene is single, and the compatibility is poor.

Disclosure of Invention

The embodiment of the application provides a battery module and an energy storage system to flexibly switch the connection mode between 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 switching units. Each switch unit is configured to be connected in one-to-one correspondence with each battery pack. Each of the switching units includes a first switch, a second switch, and a third switch. The first end of the first switch is coupled to the anode of the battery pack, the second end of the first switch and the bus are coupled to the first connection point, the first end of the second switch is coupled to the cathode of the battery pack, the second end of the second switch and the bus are coupled to the second connection point, the third end of the second switch is coupled to the bus, and the third switch is arranged between the first connection point and the second connection point. The plurality of switch units are correspondingly connected with the plurality of battery packs, so that the switches in the switch units can be controlled, the connection condition of each battery pack and the bus is changed, and the serial/parallel connection mode of each battery pack is flexibly switched.

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

In some embodiments, the circuit further comprises 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 each battery pack.

In some embodiments, when the first switch of each switch unit is turned on, the third switch of each switch unit is turned off, and the first end and the second end of the second switch of each switch unit are turned on, the battery packs are connected in series. The battery packs may be connected in a series connection by controlling the switching state of each switch in the switching unit.

In some embodiments, when the first switch of each switch unit is turned on, the third switch of each switch unit is turned on, and the first terminal and the third terminal of the second switch of each switch unit are turned on, the battery packs are connected in parallel. The battery packs may be connected in a parallel connection by controlling the switching state of each switch in the switching unit.

In some embodiments, when any of the battery packs satisfies at least one of the condition (a1), the condition (b1), the condition (c1), the condition (d1), and the 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 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. Condition (b1) is: 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. Condition (c1) is: the battery pack malfunctions. Condition (d1) is: 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. Condition (e1) is: 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 maximum SOH of the battery pack exceeds a seventh threshold range.

Through when a certain battery package takes place unusually, with its disconnection with the generating line, improve the security and the reliability of battery module at the during operation, simultaneously, and reduce the maintenance degree of difficulty to the battery package.

In some embodiments, disconnecting the corresponding battery pack from the bus bar includes: disconnecting the first switch and the first end and the second end of the second switch so as to disconnect the battery packs in series connection from the bus; or disconnecting the first switch and disconnecting the first end and the third end of the second switch so as to disconnect the battery packs in parallel connection from the bus. Therefore, when a certain battery pack does not meet the specified requirements, the connection between the certain battery pack and the bus can be disconnected, and other battery packs are still in a normal connection mode, so that the system can still continue to work.

In some embodiments, 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 condition (a2), the condition (b2), the condition (c2), the condition (d2), and the condition (e2) is satisfied. Wherein the condition (a2) is: 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. Condition (b2) is: the absolute value of the SOC difference between the SOC of the battery pack and the average SOC of the battery pack does not exceed 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 does not exceed a fourth threshold range. Condition (c2) is: the battery pack is a normal battery pack that replaces a failed battery pack. Condition (d2) is: 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 the range of the fifth threshold value, or the temperature of the battery pack does not exceed the first temperature threshold value. Condition (e2) is: 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 the sixth threshold range, or the absolute value of the SOH difference between the SOH of the battery pack and the most significant value of the SOH of the battery pack does not exceed the seventh threshold range.

After a certain battery pack is disconnected from the bus, when the parameters of the battery pack are recovered within the specified required range, the battery pack can be reconnected with the bus, so that the safety and the reliability of the battery module in working can be improved, and the convenience of maintenance is improved.

In some embodiments, restoring the connection of the battery pack to the bus bar comprises: turning on the first switch, turning on the connection between the first and second ends of the second switch, and turning off the third switch to restore the connection of the battery packs in the series connection to the bus; or, the first switch is turned on, the connection between the first end and the third end of the second switch is turned on, and the third switch is turned on, so that the battery packs in parallel connection are restored to be connected with the bus. Therefore, when a certain battery pack disconnected from the bus meets the specified requirement, the battery pack is restored to be connected with the bus and is in the specified connection mode with other battery packs, and therefore 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 inversion unit is electrically connected with each battery pack through a bus. When the battery module comprises the control unit, the control unit responds to a first indication signal of the inversion unit and controls the switch unit to be switched on and switched off, and the first indication signal comprises the type of the inversion unit. Thus, the convenience and the adaptability of the energy storage system are improved.

In some embodiments, when the battery module comprises the control unit, the inverter unit responds to the second indication signal of the control unit and limits the bus current to the first current threshold value, so that the working reliability and safety of the energy storage system are ensured.

In some embodiments, the energy storage system further comprises a DCDC unit. The inversion unit is connected with the bus through the DCDC unit, and the adaptability of the energy storage system is improved.

Compared with the prior art, the beneficial effects of one or more embodiments of the present application include: being different from the situation of the prior art, the 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 with the battery packs in a one-to-one correspondence manner; the switch unit comprises a first switch, a second switch and a third switch; the first end of the first switch is coupled to the anode of the battery pack, the second end of the first switch and the bus are coupled to the first connection point, the first end of the second switch is coupled to the cathode of the battery pack, the second end of the second switch and the bus are coupled to the second connection point, the third end of the second switch is coupled to the bus, and the third switch is arranged between the first connection point and the second connection point. By controlling the connection or disconnection of the first switch, the second switch and the third switch in each switch unit, the series connection mode or the parallel connection mode can be freely switched among the plurality of battery packs, and therefore the compatibility of the energy storage system is improved.

