CN116826924A - Battery cell protection device, FPC sampling circuit and battery system - Google Patents

Abstract

The application relates to a battery cell protection device, an FPC sampling circuit and a battery system. The battery cell protection device comprises a first switch circuit arranged in a protection passage, wherein the first switch circuit comprises a first connecting end connected with a previous battery cell, a second connecting end connected with a next battery cell and a first input end, and the first input end responds to the output voltage of the current battery cell to be lower than a preset voltage so that the first connecting end and the second connecting end are switched from a disconnection state to a connection state. Therefore, when the electric quantity of at least one electric core is lower, the output voltage of the electric core with lower electric quantity is lower than a preset voltage, the electric core with lower electric quantity is the current electric core at the moment, the first switch circuit corresponding to the current electric core is switched to the on state from the off state, so that the former electric core is directly connected with the latter electric core in series through the protection passage, the electric core with lower electric quantity is prevented from being continuously discharged, and other electric cores can be continuously discharged.

Description

Battery cell protection device, FPC sampling circuit and battery system

Technical Field

The application relates to the technical field of batteries, in particular to a battery cell protection device, an FPC sampling circuit and a battery system.

Background

With the development of new energy fields, batteries are used more and more frequently. The vehicle battery mostly adopts a high-voltage system, such as a 400v system, a 600v system, a 800v system and the like, and the high-voltage system is realized by adopting a plurality of battery cells in series connection.

Among the plurality of cells connected in series, the uniformity of the capacity of each cell is low, especially the lithium iron phosphate cell. During the discharging process, the battery cells with lower capacity can consume the electric quantity at first. To avoid the service life of the low-capacity cell from being affected by overdischarge, the battery management system determines that the entire battery has been depleted when the low-capacity cell is depleted, but at this time a significant amount of power is still available. That is, the total capacity of the battery depends on the cell with the lowest capacity, resulting in lower capacity utilization of the battery.

Disclosure of Invention

Based on this, it is necessary to provide a battery cell protection device, an FPC sampling circuit and a battery system that improve the above-mentioned drawbacks, aiming at the problem that the battery capacity utilization rate is low because a considerable amount of electricity is still available when the battery management system in the prior art determines that the electricity of the whole battery has been exhausted.

The battery cell protection device is used for a battery cell group, wherein the battery cell group comprises a plurality of battery cells connected in series, and the battery cell group also comprises a protection passage for connecting a previous battery cell and a next battery cell of the current battery cell in series;

the battery cell protection device comprises a first switch circuit arranged in the protection path, wherein the first switch circuit comprises a first connecting end connected with the previous battery cell, a second connecting end connected with the next battery cell and a first input end, and the first input end responds to the fact that the output voltage of the current battery cell is lower than a preset voltage, so that the first connecting end and the second connecting end are switched from a disconnection state to a connection state.

In one embodiment, the first switch circuit is a not gate switch circuit, and the first switch circuit includes a first transistor that controls the first connection terminal to be turned on or off from the second connection terminal.

In one embodiment, the first transistor has an operating current of 40A to 100A.

In one embodiment, the operating current of the first transistor is 80A.

In one embodiment, the first switching circuit further includes a pre-transistor, a base of the pre-transistor is connected to the first input terminal, an emitter of the pre-transistor is grounded, a collector of the pre-transistor is connected to a power supply through a first resistor, a gate of the first transistor is connected between the collector of the pre-transistor and the first resistor, a source of the first transistor is used as the first connection terminal, and a drain of the first transistor is used as the second connection terminal.

In one embodiment, the cell protection device further includes a comparator circuit, the comparator circuit includes a second input end, an output end and a reference end, the second input end of the comparator circuit is connected to the current cell, the reference end of the comparator circuit is connected to a reference power supply, and the output end of the comparator circuit is connected to the first input end.

In one embodiment, the cell protection device further includes a voltage division circuit, and the current cell is connected to the second input terminal of the comparator circuit through the voltage division circuit.

