KR20210044293A - Battery protection circuit, battery management system, battery device, and control method thereof - Google Patents

Abstract

The present invention provides a battery protection circuit, wherein the battery protection circuit is electrically connected between a battery cell unit and an external port to form a power supply circuit, and the battery protection circuit comprises a first protection unit, a second protection unit, and A detection switch unit, wherein the first protection unit is electrically connected between the battery cell unit and the second protection unit, the detection switch unit is installed at a preset position of the battery cell unit, and the detection switch The unit is electrically connected to the battery cell unit, and when the detection switch unit is triggered to turn on, and the first protection unit turns the power supply circuit on, the second protection unit To protect the battery device. The present invention also provides a battery management system, a battery device, and a control method thereof. The battery protection circuit provided in the present invention has advantages of high safety, wide application range, and low cost.

Description

Battery protection circuit, battery management system, battery device, and control method thereof

This application claims the priority of the Chinese patent application filed on June 17, 2020, the application number is 202010555943.6, the invention name is "battery protection circuit, battery management system, battery device and its control method", the entire contents of this application Is incorporated by reference in.

The present invention relates to the field of battery technology, and more particularly, to a battery protection circuit, a battery management system including a battery protection circuit, a battery device, and a control method thereof.

Currently, lithium-ion batteries are widely used as an important energy source for people, and play a very important role in the field of electronic communication or transportation, and have a wide application prospect. The safety of lithium-ion batteries is also an issue that cannot be ignored.

Lithium-ion batteries are generally safe when used according to the norm, but can be a potential hazard if internal or mechanical errors occur. For example, when a battery is in malicious conditions such as overcharging, crushing, high temperature or short circuit, it can lead to overheating, smoke generation, and even ignition. In the prior art, a lithium-ion battery protection chip can monitor the charging and discharging process and intervene if there is a possibility of exceeding the risk of the safe operating range of the battery in the process. However, if the lithium-ion battery protection chip fails, it cannot warn the battery of danger.

In view of this, there is a need to provide a battery protection circuit capable of protecting a battery cell unit, a battery management system including a battery protection circuit, a battery device, and a control method thereof.

An embodiment of the present invention provides a battery protection circuit, wherein the battery protection circuit is electrically connected between a battery cell unit and an external port to form a power supply circuit, and the battery protection circuit comprises a first protection unit and a second protection unit. A protection unit and a detection switch unit, wherein the first protection unit is electrically connected between the battery cell unit and the second protection unit, and the detection switch unit is installed at a preset position of the battery cell unit, , The detection switch unit is electrically connected to the second protection unit, the detection switch unit is triggered to turn on, and the first protection unit turns the power supply circuit on, The battery unit is protected by controlling the second protection unit.

According to some embodiments of the present invention, the second protection unit includes a fuse, a first resistor, and a first switch, and a first terminal of the fuse is electrically connected to a positive electrode of the battery cell unit, and The second terminal is electrically connected to the second terminal of the first switch through the first resistor, the third terminal of the fuse is electrically connected to the positive electrode of the external port, and the first terminal of the first switch is It is electrically connected to the sensing switch unit, a second terminal of the first switch is grounded, and a third terminal of the first switch is electrically connected to a second terminal of the fuse.

According to an embodiment of the present invention, the sensing switch unit is a temperature switch, and when the temperature switch detects that the temperature of the battery cell unit exceeds a preset temperature, the temperature switch is triggered to be turned on, so that the first The switch is triggered to be turned on to heat the first resistor, and cut the fuse to protect the battery cell unit.

According to an embodiment of the present invention, the sensing switch unit is a micro switch, and when the battery cell unit is pressed by thermal expansion, the micro switch is triggered to be turned on, and the first switch is triggered to be turned on. The resistor is heated and the fuse is blown to protect the battery cell unit.

According to an embodiment of the present invention, the battery protection circuit further includes a third protection unit, and the third protection unit is electrically connected between the battery cell unit and the second protection unit.

According to an embodiment of the present invention, the detection switch unit is triggered to be turned on, the first protection unit turns the power supply circuit on, and the third protection unit does not trigger the second protection unit. In this case, the battery cell unit is protected by controlling the second protection unit.

An embodiment of the present invention provides a battery management system including the battery protection circuit.

According to an embodiment of the present invention, when the battery management system controls the battery cell unit and is discharged with a preset current, the second protection unit is triggered when the detection switch unit is turned on. Protect

According to an embodiment of the present invention, the second protection unit includes a fuse, and a difference between the rated current of the fuse and the preset current is less than or equal to a current threshold.