Drawings

One or more embodiments are illustrated by the accompanying figures in the drawings that correspond thereto and are not to be construed as limiting the embodiments, wherein elements/modules and steps having the same reference numerals are represented by like elements/modules and steps, unless otherwise specified, and the drawings are not to scale.

Fig. 1 is a schematic structural diagram of a battery module according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a connection of FIG. 1;

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

fig. 4 is a schematic structural diagram of another battery module provided in the embodiment of the present application;

FIG. 5 is a schematic illustration of a connection of FIG. 4;

FIG. 6 is another connection schematic of FIG. 4;

FIG. 7 is a further schematic illustration of the connection of FIG. 1;

FIG. 8 is a further schematic illustration of the connection of FIG. 1;

fig. 9 is a schematic structural diagram of an energy storage system according to an embodiment of the present application.

Detailed Description

The present application will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present application, but are not intended to limit the present application in any way. It should be noted that various changes and modifications can be made by one skilled in the art without departing from the spirit of the application. All falling within the scope of protection of the present application.

In order to facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and specific embodiments. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

It should be noted that, if not conflicted, the various features of the embodiments of the present application may be combined with each other within the scope of protection of the present application. In addition, although the functional blocks are divided in the device diagram, in some cases, the blocks may be divided differently from those in the device. Further, the terms "first," "second," and the like, as used herein, do not limit the data and the execution order, but merely distinguish the same items or similar items having substantially the same functions and actions.

In recent years, energy conservation and environmental protection are vigorously advocated by the nation, an energy storage system can carry out peak clipping and valley filling on a power grid, and power resource supplement and regulation are provided for intelligent city and intelligent building construction. The energy storage system can be connected with a load/power grid, so that when the energy storage system is connected with the power grid, electric energy in the power grid can charge the energy storage system, and when the energy storage system is connected with the load, the electric energy stored in the energy storage system can discharge for the load, so that the energy storage system serves as a standby power supply.

The energy storage system comprises a battery module and an inversion unit, wherein the battery module comprises a plurality of battery packs, and in one implementation mode of the battery module, the plurality of battery packs are connected in a fixed connection mode. For example, the plurality of battery packs are connected to each other in a fixed series connection manner or in a fixed parallel connection manner. When the connection mode among the battery packs needs to be switched, the connection mode among the battery packs needs to be switched through manually replacing the wiring mode.

In addition, in the battery module in the fixed connection mode, if a certain battery pack fails and cannot work, the whole system is immediately in a paralyzed state, and if the normal work of the system needs to be recovered, the failed battery pack needs to be immediately replaced, so that the maintenance difficulty of the whole system is increased. Moreover, if the voltage difference between the battery packs needs to be balanced, the voltage difference between the battery packs cannot be balanced automatically, and extra auxiliary equipment is often needed for balancing.

The embodiment of the application also provides an implementation mode of the battery module, in the battery module, a plurality of switch units are arranged to be correspondingly connected with a plurality of battery packs, the switch units are correspondingly arranged between the battery packs and the bus, and for each battery pack, the connection condition of each battery pack and the bus can be changed by switching on or off each switch in the switch units. Therefore, the connection mode among the battery packs can be freely switched, when a certain battery pack breaks down, the system can be immediately adjusted, the system can continuously maintain normal operation, and the problem of difficult balance among the battery packs can be solved.

Referring to fig. 1, the battery module 100 includes: at least two battery packs and at least two switching units. Wherein each switch unit is configured to be connected with each battery pack in a one-to-one correspondence. Each of the switching units includes a first switch, a second switch, and a third switch. The first end of the first switch is coupled to the anode of the battery pack, the second end of the first switch and the bus are coupled to the first connection point, the first end of the second switch is coupled to the cathode of the battery pack, the second end of the second switch and the bus are coupled to the second connection point, the third end of the second switch is coupled to the bus, and the third switch is arranged between the first connection point and the second connection point.

Fig. 1 shows a first battery pack 11, a second battery pack 12, a first switching unit 21, and a second switching unit 22. The first battery pack 11 is correspondingly connected to the first switch unit 21, 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 correspondingly connected to the second switch unit 22, and the second switch unit 22 includes a first switch S12, a second switch S22 and a third switch S32.

The battery pack may include only one battery cell, or may include at least two battery cells connected in series and/or in parallel. A switch refers to an electronic component having at least two states of on (on) and off (off) so that an element connected across the switch can be switched between the two states of connection and disconnection. Specifically, the switch may include at least one of a transistor, a field effect transistor, an insulated gate bipolar transistor, a relay, and the like, which has at least two different states of "on" and "off" and is an electrical component capable of performing a switching function.

Specifically, in the battery module 100, a plurality of switch units are provided to be connected to a plurality of battery packs, and the switch units are correspondingly provided between the battery packs and the bus bars, so that, for each battery pack, the connection condition of each battery pack to the bus bar can be changed by turning on or off the first switch, the second switch, and the third switch in the switch units.