In one embodiment, the voltage dividing circuit includes a second resistor and a third resistor, a first end of the second resistor is connected to the current cell, a second end of the second resistor is connected to a second input end of the comparator circuit, and the second end of the second resistor is further grounded through the third resistor.

In one embodiment, the cell protection device further comprises a jumper path capable of selectively skipping the voltage divider circuit from the comparator circuit, thereby electrically connecting the current cell directly to the base of the pre-transistor.

In one embodiment, the switch comprises a switch having one end connected to the current cell and the other end connected to the base of the pre-transistor, and the switch is connected to a control device.

In one embodiment, the cell protection device further includes a second switching circuit, where the second switching circuit is disposed in a series circuit of the previous cell and the current cell or in a series path of the current cell and the next cell, and the second switching circuit is switched from an on state to an off state in response to an output voltage of the current cell being lower than a preset voltage.

An FPC sampling circuit comprising a cell protection device as described in any of the embodiments above, the cell protection device being integrated on the FPC sampling circuit.

In one embodiment, the cell protection device is integrated on the FPC sampling circuit in the form of a printed circuit.

The battery system comprises a battery cell group and the FPC sampling circuit in any embodiment, wherein the FPC sampling circuit at least comprises a first connection port and a second connection port, the first connection port and the second connection port are respectively electrically connected with positive and negative poles of the current battery cell, and/or the first connection port is electrically connected with a connecting piece for connecting the positive pole of the current battery cell with the negative pole of the previous battery cell, and the second connection port is electrically connected with a connecting piece for connecting the negative pole of the current battery cell with the positive pole of the next battery cell.

According to the battery cell protection device, the FPC sampling circuit and the battery system, in the discharging process of the battery cell group, each first switch circuit is in an off state, so that each battery cell is connected in series and normally discharges. When at least one cell fails, the output voltage of the cell is reduced to be lower than the preset voltage, and at the moment, the first switch circuit corresponding to the current cell is switched to the on state from the off state, so that the former cell is directly connected with the latter cell in series through the protection channel, the failed cell is disconnected, and the problem that the whole cell group cannot normally output due to the damage of the single cell is avoided.

Alternatively, the power of each cell is gradually reduced as the discharge continues. When the electric quantity of at least one electric core is lower (for example, the electric quantity of the electric core is lower than 5%), the output voltage of the electric core with lower electric quantity is lower than a preset voltage, the electric core with lower electric quantity is the current electric core at the moment, the first switch circuit corresponding to the current electric core is switched to the on state from the off state, so that the former electric core is directly connected with the latter electric core in series through a protection passage, the electric core with lower electric quantity (namely, the current electric core) is prevented from being continuously discharged, and other electric cores can be continuously discharged, and the capacity utilization rate of the battery system is greatly improved on the premise of ensuring that the service life of each electric core is not influenced.

Drawings

FIG. 1 is a schematic diagram of a battery cell according to an embodiment of the application;

fig. 2 is a circuit configuration diagram of a cell protection device according to an embodiment of the present application.

Detailed Description

In order that the above objects, features and advantages of the application will be readily understood, a more particular description of the application will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. The present application may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the application, whereby the application is not limited to the specific embodiments disclosed below.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Referring to fig. 1 and 2, an embodiment of the application provides a battery system including a battery cell group and an FPC (Flexible Printed Circuit, flexible circuit board) sampling circuit. The battery cell group comprises a plurality of battery cells connected in series. Any of the plurality of cells may be used as the current cell 12, and the cell group further includes a protection path 19 connecting the previous cell 12a and the next cell 12b of the current cell 12 in series.

