CN115133626A

CN115133626A - Battery protection circuit, control method thereof and battery management system

Info

Publication number: CN115133626A
Application number: CN202210948095.4A
Authority: CN
Inventors: 谢耀华
Original assignee: Hubei Eve Power Co Ltd
Current assignee: Hubei Eve Power Co Ltd
Priority date: 2022-08-09
Filing date: 2022-08-09
Publication date: 2022-09-30

Abstract

The embodiment of the invention discloses a battery protection circuit, a control method thereof and a battery management system. The battery protection circuit comprises a switch module, a fusing module and a first detection module; the switch module, the fusing module and the battery pack are connected in series between a first power supply end and a second power supply end; the switch module is arranged close to the second power supply end and used for responding to a signal of the control end of the switch module to be switched on or switched off so as to control charging and discharging of the battery pack; the fusing module is used for responding to the signal disconnection of the control end of the fusing module; the first detection module is used for acquiring signals of the second power supply end and the control end of the switch module, determining the on-state of the switch module according to the signals of the second power supply end, and controlling the fusing module to be disconnected when the signals of the control end of the switch module are off level signals and the switch module is in the on-state. The technical scheme of the embodiment of the invention is beneficial to enhancing the safety and reliability of the battery pack and the battery protection circuit.

Description

Battery protection circuit, control method thereof and battery management system

Technical Field

The embodiment of the invention relates to the technical field of batteries, in particular to a battery protection circuit, a control method thereof and a battery management system.

Background

The conventional Battery Management System (BMS) generally includes a Battery pack and a protection circuit thereof, the protection circuit of the Battery pack includes a fuse device connected in series with the Battery pack, and the protection circuit of the Battery pack can control whether the fuse device is disconnected according to voltage, current parameters and the like of the Battery pack, so as to improve the safety and reliability of the BMS.

However, when the battery management system BMS is subjected to an impact of an external signal, the protection circuit of the battery pack is often abnormal, so that the disconnection of the fuse device cannot be accurately controlled, and a safety accident is easily caused.

Disclosure of Invention

The embodiment of the invention provides a battery protection circuit, a control method thereof and a battery management system, which are used for triggering a fusing module to normally start under the conditions that a battery pack and the battery protection circuit are impacted by external signals and the like, so that the protection effect under an abnormal state is achieved, and the safety and reliability of the battery pack and the battery protection circuit are enhanced.

In a first aspect, an embodiment of the present invention provides a battery protection circuit, including:

the battery pack comprises a switch module and a fusing module, wherein the switch module, the fusing module and the battery pack are connected in series between a first power supply end and a second power supply end; the switch module is arranged close to the second power supply end and is used for responding to the signal of the control end of the switch module to be switched on or switched off so as to control the charging and discharging of the battery pack; the fusing module is used for responding to the signal disconnection of the control end of the fusing module;

the first detection module is connected with the second power end, the control end of the switch module and the control end of the fusing module, and is used for acquiring signals of the second power end and the control end of the switch module, determining the on-state of the switch module according to the signal of the second power end, and controlling the fusing module to be disconnected when the signal of the control end of the switch module is a turn-off level signal and the switch module is in the on-state.

Optionally, the fuse module comprises a first switch and a fuse device;

the control end of the first switch is used as the control end of the fusing module, the first end of the first switch is connected with the control end of the fusing device, the second end of the first switch is grounded, and the fusing device is connected with the switch module and the battery pack in series;

the first switch is used for being switched on or switched off according to a signal of a control end of the first switch so as to control the fusing device to be switched off when the first switch is switched on;

the fuse device includes a three-terminal fuse.

Optionally, the battery protection circuit further includes a control module, connected to the battery pack, the control terminal of the switch module, and the control terminal of the fusing module, and configured to control the switch module and the fusing module;

the switch module comprises a first transistor and a second transistor, the first transistor and the second transistor are connected between the first power supply end and the second power supply end in series, and the grid electrode of the first transistor and/or the second transistor is used as the control end of the switch module.

Optionally, the first detection module includes a first detection unit, a second detection unit, a third detection unit, and an and gate circuit;

the input end of the first detection unit is connected with the control end of the switch module, the output end of the first detection unit is connected with the first input end of the AND gate circuit, and the first detection unit is used for outputting a first level signal when a signal of the control end of the switch module is an off level signal and outputting a second level signal when the signal of the control end of the switch module is an on level signal;

the input end of the second detection unit is connected with the second power end, the output end of the second detection unit is connected with the second input end of the AND-gate circuit, the first electrode of the battery pack is connected with the first power end, the switch module is connected between the second electrode of the battery pack and the second power end, a load is connected between the first power end and the second power end, the second detection unit is used for outputting the first level signal when the signal of the second power end is the second electrode signal of the battery pack, and outputting the second level signal when the signal of the second power end is the first electrode signal of the battery pack;

the input end of the third detection unit is connected between the battery pack and the switch module, the output end of the third detection unit is connected with the third input end of the AND gate circuit, the third detection unit is used for outputting the first level signal when the current between the battery pack and the switch module is greater than or equal to the set current, and outputting the second level signal when the current between the battery pack and the switch module is less than the set current;

the output end of the AND-gate circuit is connected with the control end of the fusing module, and the AND-gate circuit is used for outputting the first level signal to the control end of the fusing module to control the fusing module to be disconnected when the signals of the first input end, the second input end and the third input end of the AND-gate circuit are the first level signals.

Optionally, the first detection unit includes a first diode, a first resistor, and a second switch, an anode of the first diode is connected to the control terminal of the switch module, a cathode of the first diode is connected to the control terminal of the second switch, a first terminal of the second switch is connected to a power supply terminal through the first resistor, and a second terminal of the second switch is grounded;

the second detection unit comprises a second diode, a second resistor and a third switch, wherein the anode of the second diode is connected with the second power supply end, the cathode of the second diode is connected with the control end of the third switch, the first end of the third switch is connected with the power supply end through the second resistor, and the second end of the third switch is grounded;

the third detection unit comprises a first comparator, a third resistor, a fourth resistor and a fifth resistor, wherein a first end of the third resistor is connected with a reference voltage end, a second end of the third resistor is connected with a first end of the fourth resistor, a second end of the fourth resistor is grounded, a first comparison signal input end of the first comparator is connected with a second end of the third resistor, a sixth resistor is connected in series between the battery pack and the switch module, a second comparison signal input end of the first comparator is connected with the sixth resistor, and an output end of the first comparator is connected with a power supply end through the fifth resistor;

the AND circuit comprises a third diode, a fourth diode, a fifth diode and a seventh resistor, wherein the first end of the seventh resistor is connected with a power supply end, the cathode of the third diode is connected with the first end of the second switch, the cathode of the fourth diode is connected with the first end of the third switch, the cathode of the fifth diode is connected with the output end of the first comparator, the anode of the third diode, the anode of the fourth diode and the anode of the fifth diode are connected with the second end of the seventh resistor, and the second end of the seventh resistor is connected with the control end of the fusing module.