Through the mode, each battery pack can be connected in series, or each battery pack can be connected in parallel, so that the serial/parallel connection mode of each battery pack can be flexibly switched, different requirements can be met, and the compatibility and the adaptability of the battery module are improved. In addition, the switch state of a certain switch unit can be controlled to disconnect a certain battery pack from the bus and ensure the normal connection between other battery packs, or the disconnected battery pack is recovered to be connected with the bus, so that the switch state in the switch unit is controlled to flexibly disconnect one or more battery packs from the bus or recover the connection between one or more battery packs and the bus, and the battery packs can be subsequently used for realizing the balance among batteries or eliminating faults, the convenience and flexibility of replacement of the battery packs are improved, the difficulty of after-sale maintenance is reduced, and the use experience of users is improved.

In some embodiments, with continued reference to fig. 1, the battery module 100 further includes a positive terminal P + and a negative terminal P-, in each switch unit, a first end of the first switch is connected to a positive electrode of the battery pack, a second end of the first switch and the positive bus bar are connected to the first connection point, a first end of the second switch is connected to a negative electrode of the battery pack, a second end of the second switch and the positive bus bar are connected to the second connection point, a third end of the second switch is connected to the negative bus bar, a first end of the third switch is connected to the first connection point, and a second end of the third switch is connected to the second connection point.

In the battery module, each battery pack is connected with the bus through the corresponding switch unit, so that each battery pack can be connected in series or in parallel by controlling the switch state of each switch unit subsequently, the connection mode between the battery packs can be freely switched, and the compatibility and the adaptability are improved. In addition, the connection between a certain battery pack and the bus can be independently controlled to be connected or disconnected, so that the certain battery pack is cut out or into the whole system, the normal work of other battery packs is not influenced, and the difficulty of after-sale maintenance is reduced.

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

For example, referring to fig. 2, in the battery module, as for the first switching unit 21, the connection between the first terminal and the second terminal of the first switch S11 is turned on, the connection between the first terminal and the second terminal of the third switch S31 is turned off, and the connection between the first terminal and the second terminal of the second switch S21 is turned on; with the second switch unit 22, the connection between the first terminal and the second terminal of the first switch S12 is conductive, the connection between the first terminal and the second terminal of the third switch S32 is open, and the connection between the first terminal and the second terminal of the second switch S22 is conductive. Thus, for each battery pack, the positive pole of the battery pack is connected to the bus bar at the first connection point, the negative pole of the battery pack is connected to the bus bar at the second connection point, and a series connection is formed between the battery packs. It can be seen that the battery packs can be connected in a series connection by controlling the switching state of each switch in the switching unit.

In some embodiments, when the first switch of each switch unit is turned on, the third switch of each switch unit is turned on, and the first terminal and the third terminal of the second switch of each switch unit are turned on, the battery packs are connected in parallel.

For example, referring to fig. 3, in the battery module, as for the first switching unit 21, the connection between the first terminal and the second terminal of the first switch S11 is turned on, the connection between the first terminal and the second terminal of the third switch S31 is turned on, and the connection between the first terminal and the third terminal of the second switch S21 is turned on; for the second switching unit 22, the connection between the first terminal and the second terminal of the first switch S12 is conductive, the connection between the first terminal and the second terminal of the third switch S32 is conductive, and the connection between the first terminal and the third terminal of the second switch S22 is conductive. Thus, for each battery pack, the positive poles of the battery packs are connected to the positive terminal P +, the negative poles of the battery packs are connected to the negative terminal P-, and a parallel connection is formed between the battery packs. It can be seen that the battery packs can be connected in a parallel connection manner by controlling the switching state of each switch in the switching unit.

In summary, the battery module provided in the embodiment of the present application can flexibly switch the series connection or the parallel connection of the battery packs by controlling the on/off of each switch in the switch unit, thereby improving the compatibility of the battery module, satisfying different application scenarios, and improving the adaptability of the battery module.

In some embodiments, the second switch includes a first sub-switch and a second sub-switch. Wherein the first and second sub-switches 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, a first end of the first sub-switch S211 and a first end of the second sub-switch S212 are both connected to the negative electrode of the first battery pack 11, a second end of the first sub-switch S211 and the bus bar are connected to a second connection point, and a second end of the second sub-switch S212 is connected to the negative electrode terminal P-.

In the battery module, referring to fig. 5, when the connection between the first end and the second end of the first switch, the connection between the first end and the second end of the third switch, the connection between the first end and the second end of the first sub-switch, and the connection between the first end and the second end of the second sub-switch of each switch unit are turned on, the negative electrode of the battery pack is connected to the positive electrode terminal P +, and the battery packs are connected in series. Referring to fig. 6, when the connection between the first terminal and the second terminal of the first switch is turned on, the connection between the first terminal and the second terminal of the third switch is turned on, the connection between the first terminal and the second terminal of the first sub-switch is turned off, and the connection between the first terminal and the second terminal of the second sub-switch is turned on, the positive electrode of each battery pack is connected to the positive electrode terminal P +, the negative electrode of each battery pack is connected to the negative electrode terminal P-, and the battery packs are connected in parallel. It can be seen that the series/parallel connection between the battery packs can be switched by controlling the turn-on or turn-off of the first switch, the second switch, the first sub-switch, and the second sub-switch.