The FPC sampling circuit comprises a cell protection device which is integrated on the FPC sampling circuit in the form of a printed circuit. The cell protection device is disposed in the protection path 19 to control the opening or closing of the protection path 19. When the current cell 12 is normally discharged, the output voltage of the current cell 12 is higher than or equal to a preset voltage, and at this time, the cell protection device controls the protection path 19 to be disconnected, so that the current cell 12 is sequentially connected in series with the previous cell 12a and the next cell 12b, thereby ensuring that the current cell 12 can continue to normally discharge. When the electric quantity of the current cell 12 is low, the output voltage of the current cell 12 is smaller than the preset voltage, and at this time, the cell protection device controls the protection channel 19 to be conducted, so that the previous cell 12a and the next cell 12b are directly connected in series through the protection channel 19, i.e. the current cell 12 is disconnected from the discharge loop of the cell group, and the current cell 12 stops discharging.

It should be noted that, the electric core group includes n electric cores of establishing ties, and every electric core can all be as current electric core 12, and the electric core group includes n protection passageway 19 with n electric cores one-to-one, and every protection passageway 19 all is connected with electric core protection device, and every electric core protection device is used for controlling the switch-on or the disconnection of the protection passageway 19 that is connected with it to realize stopping discharging when the output voltage of arbitrary electric core is less than the preset voltage, realize protecting each electric core promptly, avoid overdischarging and influence life. Wherein n is a positive integer greater than 1, i is a positive integer and 1 < i < n.

With continued reference to fig. 1 and 2, the cell protection device includes a first switching circuit S disposed in the protection path 19. The first switch circuit S includes a first connection terminal S1 connected to the previous cell 12a, a second connection terminal S2 connected to the next cell 12b, and a first input terminal S3. The first input terminal S3 of the first switch circuit S switches the first connection terminal S1 and the second connection terminal S2 of the first switch circuit S from the off state to the on state in response to the output voltage of the current battery cell 12 being lower than the preset voltage.

It should be noted that, the output voltage of the battery cell changes along with the decrease of the electric quantity in the discharging process, for example, when the electric quantity decreases from 95% to 5%, the change curve of the output voltage of the battery cell is a straight line, that is, the output voltage of the battery cell is relatively stable, which is about 3.2V. When the electric quantity is lower than 5%, the output voltage of the battery cell is sharply reduced. Based on the above, a preset voltage can be selected, and when the output voltage of the battery cell is higher than or equal to the preset voltage, the electric quantity of the battery cell is indicated to be between 95% and 5%, so that the discharge can be normally performed. When the output voltage of the battery core is lower than the preset value, the electric quantity of the battery core is indicated to be below 5%, and the discharge needs to be stopped, otherwise, the service life of the battery core is seriously influenced.

According to the battery cell protection device, in the discharging process of the battery cell group, each first switch circuit S is in the off state, so that each battery cell is connected in series and normally discharges, and the electric quantity of each battery cell gradually decreases along with the continuous discharging. When the electric quantity of at least one cell is low (for example, the electric quantity of the cell is lower than 5%), the output voltage of the cell with low electric quantity is lower than a preset voltage, at this time, the cell with low electric quantity is the current cell 12, and the first switch circuit S corresponding to the current cell 12 is switched from the off state to the on state, so that the former cell 12a is directly connected with the latter cell 12b in series through the protection path 19, the cell with low electric quantity (namely, the current cell 12) is prevented from continuously discharging, and other cells can continuously discharging, so that the capacity utilization rate of the battery system is greatly improved on the premise of ensuring that the service lives of the cells are not influenced.

It should be noted that, in the discharging process, when any one of the battery cells in the battery cell group fails, the output voltage of the failed battery cell is reduced to be smaller than the preset voltage, at this time, the failed battery cell is the current battery cell 12, and the first switch circuit S corresponding to the current battery cell 12 is switched from the off state to the on state, so that the previous battery cell 12a is directly connected in series with the next battery cell 12b through the protection path 19, the failed battery cell (i.e., the current battery cell 12) is prevented from continuing in the discharging circuit, and other battery cells can continue to discharge, so that the battery cell group can still discharge normally, and the whole battery pack cannot discharge normally due to the failure of part of the battery cells is prevented.