Optionally, the battery protection circuit further includes a delay module and a second detection module;

the time delay module is connected between the first detection module and the control end of the fusing module and is used for outputting an output signal of the first detection module to the control end of the fusing module in a time delay manner;

the second detection module is connected with the delay module and is used for detecting the temperature of the switch module and controlling the delay time of the delay module to be shortened when the temperature of the switch module is greater than or equal to a set temperature.

Optionally, the delay module includes an eighth resistor and a first capacitor, the eighth resistor is connected between the first detection module and the control terminal of the fuse module, a first pole of the first capacitor is connected between the eighth resistor and the control terminal of the fuse module, and a second pole of the first capacitor is grounded;

the second detection module comprises a ninth resistor, a tenth resistor, an eleventh resistor, a thermistor, an optocoupler, a second comparator and a fourth switch, wherein the first end of the ninth resistor is connected with a power supply end, the second end of the ninth resistor is connected with the first end of the thermistor, the second end of the thermistor is grounded, the first comparison signal input end of the second comparator is connected with a reference voltage, the second comparison signal input end of the second comparator is connected with the second end of the ninth resistor, the tenth resistor is connected between the output end of the second comparator and the second comparison signal input end, the eleventh resistor is connected between the output end of the second comparator and the power supply end, the output end of the second comparator is connected with the control end of the fourth switch, and the first input end of the optocoupler is connected with the power supply end, the first output end of the optical coupler is connected with the first end of the fourth switch, the second end of the fourth switch is grounded, the second input end of the optical coupler is connected with the first end of the eighth resistor, and the second output end of the optical coupler is connected with the second end of the eighth resistor.

In a second aspect, an embodiment of the present invention provides a method for controlling a battery protection circuit, where the battery protection circuit includes: the device comprises a switch module, a fusing module and a first detection module; the switch module, the fusing module and the battery pack are connected between a first power supply end and a second power supply end; the switch module is arranged close to the second power supply end and is used for responding to the signal of the control end of the switch module to be switched on or switched off so as to control the charging and discharging of the battery pack; the fusing module is used for responding to the signal disconnection of the control end of the fusing module; the first detection module is connected with the second power supply end, the control end of the switch module and the control end of the fusing module;

the control method of the battery protection circuit comprises the following steps:

acquiring signals of the second power supply end and a control end of the switch module through the first detection module;

determining the conducting state of the switch module according to the signal of the second power supply end through the first detection module;

the fuse module is controlled to be disconnected when the signal of the control end of the switch module is an off level signal and the switch module is in a conducting state through the first detection module.

Optionally, the battery protection circuit further includes a delay module and a second detection module; the time delay module is connected between the first detection module and the control end of the fusing module, and the second detection module is connected with the time delay module;

the control method of the battery protection circuit further includes:

the output signal of the first detection module is output to the control end of the fusing module in a delayed mode through the delay module;

and detecting the temperature of the switch module through the second detection module, and controlling the delay time of the delay module to be shortened when the temperature of the switch module is greater than or equal to the set temperature.

In a third aspect, an embodiment of the present invention provides a battery management system, including a battery pack and the battery protection circuit described in the first aspect, or a control method applying the battery protection circuit described in the second aspect.

According to the battery protection circuit, the control method and the battery management system provided by the embodiment of the invention, the first detection module is used for acquiring the signals of the second power supply end and the control end of the switch module, the conducting state of the switch module is determined according to the signal of the second power supply end, and the switch module is determined to be broken and damaged when the signal of the control end of the switch module is an off level signal and the switch module is in the conducting state, so that the first detection module is used for controlling the disconnection of the fusing module, the normal starting of the fusing module is triggered under the conditions that the battery pack and the battery protection circuit are impacted by external signals and the like, the protection effect under the abnormal state is achieved, and the safety and reliability of the battery pack and the battery protection circuit are favorably enhanced.

It should be understood that the statements in this section do not necessarily identify key or critical features of the embodiments of the present invention, nor do they necessarily limit the scope of the invention. Other features of the present invention will become apparent from the following description.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a battery protection circuit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of another battery protection circuit provided in the embodiment of the present invention;

fig. 3 is a schematic structural diagram of a first detection module according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a first detection module, a delay module, and a second detection module according to an embodiment of the present invention;

fig. 5 is a schematic flowchart of a control method of a battery protection circuit according to an embodiment of the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The embodiment of the invention provides a battery protection circuit. Fig. 1 is a schematic structural diagram of a battery protection circuit according to an embodiment of the present invention. Referring to fig. 1, the battery protection circuit includes: a switch module 10, a fuse module 20, and a first detection module 40.

Wherein the switching module 10, the fusing module 20, and the battery pack 30 are connected in series between the first power source terminal V1 and the second power source terminal V2. The switch module 10 is disposed near the second power supply terminal V2, and the switch module 10 is configured to be turned on or off in response to a signal from its control terminal to control charging and discharging of the battery pack 30. The fuse module 20 is configured to open in response to a signal from a control terminal thereof.

The first detecting module 40 is connected to the second power source terminal V2, the control terminal of the switch module 10, and the control terminal of the fuse module 20, and is configured to obtain signals of the second power source terminal V2 and the control terminal of the switch module 10, determine the on state of the switch module 10 according to the signal of the second power source terminal V2, and control the fuse module 20 to be turned off when the signal of the control terminal of the switch module 10 is an off level signal and the switch module 10 is in the on state.