In some embodiments, the circuit further comprises: 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 each have at least one control end, the control end of each switch is connected to the control unit, and each switch can be correspondingly switched between on and off states according to different control signals of the control unit. The control unit may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a single chip, an arm (acorn RISC machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. The control unit can be used for outputting a control signal to the control end of each switch, so that the on-off state of each switch in the switch unit is controlled, and the connection condition between the battery pack and the bus is realized.

Specifically, the battery module may include only one control unit, and the control unit is connected to the control end of each switch unit, and outputs a control signal to each switch through different output ports. When the number of the switches is large, in order to facilitate management, the battery module may also be provided with a plurality of control units, wherein the number of the control units is equal to the number of the battery packs, each control unit is correspondingly connected with each switch unit, and the on-off state of each switch can also be controlled. In practical application, the number of the control units may be set according to actual needs, and is not limited herein.

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 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.

Specifically, a voltage value of each battery pack which is connected and conducted with the bus is obtained; then, calculating to obtain the average voltage of the battery pack connected and conducted with the bus; then, the voltage value of each battery pack which is connected and conducted with the bus is subtracted from the average voltage, and an absolute value is taken to obtain a voltage difference absolute value corresponding to each battery pack which is connected and conducted with the bus; and judging whether the absolute value of the voltage difference exceeds a first threshold range one by one, and disconnecting the battery pack from the bus if the absolute value of the voltage difference corresponding to a certain battery pack exceeds the first threshold range.

Or when each battery pack is in a discharging state, the voltage value of each battery pack which is connected and conducted with the bus is acquired; then, obtaining the maximum voltage value of the battery pack connected and conducted with the bus; then, the voltage value of each battery pack which is connected and conducted with the bus is subtracted from the maximum voltage value of the battery pack, and the absolute value is obtained to obtain the absolute value of the voltage difference corresponding to each battery pack which is connected and conducted with the bus; and judging whether the absolute value of the voltage difference exceeds a second threshold range one by one, and disconnecting the battery pack from the bus if the absolute value of the voltage difference corresponding to a certain battery pack exceeds the second threshold range.

Or when each battery pack is in a charging state, acquiring the voltage value of each battery pack which is connected and conducted with the bus; then, obtaining the minimum voltage value of the battery pack connected and conducted with the bus; then, the voltage value of each battery pack which is connected and conducted with the bus is subtracted from the minimum voltage value of the battery pack, and an absolute value is taken to obtain a voltage difference absolute value corresponding to each battery pack which is connected and conducted with the bus; and judging whether the absolute value of the voltage difference exceeds a second threshold range one by one, and disconnecting the battery pack from the bus if the absolute value of the voltage difference corresponding to a certain battery pack exceeds the second threshold range.

The absolute value of the voltage difference between the voltage of the battery pack and the average voltage of the battery pack 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 is judged, the battery pack with the absolute value of the voltage difference exceeding a first threshold range or a second threshold range is disconnected from the bus, the voltage between the battery packs connected and conducted with the bus is ensured to meet the specified requirements, and therefore the battery module works under the normal condition.

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 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.

Specifically, after the connection between the battery pack and the bus is disconnected, the voltage value of each battery pack can be obtained first; then, calculating to obtain the average voltage of the battery pack; then, the voltage value of the battery pack disconnected with the bus is subtracted from the average voltage, and the absolute value is obtained to obtain the absolute value of the voltage difference corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the voltage difference does not exceed a first threshold range, and if the absolute value of the voltage difference corresponding to the battery pack does not exceed the first threshold range, re-conducting the connection between the battery pack and the bus.

Or when each battery pack is in a discharging state, acquiring the voltage value of each battery pack after the battery pack is disconnected with the bus; then, obtaining the maximum voltage value of the battery pack; then, the voltage value of the battery pack disconnected with the bus is subtracted from the maximum voltage value of the battery pack, and an absolute value is obtained to obtain a voltage difference absolute value corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the voltage difference does not exceed the second threshold range one by one, and if the absolute value of the voltage difference corresponding to a certain battery pack does not exceed the second threshold range, re-connecting the battery pack with the bus.

Or when each battery pack is in a charging state, acquiring the voltage value of each battery pack after the battery pack is disconnected with the bus; then, obtaining the minimum voltage value of the battery pack; then, the voltage value of the battery pack disconnected with the bus is subtracted from the minimum voltage value of the battery pack, and an absolute value is taken to obtain a voltage difference absolute value corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the voltage difference does not exceed a second threshold range, and if the absolute value of the voltage difference corresponding to the battery pack does not exceed the second threshold range, re-conducting the connection between the battery pack and the bus.

And after the connection between the battery pack and the bus is disconnected, the battery pack of which the absolute value does not exceed the first threshold range or the second threshold range is restored to be connected with the bus by judging the absolute value of the voltage difference between the voltage of the battery pack and the average voltage of the battery pack or judging 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. Therefore, when the absolute value of the voltage difference of the battery pack does not accord with the specification, the connection between the battery pack and the bus can be disconnected, and when the absolute value of the voltage difference of the battery pack accords with the specification, the battery pack is connected with the bus and then conducted.