In the embodiment of the present application, the first switch circuit S is a not gate switch circuit. The first switch circuit S includes a first transistor 20 that controls the first connection terminal S1 to be turned on or off from the second connection terminal S2. In this way, when the output voltage of the current cell 12 is higher than or equal to the preset voltage, the first transistor 20 controls the first connection terminal S1 to be disconnected from the second connection terminal S2, so that the current cell 12 can be normally discharged. When the output voltage of the current cell 12 is lower than the preset voltage, the first transistor 20 controls the first connection terminal S1 and the second connection terminal S2 to be turned on, so that the current cell 12 stops discharging, and other cells can normally discharge. Preferably, the operating current of the first transistor 20 is 40A to 100A. The first transistor 20 may be a MOSFET transistor.

Specifically, the working current of the first transistor 20 is preferably set to 80A, so that the powers corresponding to 400v platform, 600v platform and 800v platform are respectively 32kw,48kw and 64kw, and the reserved powers can enable the vehicle to meet the highest polar speed of about 80km/h and meet the emergency requirement under the expressway working condition. In addition, the MOSFET capable of meeting the above working current has lower cost, and is beneficial to reducing the overall cost.

In some embodiments, the first switching circuit S further comprises a pre-transistor 30. The base of the pre-transistor 30 is connected to the first input terminal S3, the emitter of the pre-transistor 30 is grounded, and the collector of the pre-transistor 30 is connected to a power supply via a first resistor R1. The gate of the first transistor 20 is connected between the collector of the front-end transistor 30 and the first resistor R1, the source of the first transistor 20 serves as the first connection terminal S1, and the drain of the first transistor 20 serves as the second connection terminal S2.

Thus, when the output voltage of the front cell 12 is higher than or equal to the preset voltage, the electric signal introduced into the base electrode of the front transistor 30 from the first input terminal S3 is at a high level, so that the collector electrode and the emitter electrode of the front transistor 30 are turned on, i.e. the power supply is directly grounded, and further the electric signal introduced into the gate electrode of the first transistor 20 is at a low level, so as to ensure that the source electrode and the drain electrode of the first transistor 20 are disconnected, i.e. the first connection terminal S1 is disconnected from the second connection terminal S2, and the protection path 19 connecting the front cell 12a and the rear cell 12b is disconnected at this time, so that the front cell 12 can be discharged normally.

When the output voltage of the front cell 12 is lower than the preset voltage, the electric signal introduced into the base electrode of the front transistor 30 from the first input terminal S3 is at a low level, so that the collector electrode and the emitter electrode of the front transistor 30 are disconnected, and the electric signal introduced into the gate electrode of the first transistor 20 from the power source is at a high level, so as to ensure that the source electrode and the drain electrode of the first transistor 20 are conducted, i.e. the first connection terminal S1 and the second connection terminal S2 are conducted, at this time, the protection path 19 connecting the front cell 12a and the rear cell 12b is conducted, the current cell 12 stops discharging, and other cells can normally discharge.

Thus, the pre-transistor 30 and its associated circuitry can achieve the effect of a not gate switch, i.e., a low level can be output in reverse when a high level is input, and a high level can be output in reverse when a low level is input.

In particular to the embodiment, the cell protection device further includes a comparator circuit M, where the comparator circuit M includes a second input terminal M1, an output terminal M2, and a reference terminal M3. The second input terminal M1 of the comparator circuit M is connected to the current cell 12, the reference terminal M3 of the comparator circuit M is connected to the reference power supply, and the output terminal M2 of the comparator circuit M is connected to the first input terminal S3. In this way, the comparator circuit M compares the voltage introduced to the second input terminal M1 with the voltage introduced to the reference terminal M3 by the reference power supply. When the voltage introduced into the second input terminal M1 is greater than or equal to the voltage introduced into the reference terminal M3, it indicates that the output voltage of the current cell 12 is greater than or equal to the preset voltage, and at this time, the comparator circuit M sends a high level to the first input terminal S3 through the output terminal M2, so that the first connection terminal S1 is disconnected from the second connection terminal S2, and the protection path 19 connecting the previous cell 12a and the next cell 12b is disconnected, so that the current cell 12 can be normally discharged. When the voltage introduced into the second input terminal M1 is smaller than the voltage introduced into the reference terminal M3, it indicates that the output voltage of the current cell 12 is smaller than the preset voltage, and at this time, the comparator circuit M sends a low level to the first input terminal S3 through the output terminal M2, so that the first connection terminal S1 is conducted with the second connection terminal S2, and at this time, the protection path 19 connecting the previous cell 12a and the next cell 12b is conducted, and the current cell 12 stops discharging, while the other cells can normally discharge.