An embodiment of the present invention provides a battery device, wherein the battery device includes a battery cell unit, and the battery device further includes a battery protection circuit as described above, wherein the battery protection circuit comprises the battery cell unit. It is used to protect.

An embodiment of the present invention provides a method for controlling a battery device, wherein the battery device includes a battery cell unit and a battery protection circuit electrically connected to the battery cell unit, and the battery protection circuit comprises the battery cell unit and Electrically connected between the external ports to form a power supply circuit, the battery protection circuit comprises a first protection unit, a second protection unit and a detection switch unit, the method,

And protecting the battery cell unit by controlling the second protection unit when the detection switch unit is triggered to be turned on and the first protection unit turns the power supply circuit on.

According to an embodiment of the present invention, the battery protection circuit further comprises a third protection unit electrically connected between the battery cell unit and the second protection unit, and the method comprises:

When the detection switch unit is triggered to be turned on, the first protection unit turns the power supply circuit on, and when the third protection unit does not trigger the second protection unit, the second protection unit is controlled to And protecting the battery cell unit.

According to an embodiment of the present invention, the battery device includes a battery management system, and the method includes:

When the battery management system controls the battery cell unit to be discharged with a preset current, when the detection switch unit is triggered to be turned on, the step of protecting the battery cell unit by controlling the second protection unit is further performed. Includes.

According to an embodiment of the present invention, the second protection unit includes a fuse, and a difference between the rated current of the fuse and the preset current is less than or equal to a current threshold.

According to a battery management system including a battery protection circuit and a battery protection circuit provided in an embodiment of the present invention, a detection switch unit is installed at a preset position of the battery cell unit, and the detection switch unit is the second protection. When the first protection unit is electrically connected to the unit and is triggered so that the detection switch unit is turned on without triggering the second protection unit, the second protection unit is controlled to protect the battery cell unit.

The present invention can effectively prevent fire and explosion accidents of a battery cell unit due to overcharge, overdischarge, or large multi-discharge close to the rated current of a fuse in case of a single point failure of the battery management system. The battery protection circuit provided in the present invention has advantages of high safety, wide application range, and low cost.

1 is a block diagram of a battery device according to a first embodiment of the present invention.
2 is a block diagram of a battery device according to a second embodiment of the present invention.
3 is a circuit diagram of a first embodiment of a battery protection circuit in the battery management system of FIG. 1.
4 is a circuit diagram of a second embodiment of a battery protection circuit in the battery management system of FIG. 1.
5 is a flowchart of a method for controlling a battery device according to a first embodiment of the present invention.
Hereinafter, in the detailed description for carrying out the invention, the present invention will be described in detail with reference to the accompanying drawings.

In order for those skilled in the art to better understand the solutions of the present invention, the technical solutions of the embodiments of the present invention will be described clearly and completely below with reference to the drawings of the embodiments of the present invention. Apparently, the described embodiments are only a part of the embodiments of the present invention, not all.

In the description of the embodiments of the present invention, it should be noted that the term "connection" is to be understood in a broad sense unless clearly defined and limited otherwise. For example, it may be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection, an electrical connection, or it can communicate with each other. It may be a direct connection, an indirect connection through a centering component, an internal connection between two elements, or an interaction between two elements. The specific meaning of the terms described above in the present invention can be understood by those skilled in the art according to specific circumstances.

In the specification and claims of the present invention and in the foregoing drawings, the terms “first”, “second” and “third” are used to distinguish between different objects rather than describing a particular order. Also, the term "comprising" and variations thereof include non-exclusive inclusion.

Referring to Figure 1, Figure 1 is a block diagram according to a preferred embodiment of the battery device of the present invention. The battery device 100 includes a battery cell unit 200 and a battery protection circuit 300 electrically connected to the battery cell unit 200. The battery protection circuit 300 is located in the battery management system 400 and protects the battery cell unit 200 when the battery management system 400 controls charging and discharging of the battery cell unit 200. Is used for The battery protection circuit 300 is electrically connected between the battery cell unit 200 and the external port 500 to form a power supply circuit, and the battery protection circuit 300 turns on or off the power supply circuit. (turn off) is controlled, and thus, when the battery management system 400 controls charging and discharging of the battery cell unit 200, the battery cell unit 200 is protected.

The battery protection circuit 300 includes a first protection unit 30, a second protection unit 31, and a detection switch unit 32.