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 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.

The SOC is a state of charge of the battery pack, and may be used to reflect a remaining capacity of the battery pack. Specifically, the SOC of each battery pack which is connected and conducted with a bus is obtained firstly; then, calculating to obtain the average SOC of the battery packs connected and communicated with the bus, and then, subtracting the SOC value of each battery pack connected and communicated with the bus from the average SOC and taking an absolute value to obtain an SOC difference absolute value corresponding to each battery pack connected and communicated with the bus; and judging whether the absolute value of the SOC difference exceeds a third threshold range one by one, and disconnecting the battery pack from the bus if the absolute value of the SOC difference corresponding to a certain battery pack exceeds the third threshold range.

Or when each battery pack is in a discharging state, firstly acquiring the SOC value of each battery pack which is connected and conducted with the bus; then, obtaining the maximum SOC value of the battery pack connected and conducted with the bus; then, the SOC value of each battery pack which is connected and conducted with the bus is subtracted from the maximum SOC value of the battery pack, and an absolute value is obtained; and judging whether the absolute value of the SOC difference exceeds a fourth threshold range one by one, and disconnecting the battery pack from the bus if the absolute value of the SOC difference corresponding to a certain battery pack exceeds the fourth threshold range.

Or when each battery pack is in a charging state, firstly acquiring the SOC value of each battery pack which is connected and communicated with the bus; then, obtaining the minimum SOC value of the battery pack connected and conducted with the bus; then, the SOC value of each battery pack which is connected and communicated with the bus is subtracted from the minimum SOC value of the battery pack, and an absolute value is taken to obtain the SOC difference absolute value corresponding to each battery pack which is connected and communicated with the bus; and judging whether the absolute value of the SOC difference exceeds a fourth threshold range one by one, if the absolute value of the SOC difference corresponding to a certain battery pack exceeds the fourth threshold range, disconnecting the battery pack from the bus, and disconnecting the battery pack from the bus.

The connection between the battery pack with the SOC difference absolute value exceeding the third threshold range or the fourth threshold range and the bus is disconnected by judging the SOC difference absolute value between the SOC of the battery pack and the average SOC of the battery pack or judging the SOC difference absolute value between the SOC of the battery pack and the SOC of the battery pack at the maximum value, so that the SOC between the battery packs under the working system meets the specified requirements, and the battery module works under the normal condition.

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

Specifically, after the connection between the battery pack and the bus is disconnected, the SOC of each battery pack is obtained; then, calculating to obtain the average SOC of the battery pack, and then, subtracting the SOC value of the battery pack disconnected with the bus from the average SOC and taking an absolute value to obtain an SOC difference absolute value corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the SOC difference does not exceed a third threshold range, and if the absolute value of the SOC difference corresponding to the battery pack does not exceed the third threshold range, re-conducting the connection between the battery pack and the bus.

Or when each battery pack is in a discharging state, firstly acquiring the SOC value of each battery pack; then, obtaining the maximum SOC value of the battery pack; then, the SOC value of the battery pack disconnected with the bus is subtracted from the maximum SOC value of the battery pack, and an absolute value is taken to obtain an SOC difference absolute value corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the SOC difference does not exceed the range of a fourth threshold value, and if the absolute value of the SOC difference corresponding to the battery pack does not exceed the range of the fourth threshold value, re-conducting the connection between the battery pack and the bus.

Or when each battery pack is in a charging state, acquiring the SOC value of each battery pack; then, obtaining the minimum SOC value of the battery pack; then, the SOC value of the battery pack disconnected with the bus is subtracted from the minimum SOC value of the battery pack, and an absolute value is taken to obtain the SOC difference absolute value of the battery pack disconnected with the bus; and judging whether the absolute value of the SOC difference does not exceed the range of a fourth threshold value, and if the absolute value of the SOC difference corresponding to the battery pack does not exceed the range of the fourth threshold value, re-conducting the connection between the battery pack and the bus.

And recovering the connection between the battery pack of which the SOC difference absolute value does not exceed the third threshold range or the fourth threshold range and the bus by judging the SOC difference absolute value between the SOC of the battery pack disconnected with the bus and the average SOC of the battery pack or judging the SOC difference absolute value between the SOC of the battery pack disconnected with the bus and the SOC maximum value of the battery pack, and conducting the connection between the battery pack of which the SOC difference absolute value does not exceed the third threshold range or the fourth threshold range and the bus again. Therefore, when the absolute value of the SOC difference between the battery packs does not accord with the specification, the connection between the battery packs and the bus can be disconnected, and when the absolute value of the SOC difference between the battery packs accords with the specification, the battery packs are connected and connected with the bus, so that the function of balance avoidance between the 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 malfunctions.

Specifically, when an abnormality such as a liquid leakage or a voltage abnormality occurs in one or more battery packs connected to and electrically connected to the bus bar, the connection between the battery packs and the bus bar is disconnected. Through the mode with the disconnection of being connected of trouble battery package and generating line, not only make things convenient for the maintenance technical personnel to maintain trouble battery package, guarantee battery module normal work moreover.

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 a failed battery pack.