Further, the cell protection device further includes a voltage dividing circuit N, and the current cell 12 is connected to the second input terminal M1 of the comparator circuit M through the voltage dividing circuit N. In this way, the output voltage of the current battery cell 12 is introduced into the second input terminal M1 of the comparator circuit M after being reduced proportionally by the voltage dividing circuit N, so as to ensure that the voltage introduced into the second input terminal M1 of the comparator circuit M is within the operating voltage range of the comparator circuit M, and avoid burning the comparator circuit M due to the voltage introduced into the comparator circuit M exceeding the operating voltage range thereof. Optionally, the voltage dividing circuit N includes a second resistor R2 and a third resistor R3. The first end of the second resistor R2 is connected with the current battery core 12, the second end of the second resistor R2 is connected with the second input end M1 of the comparator circuit M, and the second end of the second resistor R2 is grounded through the third resistor R3, so that voltage division is realized by the aid of the second resistor R2 and the third resistor R3.

Therefore, the comparator circuit M and the voltage dividing circuit N can be used for controlling and adjusting the preset voltage, so that the battery cell protection device can execute switching action when the preset voltage falls into the voltage variation range.

It should be noted that the comparator circuit M is preferably configured to be controllably jumped, specifically, the user may actively choose to skip or not skip the comparator circuit M, when the comparator circuit M is jumped, the operation of jumping off the current cell 12 is performed only if the current cell 12 fails, and when the comparator circuit M is not jumped, the operation of jumping off the current cell 12 is performed when the power consumption of the current cell 12 reaches the predetermined range. The frequency of the battery cell entering the deep discharge cycle can be reduced by adopting the operation, and the service life of the battery cell is prolonged. In addition, the customer can also select to access the comparator circuit M to realize the effect of endurance increase when the customer needs.

In this embodiment, the jump is performed by a jump path (not shown). The trip circuit comprises a trip switch with one end connected with the current battery core and the other end connected with the base electrode of the front-end transistor 30, the trip switch is connected with a control device, and a user can manually control the disconnection and connection of the trip switch through the control device. When the jumper switch is connected, the jumper connection path can skip the voltage dividing circuit N and the comparator circuit M, so that the current battery core is directly and electrically connected with the base electrode of the front-end transistor 30, at the moment, the first switch circuit S can start to skip the fault battery core only when the battery core is in fault, and at the moment, the first switch circuit S only plays a role of insurance.

When the jumper switch is turned off, the current battery cell is connected with the first switch circuit S through the voltage dividing circuit N and the comparator circuit M, and the current battery cell 12 can be jumped when the output voltage is lower than the preset voltage, and the first switch circuit S also has the effect of prolonging the service time of the current battery cell.

It should be noted that, when the first switch circuit S is in the on state, since the first switch circuit S has a certain resistance (2 milliohms to 4 milliohms) and the current battery cell 12 has an internal resistance, the current battery cell 12 still has a certain degree of discharge, so that the electric quantity is further consumed, and there is a risk that the service life of the current battery cell 12 is affected. To overcome this drawback, in some embodiments, the cell protection device further comprises a second switching circuit K disposed in the serial circuit of the previous cell 12a and the current cell 12 or in the serial path of the current cell 12 and the subsequent cell 12 b. The second switch circuit K switches from the on state to the off state in response to the output voltage of the current cell 12 being lower than the preset voltage, so that the current cell 12 is disconnected from the previous cell 12a or the next cell 12b, and the current cell 12 is ensured to be completely disconnected from the discharge loop of the cell group.