Specifically, the battery pack 30 may be a lithium-ion power battery, for example, the battery pack 30 may be a battery pack in a battery management system BMS. Battery pack 30 is connected in series between first power supply terminal V1 and second power supply terminal V2, a load may be connected between first power supply terminal V1 and second power supply terminal V2 to discharge the load through battery pack 30, and first power supply terminal V1 and second power supply terminal V2 may also be connected to a power supply to charge battery pack 30, respectively. Either one of the switching module 10 and the fuse module 20 may be connected in series between the first power source terminal V1 and the first electrode of the battery pack 30, or between the second power source terminal V2 and the second electrode of the battery pack 30. When the first electrode of the battery pack 30 is a positive electrode and the second electrode of the battery pack 30 is a negative electrode, the first power supply terminal V1 is used as a positive electrode of the power supply, and the second power supply terminal V2 is used as a negative electrode of the power supply; when the first electrode of the battery 30 is a negative electrode and the second electrode of the battery 30 is a positive electrode, the first power supply terminal V1 is a negative electrode and the second power supply terminal V2 is a positive electrode. The switch module 10 is disposed close to the second power supply terminal V2, which means that the switch module 10 is connected in series between the second power supply terminal V2 and the second electrode of the battery pack 30. In each embodiment of the present invention, the case where the fusing module 20 is connected in series between the second power source terminal V2 and the second electrode of the battery pack 30 is taken as an example, in other embodiments, the fusing module 20 may be connected in series between the first power source terminal V1 and the first electrode of the battery pack 30.

By transmitting different signals to the control terminal of the switch module 10, the switch module 10 can be controlled to be turned on or off to control the connection or disconnection between the second electrode of the battery pack 30 and the second power terminal V2, so as to control the charging and discharging of the battery pack 30. The fusing module 20 may be fused when a current flowing through itself is too large, and the fusing module 20 may be controlled to be fused by transmitting a control signal to a control terminal of the fusing module 20, so as to protect the battery pack 30.

Optionally, the battery protection circuit further includes a control module 50, the control module 50 is connected to the battery pack 30, the control terminal of the switch module 10, and the control terminal of the fuse module 20, and the control module 50 may transmit a signal to the control terminal of the switch module 10 to control the switch module 10 to turn on or off, so as to control charging and discharging of the battery pack 30. The control module 50 may also transmit a signal to the control terminal of the fusing module 20 to control the fusing module 20, for example, the control module 50 may obtain a cell voltage of the battery pack 30 during charging, and transmit a signal to the control terminal of the fusing module 20 when the cell voltage of the battery pack 30 exceeds a voltage threshold, so as to trigger the fusing module 20 to fuse, and stop the charging process of the battery pack 30, so as to protect the battery pack 30.

The signal of the control end of the switch module 10 is an on level signal or an off level signal, the on level signal is a signal for controlling the switch module 10 to be turned on, the off level signal is a signal for controlling the switch module 10 to be turned off, and the first detection module 40 can determine that the signal of the control end of the switch module 10 is the on level signal or the off level signal by acquiring the signal of the control end of the switch module 10. The first detecting module 40 can determine the on-state between the battery pack 30 and the second power source terminal V2 by obtaining the signal of the second power source terminal V2, so as to determine the on-state of the switch module 10, for example, in case that the fusing module 20 is not fused, if the first detecting module 40 determines that the battery pack 30 is connected to the second power source terminal V2 according to the signal of the second power source terminal V2, the switch module 10 can be further determined to be in the on-state, and if the first detecting module 40 determines that the battery pack 30 is disconnected from the second power source terminal V2 according to the signal of the second power source terminal V2, the switch module 10 can be further determined to be in the off-state. When the battery pack 30 is charged/discharged, if the first detection module 40 determines that the signal of the control terminal of the switch module 10 is an off level signal and the switch module 10 is in an on state according to the signals of the second power terminal V2 and the control terminal of the switch module 10, it indicates that the switch module 10 is damaged, for example, the battery pack 30 and the battery protection circuit may be impacted by an external signal to cause breakdown of the switch module 10, so that the first detection module 40 may transmit a control signal to the control terminal of the fuse module 20 to control the fuse module 20 to fuse, thereby protecting the battery pack 30.

According to the technical scheme of the embodiment of the invention, the signals of the second power supply end and the control end of the switch module are acquired through the first detection module, the on-state of the switch module is determined according to the signal of the second power supply end, the breakdown damage of the switch module is determined when the signal of the control end of the switch module is a turn-off level signal and the switch module is in the on-state, so that the fuse module is controlled to be switched off through the first detection module, the fuse module is triggered to be normally started under the conditions that the battery pack and the battery protection circuit are impacted by external signals and the like, the protection effect in an abnormal state is achieved, and the safety and reliability of the battery pack and the battery protection circuit are enhanced.

Fig. 2 is a schematic structural diagram of another battery protection circuit according to an embodiment of the present invention. Referring to fig. 2, on the basis of the above embodiment, the fusing module 20 optionally includes a first switch K1 and a fusing device 210. The control terminal of the first switch K1 serves as the control terminal of the fuse module 20, the first terminal of the first switch K1 is connected to the control terminal of the fuse device 210, the second terminal of the first switch K1 is grounded, and the fuse device 210 is connected in series with the switch module 10 and the battery pack 30. The first switch K1 is used to turn on or off according to a signal from its control terminal to control the fuse device 210 to turn off when turned on.

Specifically, the first switch K1 may be a Transistor, such as a triode, a Field Effect Transistor (fet), or the like, the Field Effect Transistor includes a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), or the like, and the first switch K1 may be an N-type Transistor or a P-type Transistor. Illustratively, in the case where the first switch K1 is a metal-oxide semiconductor field effect transistor MOSFET, the gate of the transistor serves as the control terminal, one of the source and the drain serves as the first terminal, and the other serves as the second terminal. The fuse device 210 may be a three-terminal fuse, which is connected in series with the switching module 10 and the battery pack 30, and has a control terminal connected to the first terminal of the first switch K1. The first switch K1 may be controlled to be turned on or off by transmitting a signal to a control terminal of the first switch K1, when the first switch K1 is turned on, the control terminal of the fuse device 210 may be connected to a ground terminal to control the fuse device 210 to be blown, and when the first switch K1 is turned off, the control terminal of the fuse device 210 is not connected to the signal, and the fuse device 210 remains as it is.

Further, the switch module 10 includes a first transistor M1 and a second transistor M2, the first transistor M1 and the second transistor M2 are connected in series between the first power source terminal V1 and the second power source terminal V2, and gates of the first transistor M1 and/or the second transistor M2 are used as control terminals of the switch module 10.