Specifically, in the embodiment of the present invention, the first protection unit 30 is electrically connected between the battery cell unit 200 and the second protection unit 31. The detection switch unit 32 is installed at a preset position of the battery cell unit 200, and the detection switch unit 32 is electrically connected to the second protection unit 31. In the normal use state, the sensing switch unit 32 is in an off state. When the detection switch unit 32 is turned on without the first protection unit 30 blocking the power supply circuit, the second protection unit 31 is triggered to protect the battery cell unit 200. I can. It can be seen that a preset position may be set according to the difference between the sensing switch units 32. For example, when the sensing switch unit 32 is a temperature switch, the preset position is a position at which the highest temperature point on the surface of the battery cell unit 200 is located. When the sensing switch unit 32 is a micro switch, the preset position is the position that is most easily expanded on the surface of the battery cell unit 200. It should be noted that the location of the highest temperature point or the point where the battery cell unit 200 is most easily expanded is determined when the battery cell unit 200 is shipped from the factory. For example, by performing thermal simulation and testing according to the battery system, chemical composition and structure of the battery cell unit 200, the maximum temperature of the battery cell unit 200 or the location of the most easily expanded point in the battery system You can get it. It can be appreciated that the location of the highest surface temperature of the battery device 200 of different battery systems or the point of most easily expanding is not the same. In one embodiment, the first protection unit 30 includes a plurality of first protection chips for protecting each cell of the battery cell unit 200.

In an embodiment, referring to FIG. 3, the second protection unit 31 includes a fuse 310, a first resistor R1, and a first switch Q1. The fuse 310 is a three terminal fuse. The first terminal of the fuse 310 is connected to the positive electrode of the battery cell unit 200, and the second terminal of the fuse 310 is the first terminal of the first switch Q1 through the first resistor R1. 2, the third terminal of the fuse 310 is connected to the positive electrode of the external port 500, and the first terminal of the first switch Q1 is electrically connected to the sensing switch unit 32 The third terminal of the first switch Q1 is electrically connected to the second terminal of the fuse 310, and the second terminal of the first switch Q1 is grounded. The first switch Q1 may be an N-type field effect transistor. The first terminal, the second terminal, and the third terminal of the first switch Q1 correspond to the gate, source, and drain of the N-type field effect transistor, respectively.

In one embodiment, the sensing switch unit 32 is used to sense the temperature or expansion range of the battery cell unit 200 or the pressure when it is compressed. For example, the detection switch unit 32 is a temperature switch capable of detecting a temperature of a preset position of the battery cell unit 200 and comparing the detected temperature with a preset temperature. When the sensed temperature is higher than a preset temperature, the temperature switch is turned on, and accordingly, the first switch (Q1) is triggered to be turned on, thereby heating the first resistor (R1) and opening the fuse (310). It cuts off to protect the battery cell unit 200.

In another embodiment, the sensing switch unit 32 is a micro switch. When the battery cell unit 200 is heated, it expands, and when the battery cell unit 200 is expanded and compressed (for example, when the battery cell unit 200 is compressed by the housing), the micro switch is When turned on, the first switch Q1 is triggered to turn on, and the first resistor R1 is heated to blow the fuse 310 to protect the battery cell unit 200.

It should be noted that the sensing switch unit 32 can also be replaced with other components or mechanical components having similar temperature switch characteristics. For example, the sensing switch unit 32 may be a displacement sensing switch for sensing the thermal expansion range of the battery cell unit 200. When the detected range exceeds a preset range, the displacement detection switch is triggered to be turned on, and as a result, the first switch Q1 is turned on, the first resistor R1 is heated and the fuse 310 is blown. The battery cell unit 200 is protected.

In one embodiment, a positive electrode of the external port 500 may be electrically connected to a positive electrode of a charger (not shown), and a negative electrode of the external port 500 may be electrically connected to a negative electrode of the charger.

In one embodiment, the battery protection circuit 300 further includes a third protection unit 33, as shown in FIG. 2. The third protection unit 33 is electrically connected between the battery cell unit 200 and the second protection unit 31. When the first protection unit 30 does not block the power supply circuit and the third protection unit 33 does not trigger the second protection unit 31 and the detection switch unit 32 is turned on, the The second protection unit 31 is triggered to protect the battery cell unit 200. The third protection unit 33 includes a plurality of second protection chips for double protection of each cell of the battery cell unit 200 in combination with the first protection unit 30.

In one embodiment, when the first protection unit 30 is ineffective and the third protection unit 33 is triggered, a driving signal is output to the second protection unit 31 to output the second protection unit 31 ) May be triggered to protect the battery cell unit 200. When the first protection unit 30 is ineffective and the third protection unit 33 is also ineffective, the second protection unit 31 is triggered through the detection switch unit 32 to trigger the battery cell unit ( 200) can be protected.