In this way, in the discharging process of the battery cell group, when the output voltage of the current battery cell 12 is lower than the preset voltage due to lower electric quantity, the first connection end S1 and the second connection end S2 of the first switch circuit S are turned on, so that the previous battery cell 12a and the next battery cell 12b are directly connected in series; meanwhile, the second switch circuit K is switched from the on state to the off state, so that the current cell 12 is completely disconnected from the previous cell 12a or the next cell 12b, thereby ensuring that the current cell 12 stops discharging, and other cells can continue to normally discharge.

Further, the positive electrode of the current cell 12 is connected to the negative electrode of the previous cell 12a through the first connecting piece 14, and the negative electrode of the current cell 12 is connected to the positive electrode of the next cell 12b through the second connecting piece 16, so that the previous cell 12a, the current cell 12 and the next cell 12b are sequentially connected in series.

The first connection end S1 of the first switch circuit S is connected to the first connection piece 14, and the second connection end S2 of the first switch circuit S is connected to the second connection piece 16, so that when the first connection end S1 and the second connection end S2 of the first switch circuit S are conducted, the protection path 19 between the previous cell 12a and the next cell 12b is conducted; when the first connection terminal S1 and the second connection terminal S2 of the first switch circuit S are disconnected, the protection path 19 between the previous cell 12a and the next cell 12b is disconnected.

The second switch circuit K is disposed between the first connection piece 14 and the positive electrode of the current battery cell 12, and is switched between the on state and the off state before the on state, so as to realize the on or off between the first connection piece 14 and the positive electrode of the current battery cell 12. Or, the second switch circuit K is disposed between the second connection piece 16 and the negative electrode of the current battery cell 12, and is switched between the on state and the off state before the second switch circuit K, so as to implement the on or off between the second connection piece 16 and the negative electrode of the current battery cell 12.

In particular, in the embodiment, the second switch circuit K has a third connection terminal K1, a fourth connection terminal K2, and a third input terminal K3. The third connecting end K1 is connected with the first connecting piece 14, and the fourth connecting end K2 is connected with the positive pole of the current battery cell 12; alternatively, the third connection terminal K1 is connected to the second connection piece 16, and the fourth connection terminal K2 is connected to the negative electrode terminal of the current cell 12. The third input K3 is connected to the output M2 of the comparator circuit M. The third input terminal K3 of the second switch circuit K is responsive to the output voltage of the current battery cell 12 being less than the preset voltage, so that the third connection terminal K1 of the second switch circuit K is disconnected from the fourth connection terminal K2.

In this way, in the discharging process of the battery cell group, when the output voltage of the current battery cell 12 is greater than or equal to the preset voltage, the first connection end S1 and the second connection end S2 of the first switch circuit S are disconnected, and meanwhile, the third connection end K1 and the fourth connection end K2 of the second switch circuit K are conducted, so that the current battery cell 12 is connected in the discharging circuit of the battery cell group and discharges normally. When the output voltage of the current battery cell 12 is smaller than the preset voltage, the first connection end S1 and the second connection end S2 of the first switch circuit S are connected, and meanwhile, the third connection end K1 and the fourth connection end K2 of the second switch circuit K are disconnected, so that the current battery cell 12 and the discharge loop of the battery cell group are disconnected to stop discharging, other battery cells are connected in series and can be normally discharged, and further the service life of the current battery cell 12 is not influenced.

Further, the second switching circuit K includes a second transistor 40. The gate of the second transistor 40 is connected to the output terminal M2 of the comparator circuit M, the source of the second transistor 40 serves as the third connection terminal K1, and the drain of the second transistor 40 serves as the fourth connection terminal K2. Alternatively, the second transistor 40 may be a MOSFET transistor.