Specifically, the first transistor M1 and the second transistor M2 may be metal-oxide semiconductor field effect transistors MOSFETs, and the first transistor M1 is controlled to be turned on or off to control the discharging process of the battery pack 30, and the second transistor M2 is controlled to be turned on or off to control the charging process of the battery pack 30. In one embodiment, the gate of the first transistor M1 may be used as the control terminal of the switch module 10, that is, the first detecting module 40 may be connected to the gate of the first transistor M1 to determine whether the gate signal of the first transistor M1 is an on-level signal or an off-level signal, so that the on-state of the first transistor M1 is determined by the first detecting module 40 according to the signal of the second power source terminal V2 to control the blowing module 20 to be turned off when the gate signal of the first transistor M1 is an off-level signal and the first transistor M1 is in the on-state. In another embodiment, the gate of the second transistor M2 may be used as the control terminal of the switch module 10, that is, the first detecting module 40 may be connected to the gate of the second transistor M2 to determine whether the gate signal of the second transistor M2 is an on-level signal or an off-level signal, so as to determine the on-state of the second transistor M2 according to the signal of the second power source terminal V2 through the first detecting module 40, and to control the blowing module 20 to be turned off when the gate signal of the second transistor M2 is an off-level signal and the second transistor M2 is in the on-state. In another embodiment, the gate of the first transistor M1 and the gate of the second transistor M2 may both serve as the control terminals of the switch module 10, that is, the first detection module 40 may be connected to the gate of the first transistor M1 and the gate of the second transistor M2, respectively, to determine the gate signals of the first transistor M1 and the second transistor M2, so as to determine the on-states of the first transistor M1 and the second transistor M2 according to the signal of the second power terminal V2 through the first detection module 40, so as to control the fuse module 20 to be disconnected when the gate signal of the first transistor M1 is an off-level signal and the first transistor M1 is in an on-state, and control the fuse module 20 to be disconnected when the gate signal of the second transistor M2 is an off-level signal and the second transistor M2 is in an on-state.

With continued reference to fig. 2, further, the control module 50 includes a control unit 510, a parameter acquisition unit 520, and a drive unit 530. The parameter collecting unit 520 is connected to the battery pack 30, the control unit 510 is respectively connected to the parameter collecting unit 520, the driving unit 530 and the control terminal of the fusing module 20, and the driving unit 530 is connected to the control terminal of the switch module 10. The parameter collecting unit 520 may be a secondary protection chip, and the parameter collecting unit 520 is configured to obtain parameters of the battery pack 30, for example, the parameter collecting unit 520 may obtain parameters of a cell voltage, a temperature, a current, and the like in the battery pack 30. The driving unit 530 is used for driving the switch module 10, and in a case that the switch module 10 includes the first transistor M1 and the second transistor M2, the driving unit 530 may connect the gate of the first transistor M1 and the gate of the second transistor M2 to drive the first transistor M1 and the second transistor M2, and control the first transistor M1 and the second transistor M2 to be turned on and off. The control unit 510 may be a central processing unit (MCU), the control unit 510 may control the driving unit 530 to drive the switch module 10 according to the parameters collected by the parameter collecting unit 520, and control the fusing module 20 according to the parameters collected by the parameter collecting unit 520, for example, the parameter collecting unit 520 may transmit the cell voltage of the battery pack 30 to the control unit 510, and the control unit 510 may transmit a signal to a control terminal of the fusing module 20 when the cell voltage of the battery pack 30 exceeds a voltage threshold, so as to trigger the fusing module 20 to fuse. In other embodiments, the cell voltage of the Analog Front End (AFE), the gate voltages of the first transistor M1 and the second transistor M2, and the currents of the first transistor M1 and the second transistor M2 may also be collected by the control unit 510 to control the fuse module 20 according to the above parameters.

Fig. 3 is a schematic structural diagram of a first detection module according to an embodiment of the present invention, and fig. 3 illustrates a connection relationship among the first detection module 40, the fuse module 20, and the control module 50. With reference to fig. 2 and 3, optionally, the first detection module 40 includes a first detection unit 410, a second detection unit 420, a third detection unit 430, and an and circuit 440.

The input end of the first detecting unit 410 is connected to the control end of the switch module 10, the output end of the first detecting unit 410 is connected to the first input end of the and circuit 440, and the first detecting unit 410 is configured to output a first level signal when a signal at the control end of the switch module 10 is an off level signal, and output a second level signal when a signal at the control end of the switch module 10 is an on level signal.

The input terminal of the second detection unit 420 is connected to the second power source terminal V2, the output terminal of the second detection unit 420 is connected to the second input terminal of the and circuit 440, the first electrode of the battery pack 30 is connected to the first power source terminal V1, the switch module 10 is connected between the second electrode of the battery pack 30 and the second power source terminal V2, a load is connected between the first power source terminal V1 and the second power source terminal V2, the second detection unit 420 is configured to output a first level signal when the signal of the second power source terminal V2 is the second electrode signal of the battery pack 30, and output a second level signal when the signal of the second power source terminal V2 is the first electrode signal of the battery pack 30.

The input terminal of the third detection unit 430 is connected between the battery pack 30 and the switch module 10, the output terminal of the third detection unit 430 is connected to the third input terminal of the and circuit 440, and the third detection unit 430 is configured to output a first level signal when the current between the battery pack 30 and the switch module 10 is greater than or equal to the set current, and output a second level signal when the current between the battery pack 30 and the switch module 10 is less than the set current.

The output end of the and circuit 440 is connected to the control end of the fuse module 20, and the and circuit 440 is configured to output a first level signal to the control end of the fuse module 20 to control the fuse module 20 to be disconnected when the signals of the first input end, the second input end, and the third input end of the and circuit are all first level signals.

Illustratively, one of the on-level signal and the off-level signal of the control terminal of the switch module 10 is a high-level signal, and the other is a low-level signal. One of the first level signal and the second level signal is a high level signal, and the other is a low level signal. In this embodiment, the gate of the first transistor M1 may be provided as the control terminal of the switch module 10, the input terminal of the first detection module 40 is connected to the gate of the first transistor M1, and is connected to the gate voltage signal Vg of the first transistor M1, so as to output a first level signal when the gate voltage signal Vg of the first transistor M1 is an off level signal, and output a second level signal when the gate voltage signal Vg of the first transistor M1 is an on level signal.

When the first electrode of the battery 30 is a positive electrode and the second electrode of the battery 30 is a negative electrode, the first power source terminal V1 is a positive electrode and the second power source terminal V2 is a negative electrode. A load is connected between the first power source terminal V1 and the second power source terminal V2, and when the gate voltage signals of the first transistor M1 and the second transistor M2 are off-level signals, the normal states of the first transistor M1 and the second transistor M2 are both off-states. If both the first transistor M1 and the second transistor M2 are in the normal state, the signal of the second power terminal V2 is pulled up to the signal of the first power terminal V1, i.e., the first electrode signal (positive electrode signal) of the battery pack 30, and the second detecting unit 420 can output a second level signal to determine that the first transistor M1 is in the off state. In the case where the first transistor M1 and the second transistor M2 are broken down, the signal of the second power source terminal V2 is a second electrode signal (a negative electrode signal, e.g., a ground signal) of the battery pack 30, and the second detection unit 420 may output a first level signal to determine that the first transistor M1 is in a turn-on state.