Specifically, when the connection between the faulty battery pack and the bus is disconnected, the faulty battery pack can be replaced by the normal battery pack, and when the faulty battery pack is replaced by the normal battery pack, the connection between the battery pack and the bus is recovered, so that the maintenance convenience is improved.

In some embodiments, when the battery pack satisfies the condition (d1), the battery pack is disconnected from the bus bar. Wherein, condition (d 1): 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.

Specifically, the temperature of each battery pack which is connected and conducted with the bus is obtained firstly; then, calculating to obtain the average temperature of the battery pack connected and conducted with the bus; then, the temperature value of each battery pack which is connected and communicated with the bus is differed from the average temperature, and the absolute value is taken to obtain the absolute value of the temperature difference corresponding to each battery pack which is connected and communicated with the bus; and judging whether the absolute value of the temperature difference exceeds the third threshold range one by one, and disconnecting the battery pack from the bus if the absolute value of the temperature difference corresponding to a certain battery pack exceeds the fifth threshold range.

Or, the temperature of each battery pack connected and conducted with the bus is acquired first, and then it is determined whether the temperature of each battery pack connected and conducted with the bus exceeds a first temperature threshold, for example, whether the temperature exceeds 100 ℃, and if the temperature exceeds the first temperature threshold, the connection between the battery pack and the bus is disconnected.

Through the mode, the temperature of the battery pack can be guaranteed to be kept to work under the specified requirement, and therefore the safety and reliability of the battery module can be improved.

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 temperature of the battery pack and the average temperature of the battery pack does not exceed the range of the fifth threshold value, or the temperature of the battery pack does not exceed the first temperature threshold value.

Specifically, after a battery pack is disconnected from a bus, the temperature of each battery pack is acquired; then, calculating to obtain the average temperature of each battery pack; then, the temperature value of the battery pack disconnected with the bus is subtracted from the average temperature, and the absolute value is taken to obtain the absolute value of the temperature difference corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the temperature difference does not exceed a fifth threshold range, and if the absolute value of the temperature difference does not exceed the fifth threshold range, re-conducting the connection between the battery pack and the bus.

Or, the temperature of each battery pack disconnected from the bus is acquired first, and then it is determined whether the temperature of each battery pack disconnected from the bus does not exceed a first temperature threshold, for example, whether the temperature exceeds 100 ℃, and if the temperature does not exceed the first temperature threshold, the connection between the battery pack and the bus is reconnected.

Through the mode, the bus can be reconnected when the temperature of the battery pack is recovered to the specified range, so that the safety and the reliability of the battery module are ensured.

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 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 maximum SOH of the battery pack exceeds a seventh threshold range.

The SOH is a quantitative indicator of the battery state of health of the battery pack, and can be used for reflecting the battery state of health of the battery pack. Specifically, the SOH of each battery pack which is connected and conducted with the bus is firstly obtained; then, calculating to obtain the average SOH of the battery pack connected and conducted with the bus; then, the SOH value of each battery pack which is connected and conducted with the bus is subtracted from the average SOH value, and the absolute value is obtained; obtaining an SOH difference absolute value corresponding to each battery pack which is connected and conducted with the bus; and judging whether the absolute value of the SOH difference exceeds the range of the sixth threshold value one by one, and disconnecting the battery pack from the bus if the absolute value of the SOH difference corresponding to a certain battery pack exceeds the range of the sixth threshold value.

Or, firstly, obtaining the SOH value of each battery pack which is connected and conducted with the bus; then, obtaining the maximum SOH value of the battery pack connected and conducted with the bus; then, the SOH value of each battery pack which is connected and conducted with the bus is subtracted from the maximum SOH value of the battery pack, and the absolute value is obtained to obtain the SOH difference absolute value corresponding to each battery pack which is connected and conducted with the bus; and judging whether the absolute value of the SOH difference exceeds the seventh threshold range one by one, and if the absolute value of the SOH difference corresponding to a certain battery pack exceeds the seventh threshold range, disconnecting the battery pack from the bus.

Through the mode, the battery pack with the relatively poor battery health state of the battery module can be disconnected with the bus, so that the working efficiency of the battery module can be improved, and the safety of the battery module during working can be ensured.

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 SOH of the battery pack and the average SOH of the battery pack does not exceed the sixth threshold range, or the absolute value of the SOH difference between the SOH of the battery pack and the most significant value of the SOH of the battery pack does not exceed the seventh threshold range.

Specifically, after the connection between the battery pack and the bus is disconnected, the SOH of each battery pack is obtained; then, calculating to obtain the average SOH of the battery pack; then, the SOH value of the battery pack disconnected with the bus is subtracted from the average SOH value, and an absolute value is obtained to obtain an SOH difference absolute value corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the SOH difference does not exceed a sixth threshold range, and if the absolute value of the SOH difference does not exceed the sixth threshold range, re-conducting the connection between the corresponding battery pack and the bus.

Or when the connection between the battery pack and the bus is disconnected, the SOH value of each battery pack is obtained; then, obtaining the maximum SOH value of the battery pack; then, the SOH value of the battery pack disconnected with the bus is subtracted from the maximum SOH value of the battery pack, and the absolute value is obtained to obtain the SOH difference absolute value corresponding to the battery pack disconnected with the bus; and judging whether the absolute value of the SOH difference does not exceed a seventh threshold range, and if the absolute value of the SOH difference does not exceed the seventh threshold range, re-conducting the connection between the corresponding battery pack and the bus.