In this way, in the discharging process of the battery cell group, when the output voltage of the current battery cell 12 is greater than or equal to the preset voltage, the electric signal output by the output terminal M2 of the comparator circuit M is at a high level, and the electric signal introduced to the gate of the first transistor 20 is at a low level after being introduced to the base of the front-end transistor 30, so that the source and the drain of the first transistor 20 are disconnected, that is, the first connection terminal S1 and the second connection terminal S2 of the first switch circuit S are disconnected; the electrical signal introduced to the gate of the second transistor 40 is at a high level, so that the source and the drain of the second transistor 40 are turned on, i.e. the third connection terminal K1 and the fourth connection terminal K2 of the second switch circuit K are turned on. At this time, the current cell 12 is normally discharged by the first switching circuit S and the second switching circuit K.

When the output voltage of the front cell 12 is lower than the preset voltage, the electric signal output by the output terminal M2 of the comparator circuit M is at a low level, and the low level is introduced into the base of the front-end transistor 30 to make the electric signal introduced into the gate of the first transistor 20 at a high level, so that the source and the drain of the first transistor 20 are turned on, i.e. the first connection terminal S1 and the second connection terminal S2 of the first switch circuit S are turned on; at the same time, the electrical signal introduced to the gate of the second transistor 40 is at a low level, so that the source and the drain of the second transistor 40 are disconnected, i.e. the third connection terminal K1 and the fourth connection terminal K2 of the second switching circuit K are disconnected. At this time, under the action of the first switch circuit S and the second switch circuit K, the current cell 12 is disconnected from the discharge circuit of the cell group, and the discharge is stopped.

In some embodiments, the BATTERY system further includes a BMS (BATTERY MANAGEMENT SYSTEM) connected to the second input terminal M1 of the comparator circuit M. The BMS is configured to introduce a start voltage to the second input terminal M1 of the comparator circuit M when the battery cell pack is charged. The starting voltage is greater than or equal to the voltage introduced to the reference terminal M3 of the comparator circuit M, so that the electric signal output by the output terminal M2 of the comparator circuit M is at a high level, and further the first connection terminal S1 and the second connection terminal S2 of the first switch circuit S are disconnected, and the third connection terminal K1 and the fourth connection terminal K2 of the second switch circuit K are conducted, so that the current battery cell 12 is ensured to be connected into the charging circuit of the battery cell group for charging.

Of course, in order to ensure that each cell in the cell group can be charged during the charging process, the method of controlling the first switch circuit S to be turned off and the second switch circuit K to be turned on by the BMS is not limited. In other embodiments, the cell protection device further comprises a voltage introduction circuit 50, the voltage introduction circuit 50 being connected between the charger and the second input terminal M1 of the comparator circuit M. When the charger is turned on and charges the battery cell group, the voltage introducing circuit 50 introduces a start voltage to the second input terminal M1 of the comparator circuit M. The starting voltage is greater than or equal to the voltage introduced to the reference terminal M3 of the comparator circuit M, so that the electric signal output by the output terminal M2 of the comparator circuit M is at a high level, and further the first connection terminal S1 and the second connection terminal S2 of the first switch circuit S are disconnected, and the third connection terminal K1 and the fourth connection terminal K2 of the second switch circuit K are conducted, so that the current battery cell 12 is ensured to be connected into the charging circuit of the battery cell group for charging. The voltage introduction circuit 50 may be a voltage dividing circuit or the like, as long as an appropriate voltage can be introduced into the second input terminal M1 of the comparator circuit M, and is not limited thereto.

Based on the battery system, the application further provides electric equipment. The electric equipment comprises the battery system in any embodiment, and can be provided with electric energy by the battery system. The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools, energy storage equipment, recreation equipment, elevators, lifting equipment and the like. The vehicle can be a fuel oil vehicle, a fuel gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle; spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, or an electric plane toy, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, electric planers, and the like; the energy storage device can be an energy storage wall, a base station energy storage, a container energy storage and the like; the amusement device may be a carousel, a stair jump machine, or the like. For pure electric vehicles, the battery system can be used as a driving power supply, so that the driving power can be provided by replacing fossil fuel.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims (10)