The input terminal of the third detecting unit 430 is connected between the battery pack 30 and the switch module 10, and is connected to the current signal VRs, the third detecting unit 430 may determine whether a current flows through the first transistor M1 by comparing the current signal VRs with a set current, so as to further determine the conducting state of the first transistor M1, for example, the set current may be a minimum operating current of the first transistor M1, when the current signal VRs is greater than or equal to the set current, it may be determined that the first transistor M1 is in the conducting state, and the third detecting unit 430 may output a first level signal. When the current signal VRs is less than the set current, it may be determined that the first transistor M1 is in an off state, and the third detection unit 430 may output a second level signal.

When the gate signal Vg of the first transistor M1 is an off level signal and the first transistor M1 is broken down, the first detection unit 410, the second detection unit 420 and the third detection unit 430 all output a first level signal, and the and circuit 440 may output the first level signal according to signals of its first input terminal, second input terminal and third input terminal, so as to control the first switch K1 to be turned on through the first level signal, further control the fuse device 210 to fuse, and protect the battery pack 30.

It should be noted that, in the above embodiment, only the gate of the first transistor M1 is taken as the control terminal of the switch module 10, and the first detection module 40 controls the fuse device 210 according to the state of the first transistor M1 is taken as an example for description, in other embodiments, the gate of the second transistor M2 may be taken as the control terminal of the switch module 10, and the first detection module 40 may also control the fuse device 210 according to the state of the second transistor M2, which is not limited in this embodiment.

Fig. 4 is a schematic structural diagram of a first detection module, a delay module, and a second detection module according to an embodiment of the present invention, and fig. 4 illustrates a connection relationship among the fuse module 20, the first detection module 40, the control module 50, the delay module 60, and the second detection module 70. With reference to fig. 2 and 4, further, the first detecting unit 410 includes a first diode D1, a first resistor R1, and a second switch K2, an anode of the first diode D1 is connected to the control terminal of the switch module 10, a cathode of the first diode D1 is connected to the control terminal of the second switch K2, a first terminal of the second switch K2 is connected to the power source terminal VCC through the first resistor R1, and a second terminal of the second switch K2 is grounded. The first diode D1 is used to prevent the signal from flowing backward, the first resistor R1 is used to divide the voltage, the second switch K2 may be a transistor, such as a triode or a field effect transistor, in this embodiment, the second switch K2 may be set to be a triode, the base of the triode may be used as the control terminal of the second switch K2, one of the collector and the emitter of the triode may be used as the first terminal of the second switch K2, and the other one is used as the second terminal of the second switch K2.

The second detecting unit 420 includes a second diode D2, a second resistor R2, and a third switch K3, wherein an anode of the second diode D2 is connected to a second power terminal V2, a cathode of the second diode D2 is connected to a control terminal of the third switch K3, a first terminal of the third switch K3 is connected to a power terminal VCC through the second resistor R2, and a second terminal of the third switch K3 is grounded. The second diode D2 is used to prevent the signal from flowing backward, the second resistor R2 is used to divide the voltage, the third switch K3 may be a transistor, such as a triode or a field effect transistor, in this embodiment, the third switch K3 may be set to be a triode, a base of the triode may serve as a control terminal of the third switch K3, one of a collector and an emitter of the triode may serve as a first terminal of the third switch K3, and the other one serves as a second terminal of the third switch K3.

The third detecting unit 430 includes a first comparator F1, a third resistor R3, a fourth resistor R4 and a fifth resistor R5, a first end of the third resistor R3 is connected to the reference voltage terminal to access the reference voltage Vref, a second end of the third resistor R3 is connected to a first end of the fourth resistor R4, a second end of the fourth resistor R4 is grounded, a first comparison signal input terminal of the first comparator F1 is connected to a second end of the third resistor R3, a sixth resistor R6 is connected in series between the battery pack 30 and the switch module 10, a second comparison signal input terminal of the first comparator F1 is connected to the sixth resistor R6, and an output terminal of the first comparator F1 is connected to the power supply terminal VCC through the fifth resistor R5. The third resistor R3, the fourth resistor R4 and the fifth resistor R5 are all used for voltage division.

The and circuit 440 includes a third diode D3, a fourth diode D4, a fifth diode D5 and a seventh resistor R7, a first end of the seventh resistor R7 is connected to the power source terminal VCC, a cathode of the third diode D3 is connected to a first end of the second switch K2, a cathode of the fourth diode D4 is connected to a first end of the third switch K3, a cathode of the fifth diode D5 is connected to the output terminal of the first comparator F1, an anode of the third diode D3, an anode of the fourth diode D4 and an anode of the fifth diode D5 are connected to a second end of the seventh resistor R7, and a second end of the seventh resistor R7 is connected to the control terminal of the fuse module 20. The seventh resistor R7 is used for voltage division.

With reference to fig. 2 and 4, the battery protection circuit further includes a delay module 60 and a second detection module 70. The delay module 60 is connected between the first detecting module 40 and the control terminal of the fuse module 20, and is configured to delay and output the output signal of the first detecting module 40 to the control terminal of the fuse module 20. The second detecting module 70 is connected to the delay module 60, and the second detecting module 70 is configured to detect the temperature of the switch module 10 and control the delay time of the delay module 60 to be shortened when the temperature of the switch module 10 is greater than or equal to the set temperature.

Specifically, the delay module 60 may be connected between the first detecting module 40 and the control end of the first switch K1, the delay module 60 may delay the output signal of the first detecting module 40 for a set time length and then output the signal to the control end of the first switch K1, and the fuse device 210 is controlled by the first switch K1, so as to implement a delay function and avoid false triggering. The second detecting module 70 may shorten the delay time of the delay module 60 when the temperature of the first transistor M1 and/or the second transistor M2 in the switch module 10 is greater than or equal to the set temperature, so that the delay time to the delay module 60 is less than the set time length, which may increase the control speed of the first detecting module 40 for the first switch K1 when the temperature of the first transistor M1 and/or the second transistor M2 is too high, so as to prompt the fuse device 210 to respond quickly, thereby achieving the effect of temperature anomaly protection.