That the first protection unit 30 is ineffective means that the first protection unit 30 does not cut off the power supply circuit when the parameter of the battery cell unit 200 is equal to or greater than a preset first parameter. (For example, blocking the second switch Q2 or the third switch Q3). The parameters of the battery cell unit 200 may be current, voltage, or temperature. When the parameter is a temperature, it can be understood that a preset first temperature corresponding to the first protection unit 30 will be lower than a temperature when the detection switch unit 32 is triggered. For example, the preset first temperature corresponding to the first protection unit 30 is 50°C, and the temperature when the detection switch unit 32 is triggered is the battery cell unit 200 tolerate. It is the highest temperature that can be (for example, 70°C).

The ineffectiveness of the third protection unit 33 means that the first protection unit 30 does not trigger the second protection unit 31 when the parameter of the battery cell unit 200 is equal to or greater than a preset second parameter. You can understand that it means not. The preset second parameter is greater than the preset first parameter, and is less than a threshold value when the detection switch unit 32 is triggered.

For example, when the voltage of the battery cell unit 200 exceeds a preset voltage and reaches a voltage threshold for triggering the first protection unit 30, the first protection unit 30 triggers The battery cell unit 200 may be protected.

When the voltage of the battery cell unit 200 exceeds a preset voltage and reaches a voltage threshold for triggering the first protection unit 30, but the first protection unit 30 is ineffective, the battery cell The voltage threshold for checking whether the voltage of the unit 200 reaches the voltage threshold for triggering the third protection unit 33, and the voltage of the battery cell unit 200 for triggering the third protection unit 33 When the value is reached, the third protection unit 33 triggers to output a driving signal to the second protection unit 31, and controls the second protection unit 31 to control the battery cell unit 200. Can be protected.

When the voltage of the battery cell unit 200 exceeds a preset voltage and reaches a voltage threshold for triggering the first protection unit 30, but the first protection unit 30 is ineffective, the battery cell The voltage threshold for checking whether the voltage of the unit 200 reaches the voltage threshold for triggering the third protection unit 33, and the voltage of the battery cell unit 200 for triggering the third protection unit 33 When the value is reached, but the third protection unit 33 is ineffective, after the detection switch unit 32 is turned on, a driving signal is output to the second protection unit 31, and the second protection unit 33 is The battery cell unit 200 may be protected by controlling the protection unit 31.

3, FIG. 3 is a circuit diagram of a battery protection circuit 300 according to a first embodiment of the present invention.

In one embodiment, it is described that the first protection unit 30 includes three first protection chips, and each of the first protection chips is connected to four battery cells. For example, the first protection unit 30 includes a first protection chip IC1, a first protection chip IC2, a first protection chip IC3, a second resistor R2, and a third resistor R3. ... including the seventh resistor R7. The battery cell unit 200 includes a first battery cell B1, a second battery cell B2, ... a twelfth battery cell B12. In one embodiment, the first protection chip IC1 is connected to the first to fourth battery cells B1 to B4 to provide the first to fourth battery cells B1 to B4. Protect. For example, one end of the second resistor R2 is connected to a positive electrode of the first battery cell B1, and the other end of the second resistor R2 is connected to a negative electrode of the first battery cell B1. do. One end of the second resistor R2 is also connected to a first pin CV0 of the first protection chip IC1, and the other end of the second resistor R2 is a second It is also connected to pin (CV1). One end of the fifth resistor R5 is connected to the positive electrode of the fourth battery cell B4, and the other end of the fifth resistor R5 is connected to the negative electrode of the fourth battery cell B4. One end of the fifth resistor R5 is also connected to the third pin CV3 of the first protection chip IC1, and the other end of the fifth resistor R5 is also It is connected to pin (CV4).

Similarly, the first protection chip IC2 is connected to the fifth to eighth battery cells B5 to B8 to protect the fifth to eighth battery cells B5 to B8. It should be noted that. The first protection chip IC3 is connected to the ninth battery cells B9 to twelfth battery cells B12 to protect the ninth battery cells B9 to twelfth battery cells B12. A specific connection method is similar to a connection method between the first protection chip IC1 and the first to fourth battery cells B1 to B4, and thus will not be described in detail here. The first protection unit 30 may include N number of first protection chips, and the number of first protection chips is not limited in the present invention.

The first protection unit 30 further includes a second switch Q2, a third switch Q3, and a resistor R0. The resistor R0 is used to collect a current of a power supply circuit, that is, a current flowing through the battery cell unit 200. In this embodiment, one end of the resistor R0 is connected to the negative electrode of the first battery cell B1 and the other end of the resistor R0 is connected to the second switch Q2. One end of the resistor R0 is also connected to the SRP pin of the first protection chip IC1, and the other end of the resistor R0 is also connected to the SRN pin of the first protection chip IC1. The first protection chip IC1 may sense a voltage of the resistor R0 and calculate a current flowing through the battery cell unit 200 according to the voltage and a resistance value of the resistor R0.