Through the mode, the battery pack with the battery health state meeting the regulation can be connected with the bus again, and therefore the working efficiency of the battery module can be guaranteed.

In some embodiments, when the battery pack satisfies at least one of the above-described condition (a1), condition (b1), condition (c1), condition (d1), and condition (e1), the corresponding battery pack is disconnected from the bus bar. Then, when an abnormality occurs in a certain battery pack, the battery pack can be disconnected from the bus bar. When the battery module carries out charge and discharge, through above-mentioned mode, can guarantee that the performance parameter of each battery package satisfies certain requirement when the battery module charges and discharges, improve the security and the reliability of battery module at the during operation, simultaneously, reduce the maintenance degree of difficulty to the battery package, improve the convenience of maintaining.

In some embodiments, after the battery pack is disconnected from the bus bar, when the battery pack disconnected from the bus bar satisfies at least one of the above-described condition (a2), condition (b2), condition (c2), condition (d2), and condition (e2), the connection of the corresponding battery pack to the bus bar is restored. Then, when the parameters of a certain battery pack are restored within the specified required range after the battery pack is disconnected from the bus bar, the battery pack can be reconnected to the bus bar. When the battery module charges, through above-mentioned mode, can guarantee that the performance parameter of each battery package satisfies certain requirement when the battery module charges and discharge, improve the security and the reliability of battery module at the during operation, in addition, reduce the maintenance degree of difficulty to the battery package, improve the convenience of maintaining.

It should be noted that the conditions selected for restoring the connection of the battery pack to the bus bar generally correspond to the conditions used to disconnect the battery pack from the bus bar. And when determining whether to recover the connection between the battery pack and the bus, the connection between the battery pack and the bus is recovered when the conditions of the battery pack generally need to meet all the selection conditions.

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 may be set according to empirical values, and are not limited herein.

In some embodiments, the battery module further includes at least one battery management system, the battery management system is respectively 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 comprises at least one of a voltage sampling module, a current sampling module, a temperature sampling module and the like. The voltage sampling module is used for acquiring the voltage, the passive balance electric quantity and the like of each battery pack in real time; 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, the current sampling module and the temperature sampling module transmit the acquired data to the controller, the controller determines the voltage, SOH, SOC and temperature of each battery pack according to the acquired data, and then transmits the voltage, SOH, SOC and temperature of each battery pack to the control unit. It is understood that the voltage sampling module, the current sampling module and the temperature sampling module can be implemented by an existing chip module (e.g., an integrated circuit IC) or a circuit conventional in the art, and the circuit structures of the voltage sampling module, the current sampling module and the temperature sampling module are not described in detail herein.

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 connecting the third switch to disconnect the battery packs in series connection from the bus; or disconnecting the first switch and disconnecting the first end and the third end of the second switch so as to disconnect the battery packs in parallel connection from the bus.

Specifically, when the battery packs in the battery modules are connected in series, as shown in fig. 2, if a certain battery pack in the battery modules satisfies at least one of the conditions (a1), (b1), (c1), (d1) and (e1), the battery pack is disconnected from the bus bar by controlling disconnection between the first end and the second end of the first switch, disconnection between the first end and the second end of the second switch and connection conduction between the first end and the second end of the third switch in the switch unit corresponding to the battery pack, and the other battery packs are still connected in series.

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 disconnection between the first and second ends of the first switch S11, the disconnection between the first and second ends of the second switch S21 and the connection between the first and second ends of the third switch S31 in the first switch unit 21 are controlled, as shown in fig. 7, so that the connection between the first battery pack 11 and the bus bar is disconnected and the other battery packs are still connected in series.

When the battery packs in the battery module are connected in a parallel connection manner, as shown in fig. 3, when the battery packs in the battery module satisfy at least one of the conditions (a1), the condition (b1), the condition (c1), the condition (d1) and the condition (e1), the connection between the battery pack and the bus bar is disconnected by controlling the disconnection between the first terminal and the second terminal of the first switch and the disconnection between the first terminal and the third terminal of the second switch in the switch unit corresponding to the battery pack, but other battery packs are still in a parallel connection manner, so that when a battery pack is cut out from a parallel-connected operating system, the remaining battery packs are still connected in a parallel connection manner, and the system can normally operate.

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 disconnection between the first end and the second end of the first switch S11 and the disconnection between the first end and the second end of the second switch S21 in the first switch unit 21 are controlled, and as shown in fig. 8, 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 parallel.

Therefore, through the mode, when a certain battery pack does not meet the specified requirements, the connection between the certain battery pack and the bus can be disconnected, and other battery packs are still in a normal connection mode, so that the system can still continue to work.

In some embodiments, restoring the connection of the battery pack to the bus bar comprises: the method further includes turning on the first switch, turning on the connection between the first and second terminals of the second switch, and turning off the third switch to restore the connection of the battery packs in the series connection to the bus bar. Or the first switch is conducted, and the connection between the first end and the third end of the second switch is conducted, so that the battery packs in parallel connection are recovered to be connected with the bus.