With reference to fig. 2 and 4, further, the delay module 60 includes an eighth resistor R8 and a first capacitor C1, the eighth resistor R8 is connected between the first detecting module 40 and the control terminal of the fuse module 20, a first pole of the first capacitor C1 is connected between the eighth resistor R8 and the control terminal of the fuse module 20, and a second pole of the first capacitor C1 is grounded.

The second detecting module 70 includes a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a thermistor NTC, an optocoupler device 710, a second comparator F2 and a fourth switch K4, a first end of the ninth resistor R9 is connected to the power supply terminal VCC, a second end of the ninth resistor R9 is connected to the first end of the thermistor NTC, a second end of the thermistor NTC is grounded, a first comparison signal input terminal of the second comparator F2 is connected to the reference voltage Vref, a second comparison signal input terminal of the second comparator F2 is connected to the second end of the ninth resistor R9, a tenth resistor R10 is connected between an output terminal of the second comparator F2 and the second comparison signal input terminal, an eleventh resistor R11 is connected between an output terminal of the second comparator F2 and the power supply terminal VCC, an output terminal of the second comparator F2 is connected to the control terminal of the fourth switch K4, a first input terminal of the optocoupler device 710 is connected to the VCC, a first end of the optocoupler device 710 is connected to the fourth switch K4, a second end of the fourth switch K4 is grounded, a second input end of the optical coupler device 710 is connected to a first end of the eighth resistor R8, and a second output end of the optical coupler device 710 is connected to a second end of the eighth resistor R8.

The thermistor NTC is used for detecting the temperature of the switch module. The fourth switch K4 may be a transistor, such as a triode, a field effect transistor, or the like, in this embodiment, the fourth switch K4 may be set as a triode, a base of the triode may serve as a control terminal of the fourth switch K4, one of a collector and an emitter of the triode may serve as a first terminal of the fourth switch K4, and the other may serve as a second terminal of the fourth switch K4. The ninth resistor R9 and the eleventh resistor R11 are used for voltage division, and the tenth resistor R10 serves as a feedback resistor.

With reference to fig. 2 and fig. 4, on the basis of the above embodiments, optionally, the first detecting unit 410 further includes a first zener diode E1, a twelfth resistor R12, a thirteenth resistor R13, and a second capacitor C2. The first voltage-stabilizing diode E1 and the twelfth resistor R12 are sequentially connected in series between the first diode D1 and the control end of the second switch K2, the thirteenth resistor R13 is connected between the control end and the second end of the second switch K2, and the second capacitor C2 is connected in parallel with the thirteenth resistor R13. A fourteenth resistor R14 is further connected between the first end of the second switch K2 and the third diode D3. The first zener diode E1 is used for stabilizing voltage to improve the stability of the signal, so that the signal on the first zener diode E1 needs to reach a certain value to be valid, thereby reducing the probability of false triggering. The twelfth resistor R12 and the fourteenth resistor R14 are used for current limiting, and the thirteenth resistor R13 and the second capacitor C2 are used for filtering.

The second sensing unit 420 further includes a second zener diode E2, a fifteenth resistor R15, a sixteenth resistor R16, and a third capacitor C3. The second zener diode E2 and the fifteenth resistor R15 are sequentially connected in series between the second diode D2 and the control terminal of the third switch K3, the sixteenth resistor R16 is connected between the control terminal and the second terminal of the third switch K3, and the third capacitor C3 is connected in parallel with the sixteenth resistor R16. A seventeenth resistor R17 is connected between the first end of the third switch K3 and the fourth diode D4. The second zener diode E2 is used for stabilizing voltage to improve the stability of the signal, so that the signal on the second zener diode E2 needs to reach a certain value to be valid, thereby reducing the probability of false triggering. The fifteenth resistor R15 and the seventeenth resistor R17 are used for current limiting, and the sixteenth resistor R16 and the third capacitor C3 are used for filtering.

The third sensing unit 430 further includes an eighteenth resistor R18, a nineteenth resistor R19, a fourth capacitor C4, and a fifth capacitor C5. The eighteenth resistor R18 is connected between the third resistor R3 and the first comparison signal input terminal of the first comparator F1, and the nineteenth resistor R19 is connected between the sixth resistor R6 and the second comparison signal input terminal of the first comparator F1. A first pole of the fourth capacitor C4 is connected to the second comparison signal input terminal of the first comparator F1, and a second pole of the fourth capacitor C4 is grounded. The first pole of the fifth capacitor C5 is connected to the output terminal of the first comparator F1, and the second pole of the fifth capacitor C5 is grounded. A twentieth resistor R20 is also connected between the output terminal of the first comparator F1 and the fifth diode D5. The eighteenth resistor R18, the nineteenth resistor R19 and the twentieth resistor R20 are used for current limiting, and the fourth capacitor C4 and the fifth capacitor C5 are used for filtering.

The and circuit 440 further includes a sixth capacitor C6, a first terminal of the sixth capacitor C6 is connected to the second terminal of the seventh resistor R7, and a second terminal of the sixth capacitor C6 is grounded. The sixth capacitor C6 is used for filtering.

The second detection module 70 further includes a twenty-first resistor R21, a twenty-second resistor R22, and a seventh capacitor C7. The twenty-first resistor R21 is connected between the output terminal of the second comparator F2 and the control terminal of the fourth switch K4. A twenty-second resistor R22 is connected between the power supply terminal VCC and the first input terminal of the optocoupler device 710. A first pole of the seventh capacitor C7 is connected to the second comparison signal input terminal of the second comparator F2, and a second pole of the seventh capacitor C7 is grounded. The twenty-first resistor R21 is used for current limiting, the twenty-second resistor R22 is used for voltage division, and the seventh capacitor C7 is used for filtering.

Further, the battery protection circuit further includes a twenty-third resistor R23, a twenty-fourth resistor R24, a sixth diode D6, and a seventh diode D7. The twenty-third resistor R23 and the seventh diode D7 are connected in series between the eighth resistor R8 and the control terminal of the fuse module 20, the anode of the seventh diode D7 is connected to the twenty-third resistor R23, and the cathode of the seventh diode D7 is connected to the control terminal of the fuse module 20. A first terminal of the twenty-fourth resistor R24 is connected to the control terminal of the fuse module 20, and a second terminal of the twenty-fourth resistor R24 is connected to ground. The control module 50 is connected to the control terminal of the fuse module 20 through a sixth diode D6, an anode of the sixth diode D6 is connected to the control module 50, and a cathode of the sixth diode D6 is connected to the control terminal of the fuse module 20. The twenty-third resistor R23 and the twenty-fourth resistor R24 are used for limiting current, and the sixth diode D6 and the seventh diode D7 are used for preventing the signal from flowing backwards.