1. A cell protection device for a cell group, the cell group comprising a plurality of cells connected in series, characterized in that the cell group further comprises a protection path (19) connecting a previous cell (12 a) and a next cell (12 b) of a current cell (12) in series; the battery cell protection device comprises a first switch circuit (S) arranged in a protection passage (19), wherein the first switch circuit (S) comprises a first connecting end (S1) connected with a previous battery cell (12 a), a second connecting end (S2) connected with a next battery cell (12 b) and a first input end (S3), and the first input end (S3) responds to the fact that the output voltage of the current battery cell (12) is lower than a preset voltage, so that the first connecting end (S1) and the second connecting end (S2) are switched from a disconnection state to a connection state.

2. The cell protection device according to claim 1, wherein the first switching circuit (S) is a not gate switching circuit, the first switching circuit (S) comprising a first transistor (20) controlling the connection or disconnection of the first connection terminal (S1) and the second connection terminal (S2); and/or

The operating current of the first transistor (20) is 40A to 100A; and/or

The operating current of the first transistor (20) is 80A.

3. The cell protection device according to claim 2, wherein the first switching circuit (S) further comprises a pre-transistor (30), a base of the pre-transistor (30) is connected to the first input terminal (S3), an emitter of the pre-transistor (30) is grounded, a collector of the pre-transistor (30) is connected to a power supply via a first resistor (R1), a gate of the first transistor (20) is connected between the collector of the pre-transistor (30) and the first resistor (R1), a source of the first transistor (20) serves as the first connection terminal (S1), and a drain of the first transistor (20) serves as the second connection terminal (S2).

4. A cell protection device according to claim 3, characterized in that the cell protection device further comprises a comparator circuit (M), the comparator circuit (M) comprising a second input (M1), an output (M2) and a reference (M3), the second input (M1) of the comparator circuit (M) being connected to the current cell (12), the reference (M3) of the comparator circuit (M) being connected to a reference power supply, the output (M2) of the comparator circuit (M) being connected to the first input (S3); and/or

The battery cell protection device further comprises a voltage division circuit (N), and the current battery cell (12) is connected with a second input end (M1) of the comparator circuit (M) through the voltage division circuit (N); and/or

The voltage dividing circuit (N) comprises a second resistor (R2) and a third resistor (R3), a first end of the second resistor (R2) is connected with the current battery cell (12), a second end of the second resistor (R2) is connected with a second input end (M1) of the comparator circuit (M), and a second end of the second resistor (R2) is grounded through the third resistor (R3).

5. The cell protection device of claim 4, further comprising a jumper path capable of selectively skipping the voltage divider circuit (N) from the comparator circuit (M) such that the current cell (12) is directly electrically connected to the base of the pre-transistor (30).

6. The cell protection device according to claim 5, wherein the trip circuit comprises a trip switch having one end connected to the current cell (12) and the other end connected to the base of the pre-transistor (30), the trip switch being connected to a control device.

7. The cell protection device according to claim 1, further comprising a second switching circuit (K) provided in a series path of the previous cell (12 a) and the current cell (12) or in a series path of the current cell (12) and the subsequent cell (12 b), the second switching circuit (K) being switched from an on state to an off state in response to an output voltage of the current cell (12) being lower than a preset voltage.

8. An FPC sampling circuit comprising a cell protection device according to any one of claims 1 to 7, said cell protection device being integrated on said FPC sampling circuit.

9. The FPC sampling circuit of claim 8, wherein the cell protection device is integrated on the FPC sampling circuit in the form of a printed circuit.

10. A battery system, characterized by comprising a battery cell group and the FPC sampling circuit according to claim 9, wherein the FPC sampling circuit at least comprises a first connection port and a second connection port, the first connection port and the second connection port are respectively electrically connected with positive and negative poles of the current battery cell (12), and/or the first connection port is electrically connected with a connection piece connecting the positive pole of the current battery cell (12) and the negative pole of the previous battery cell (12 a), and the second connection port is electrically connected with a connection piece connecting the negative pole of the current battery cell (12) and the positive pole of the next battery cell (12 b).