Specifically, when the battery packs in the battery module are connected in series, when the battery packs in the battery module satisfy at least one of the conditions (a2), (b2), (c2), (d2), and (e2), the connection of the battery pack to the bus bar is made conductive and the battery pack is connected in series with the other battery packs by controlling the connection between the first terminal and the second terminal of the first switch, the connection between the first terminal and the second terminal of the second switch, and the connection between the first terminal and the second terminal of the third switch in the switch unit corresponding to the battery pack to be conductive.

For example, as shown in fig. 7, if the first battery pack 11 satisfies at least one of the conditions (a2), (b2), (c2), (d2) and (e2), the connection between the first and second ends of the first switch S11, the connection between the first and second ends of the second switch S21 and the connection between the first and second ends of the third switch S31 in the first switch unit 21 are controlled to be conductive, and the connection between the first battery pack 11 and the bus bar is restored and the first battery pack is connected in series with the other battery packs.

When the battery packs in the battery module are connected in a parallel connection manner, when the battery packs in the battery module satisfy at least one of the conditions (a2), (b2), (c2), (d2) and (e2), the connection between the battery pack and the bus bar is conducted by controlling the connection conduction between the first terminal and the second terminal of the first switch and the connection conduction between the first terminal and the third terminal of the second switch in the switch unit of the corresponding battery pack, and the battery pack is in a parallel connection manner 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), (b2), (c2), (d2) and (e2), the first switch unit 21 is controlled to conduct the connection between the first terminal and the second terminal of the first switch S11 and the connection between the first terminal and the third terminal of the second switch S21, and the first battery pack 11 is restored to be connected to the bus bar and is connected to the other battery packs in parallel as shown in fig. 4.

Therefore, through the mode, when a certain battery pack disconnected with the bus meets the specified requirement, the battery pack is restored to be connected with the bus and is in the specified connection mode with other battery packs, and therefore the system can still continue to work.

In a second aspect, an embodiment of the present invention further provides an energy storage system, please refer to fig. 8, where the energy storage system includes: an inverter unit 200 and the battery module 100 according to any one of the first aspect. Wherein, the contravariant unit is connected with each battery package electricity through the generating line. When the battery module includes the control unit, the control unit responds to the first instruction signal of contravariant unit, and the break-make of control switch unit, first instruction signal include the type of contravariant unit.

Specifically, the inverter unit includes an energy storage inverter, or any other bidirectional AC/DC converter. In the energy storage system, the battery packs can be connected in series or in parallel by controlling the on-off of the switch unit, so that the connection modes between the battery packs can be flexibly switched, and the compatibility and the adaptability of the energy storage system are improved.

When the battery module comprises the control unit, the control unit in the battery module is in communication connection with the inversion unit, when the inversion unit is the high-voltage inversion unit, the first indication signal comprises information that the inversion unit is high-voltage, and after the control unit receives the first indication signal, the control unit controls the on-off of the switch in each switch unit to enable each battery pack to be connected in series. When the inversion unit is a low-voltage inversion unit, the first indication signal comprises information that the inversion unit is low-voltage, and the control unit controls the on-off of the switch in each switch unit after receiving the first indication signal, so that the battery packs are connected in parallel.

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 a second indication signal of the control unit.

Specifically, when the battery module controls the on-off of the switch unit at each time, in order to ensure the safety of the energy storage system, the control unit sends a second indication signal to the control unit before controlling the on-off of the switch at each time, and the inverter unit limits the current of the bus after receiving the second indication signal, for example, the current is limited to 0A, so that the working reliability and the safety of the system are ensured. In addition, after the on-off of the switch unit is executed, the control unit also sends a third indicating signal to the control unit, and the inverter unit recovers the bus current after receiving the third indicating signal. In practical applications, the first current threshold may be other suitable current values, and the first current threshold is not limited in this embodiment.

In some embodiments, the energy storage system further comprises a DCDC unit. Wherein, the inverter unit is connected with the bus through the DCDC unit. In this battery module, through setting up the DCDC unit, can change the direct current voltage size that the contravariant unit exported to the bus, perhaps, change the direct current voltage size that the bus voltage exported to the contravariant unit to guarantee energy storage system's normal work, and can make energy storage system satisfy different application scenarios, improve energy storage system's suitability.

For example, when the battery packs in the energy storage system are connected in series, when the battery packs are disconnected from the bus, the total voltage between the battery packs will decrease, and at this time, in order to ensure the normal operation of the energy storage system, the DCDC unit should be controlled to adjust the operating voltage of the system. Specifically, if the energy storage system is in a charging state at this time, the DCDC unit should reduce the voltage output by the inverter unit to the bus, and if the energy storage system is in a discharging state for a certain number of times, the DCDC unit should increase the voltage output by the bus to the inverter unit, so that the energy storage system can work normally.

It should be noted that the above-described device embodiments are merely illustrative, where the units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; within the context of the present application, where technical features in the above embodiments or in different embodiments can also be combined, the steps can be implemented 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 described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims

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;

alternatively, the first and second electrodes may be,

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;

alternatively, the first and second electrodes may be,

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.