With reference to fig. 2 and fig. 4, the overall operation principle of the battery protection circuit is described by taking the first electrode of the battery pack 30 as the positive electrode, the second electrode of the battery pack 30 as the negative electrode, the first power supply terminal V1 as the positive electrode, the second power supply terminal V2 as the negative electrode, the gate of the first transistor M1 as the control terminal of the switch module 10, the first level signal is a high level signal, the second level signal is a low level signal, and the signals for controlling the first transistor M1, the second transistor M2, the first switch K1 to the fourth switch K4 to be turned on are all high level signals:

illustratively, when the battery pack 30 and the battery protection circuit are in an operating state, a load is connected between the first power supply terminal V1 and the second power supply terminal V2, the gate voltage signals of the first transistor M1 and the second transistor M2 are both low level signals, and the normal state of the first transistor M1 and the second transistor M2 at this time is an off state. The first detection module 40 detects a fault of the first transistor M1, an input end of the first detection unit 410 is connected to a gate voltage signal Vg of the first transistor M1, the gate voltage signal Vg is a low-level signal, the low-level signal may sequentially pass through the first diode D1, the first zener diode E1 and the twelfth resistor R12, and is filtered by the second capacitor C2 and the thirteenth resistor R13 to enter a control end of the second switch K2, so that the second switch K2 is turned off, an output end of the first detection unit 410 (i.e., a first end of the second switch K2) outputs a high-level signal, and the first input end of the and circuit 440 (i.e., a cathode of the third diode D3) inputs a high-level signal. In the case where the battery pack 30 and the battery protection circuit are subjected to an impact of an external signal, causing breakdown of the first transistor M1 and the second transistor M2, the first transistor M1 and the second transistor M2 are in a conductive state, the negative electrode of the battery pack 30 and the second power terminal V2 are in a conduction state, the input terminal of the second detection unit 420 receives the signal of the second power terminal V2, the signal is a low level signal which can pass through the second diode D2, the second zener diode E2 and the fifteenth resistor R15 in sequence, and enters the control terminal of the third switch K3 after being filtered by the third capacitor C3 and the sixteenth resistor R16, so that the third switch K3 is turned off, the output terminal of the second detection unit 420 (i.e., the first terminal of the third switch K3) outputs a high level signal, and the second input terminal of the and circuit 440 (i.e., the cathode of the fourth diode D4) inputs a high level signal. When the first transistor M1 and the second transistor M2 are in a conducting state, a current exists between the battery pack 30, the battery protection circuit and the load, the input terminal of the third detection unit 430 is connected to the current signal VRs, and by setting the values of the reference voltage Vref, the third resistor R3 and the fourth resistor R4, whether a current exists between the battery pack 30 and the switch module 10 can be detected by the third detection unit 430, for example, when the current signal VRs is greater than zero, the voltage at the second comparison signal input terminal of the first comparator F1 is greater than the voltage at the first comparison signal input terminal at this time, the first comparator F1 outputs a high-level signal, so that the third input terminal of the and gate circuit 440 (i.e., the cathode of the fifth diode D5) inputs a high-level signal. This has the advantage of ensuring that the detection results of the first detection unit 410 and the second detection unit 420 are measured under the condition that the current exists between the battery pack 30 and the switch module 10, which helps to avoid errors in the detection results. Thus, when the first transistor M1 and the second transistor M2 are broken down, high level signals are input to the first input terminal, the second input terminal, and the third input terminal of the and circuit 440, and the and circuit 440 outputs a high level signal, which is filtered and delayed by the eighth resistor R8 and the first capacitor C1 and then transmitted to the control terminal of the first switch K1, so that the first switch K1 is turned on, thereby triggering the fuse device 210 to fuse and protecting the battery pack 30.

Meanwhile, the thermistor NTC in the second detection module 70 may detect the temperatures of the first transistor M1 and the second transistor M2, and by setting the magnitude of the ninth resistor R9, it may be achieved that when the temperatures of the first transistor M1 and the second transistor M2 are greater than or equal to a set temperature, the voltage at the second comparison signal input end of the second comparator F2 is greater than the voltage at the first comparison signal input end, the second comparator F2 outputs a high level signal, so that the fourth switch K4 is turned on, thereby turning on the first input end and the first output end of the optocoupler 710, turning on the second input end and the second output end, and short-circuiting the eighth resistor R8, so as to shorten the delay time of the delay module 60 and prompt the fuse 210 to fuse and respond quickly.

In the case where the gate voltage signals of the first transistor M1 and the second transistor M2 are both low level signals, and the first transistor M1 and the second transistor M2 are in a normal state, i.e., an off state, the output terminal of the first detection unit 410 still outputs a high level signal, so that the first input terminal of the and circuit 440 still inputs a high level signal. When the first transistor M1 and the second transistor M2 are in an off state, the second electrode of the battery pack 30 and the second power supply terminal V2 are in an off state, and since a load is connected between the first power supply terminal V1 and the second power supply terminal V2, a signal of the second power supply terminal V2 is pulled up to be a signal of the first power supply terminal V1, that is, an anode signal of the battery pack 30, which is a high-level signal, the high-level signal may sequentially pass through the second diode D2, the second zener diode E2, and the fifteenth resistor R15, and be filtered through the third capacitor C3 and the sixteenth resistor R16 to enter the control terminal of the third switch K3, so that the third switch K3 is turned on, and the output terminal of the second detection unit 420 outputs a low-level signal, so that the second input terminal of the and circuit inputs a low-level signal. In the case where the first transistor M1 and the second transistor M2 are in the off state, there is no current between the battery pack 30, the battery protection circuit, and the load, and by setting the values of the reference voltage Vref, the third resistor R3, and the fourth resistor R4, it is possible to make the voltage at the second comparison signal input terminal of the first comparator F1 smaller than the voltage at the first comparison signal input terminal at this time and the first comparator F1 output a low level signal in the case where the current signal VRs is zero, so that the third input terminal of the and circuit 440 inputs a low level signal. Thus, when the first transistor M1 and the second transistor M2 are in a normal state, the first input terminal and the third input terminal of the and circuit 440 both input a high level signal, the second input terminal inputs a low level signal, the gate circuit 440 outputs a low level signal, the first switch K1 is turned off, and the fuse device 210 remains in its original state. Meanwhile, the first switch K1 may be controlled to be turned on or off by the control module 50 to control the fuse device 210.

According to the technical scheme of the embodiment of the invention, the state of the transistor in the switch module 10 is detected through the first detection module 40, and when the transistor in the switch module 10 is broken down and damaged due to the impact of an external signal on the battery pack 30 and the battery protection circuit, the first detection module 40 can control the first switch K1 to be switched on to trigger the fusing device 210 to fuse, so as to protect the battery pack 30.

The embodiment of the invention also provides a battery management system, which comprises a battery pack and the battery protection circuit in any embodiment of the invention, so that the battery management system has the corresponding functional structure and beneficial effect of the battery protection circuit, and the details are not repeated.

The embodiment of the invention also provides a control method of the battery protection circuit, which is used for controlling the battery protection circuit in any embodiment of the invention. Fig. 5 is a schematic flowchart of a control method of a battery protection circuit according to an embodiment of the present invention. Referring to fig. 5, the control method of the battery protection circuit specifically includes the steps of:

and S110, acquiring signals of a second power supply end and a control end of the switch module through the first detection module.

And S120, determining the conducting state of the switch module according to the signal of the second power supply end through the first detection module.

S130, the first detection module controls the fusing module to be disconnected when the signal of the control end of the switch module is an off level signal and the switch module is in a conducting state.

On the basis of the foregoing embodiment, optionally, the first detection module includes a first detection unit, a second detection unit, a third detection unit, and an and circuit; the input end of the first detection unit is connected with the control end of the switch module, and the output end of the first detection unit is connected with the first input end of the AND gate circuit; the input end of the second detection unit is connected with a second power supply end, the output end of the second detection unit is connected with the second input end of the AND gate circuit, the first electrode of the battery pack is connected with the first power supply end, the switch module is connected between the second electrode of the battery pack and the second power supply end, and a load is connected between the first power supply end and the second power supply end; the input end of the third detection unit is connected between the battery pack and the switch module, and the output end of the third detection unit is connected with the third input end of the AND gate circuit; and the output end of the AND gate circuit is connected with the control end of the fusing module. Correspondingly, steps S120 and S130 specifically include:

outputting a first level signal when the signal of the control end of the switch module is a turn-off level signal and outputting a second level signal when the signal of the control end of the switch module is a turn-on level signal through a first detection unit;

outputting a first level signal when the signal of the second power supply end is the second electrode signal of the battery pack and outputting a second level signal when the signal of the second power supply end is the first electrode signal of the battery pack through a second detection unit;

outputting a first level signal when the current between the battery pack and the switch module is greater than or equal to a set current and outputting a second level signal when the current between the battery pack and the switch module is less than the set current through a third detection unit;

when the signals of the first input end, the second input end and the third input end of the AND gate circuit are first level signals, the first level signals are output to the control end of the fusing module to control the fusing module to be disconnected.

the control method of the battery protection circuit further includes:

the temperature of the switch module is detected through the second detection module, and the delay time of the delay module is controlled to be shortened when the temperature of the switch module is larger than or equal to the set temperature.

The embodiment of the invention also provides a battery management system, which applies the control method of the battery protection circuit in any embodiment. According to the battery management system provided by the embodiment of the invention, the first detection module is used for acquiring the signals of the second power supply end and the control end of the switch module, the conducting state of the switch module is determined according to the signal of the second power supply end, and the switch module is determined to be broken down and damaged when the signal of the control end of the switch module is a turn-off level signal and the switch module is in the conducting state, so that the first detection module is used for controlling the fuse module to be disconnected, the fuse module is triggered to be normally started under the conditions that the battery pack and the battery protection circuit are impacted by external signals and the like, the protection effect under the abnormal state is achieved, and the safety and reliability of the battery pack and the battery protection circuit are enhanced.

It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in the present invention may be executed in parallel, sequentially, or in different orders, and are not limited herein as long as the desired results of the technical solution of the present invention can be achieved.

The above-described embodiments should not be construed as limiting the scope of the invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made in accordance with design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A battery protection circuit, comprising:

2. The battery protection circuit of claim 1, wherein the fuse module comprises a first switch and a fuse device;

the fuse device includes a three-terminal fuse.

3. The battery protection circuit of claim 1, further comprising a control module connected to the battery pack, the control terminal of the switch module, and the control terminal of the fuse module for controlling the switch module and the fuse module;

4. The battery protection circuit of claim 1, wherein the first detection module comprises a first detection unit, a second detection unit, a third detection unit and an and gate circuit;

5. The battery protection circuit according to claim 4, wherein the first detection unit comprises a first diode, a first resistor and a second switch, an anode of the first diode is connected to the control terminal of the switch module, a cathode of the first diode is connected to the control terminal of the second switch, a first terminal of the second switch is connected to a power supply terminal through the first resistor, and a second terminal of the second switch is grounded;

6. The battery protection circuit according to any of claims 1-5, further comprising a delay module and a second detection module;

7. The battery protection circuit of claim 6, wherein the delay module comprises an eighth resistor and a first capacitor, the eighth resistor is connected between the first detection module and the control terminal of the fuse module, a first pole of the first capacitor is connected between the eighth resistor and the control terminal of the fuse module, and a second pole of the first capacitor is grounded;

8. A method of controlling a battery protection circuit, the battery protection circuit comprising: the device comprises a switch module, a fusing module and a first detection module; the switch module, the fusing module and the battery pack are connected between a first power supply end and a second power supply end; the switch module is arranged close to the second power supply end and is used for responding to a signal of the control end of the switch module to be switched on or switched off so as to control charging and discharging of the battery pack; the fusing module is used for responding to the signal disconnection of the control end of the fusing module; the first detection module is connected with the second power supply end, the control end of the switch module and the control end of the fusing module;

9. The control method of the battery protection circuit according to claim 8, wherein the battery protection circuit further comprises a delay module and a second detection module; the time delay module is connected between the first detection module and the control end of the fusing module, and the second detection module is connected with the time delay module;

the control method of the battery protection circuit further includes:

and the second detection module detects the temperature of the switch module and controls the delay time of the delay module to be shortened when the temperature of the switch module is greater than or equal to a set temperature.

10. A battery management system comprising a battery pack and the battery protection circuit according to any one of claims 1 to 7, or a control method applying the battery protection circuit according to any one of claims 8 to 9.