The first terminal of the second switch Q2 is connected to the discharge pin DSG of the first protection chip IC1, the second terminal of the second switch Q2 is connected to the resistor R0, and , The third terminal of the second switch Q2 is connected to the second terminal of the third switch Q3, and the first terminal of the third switch Q3 is charged with the first protection chip IC1. It is connected to a pin CHG, a third terminal of the third switch Q3 is connected to a third terminal of the second switch Q2, and a second terminal of the third switch Q3 is the external port It is connected to the cathode of 500.

The second switch Q2 and the third switch Q3 may be N-type field effect transistors. The first, second, and third terminals of the second switch Q2 and the third switch Q3 correspond to the gate, source, and drain of the N-type field effect transistor, respectively.

In this embodiment, the first protection chip IC1, the first protection chip IC2, and the first protection chip IC3 are cascaded to control the second switch Q2 and the third switch Q3. By doing so, it is possible to control the on and off of the power supply circuit. Specifically, the charging pin CHG of the first protection chip IC3 is connected to the charge enable pin CTRC of the first protection chip IC2, and the discharge pin DSG of the first protection chip IC3 ) Is connected to the discharge enable pin CTRD of the first protection chip IC2. The charging pin CHG of the first protection chip IC2 is connected to the charging enable pin CTRC of the first protection chip IC1, and the discharge pin DSG of the first protection chip IC2 is 1 is connected to the discharge enable pin CTRD of the protection chip IC1, the charging pin CHG of the first protection chip IC1 is connected to the third switch Q3, and the first protection chip ( The discharge pin DSG of IC1 is connected to the second switch Q2. When any one of the first protection chip IC1 to the first protection chip IC3 detects overcharging or overdischarging of the battery cell unit 200, the charge enable pin CTRC or the discharge enable pin CTRD is Battery cell unit 200 by activating the charging pin (CHG) or the discharging pin (DSG) through outputting a driving signal and controlling the second switch (Q2) or the third switch (Q3) to be turned off. You can achieve the purpose of protecting it.

In the normal use state, the detection switch unit 32 is in an off state, and the second terminal of the fuse 310 of the second protection unit 31 is connected to the second terminal of the first switch Q1 to provide a power supply circuit. Works normally. When the first protection unit 30 of the power supply circuit is ineffective, the first protection unit 30 turns off the second switch Q2 or the third switch Q3 so that the power supply circuit is cut off. Do not control. When the battery cell unit 200 is abnormal due to overvoltage or undervoltage (for example, when the temperature of the battery cell rises to a threshold value, the battery cell expands thermally, or the battery cell is compressed by heat), the detection switch Unit 32 is triggered to turn on. As a result, the first switch Q1 is triggered to turn on to heat the first resistor, cut off the fuse, and cut off the power supply circuit to avoid continuous charging or discharging, and fire of the battery cell unit 200 Or prevent explosion.

In one embodiment, when the battery management system 400 controls the battery cell unit 200 to be discharged with a preset current (eg, 3C-6C current is continuously discharged), the fuse 310 is blown. Can't lose That is, the battery management system 400 controls the battery cell unit 200 to be continuously discharged at a rated current close to the fuse 310. An abnormality occurs in the battery cell unit 200 due to continuous large-scale discharge (for example, the temperature of the battery cell rises to a temperature threshold that the sensing switch unit can withstand, or the thermal expansion range of the battery cell increases the threshold value. Or the pressure at which the battery cell is squeezed by heat is greater than the pressure threshold), and the sensing switch unit 32 is triggered to turn on. As a result, the first switch (Q1) is triggered to turn on to heat the first resistor (R1) and the fuse 310 is blown so that the battery cell 200 continues to be discharged to prevent fire, explosion, and other dangerous accidents. Prevents triggering. In one embodiment, the difference between the rated current of the fuse 310 and the preset current is less than or equal to a current threshold.

Referring to FIG. 4, FIG. 4 is a circuit diagram of a battery protection circuit 300 according to a second embodiment of the present invention.

Differences between the battery protection circuit 300 of the present embodiment and the battery protection circuit 300 of the first embodiment are as follows.

In one embodiment, the battery protection circuit 300 further includes a third protection unit 33. The third protection unit 33 is electrically connected between the battery cell unit 200 and the second protection unit 31. The third protection unit 33 includes a plurality of second protection chips for double protection of each cell of the battery cell unit 200 in combination with the first protection unit 30.

For example, it is described that the first protection unit 33 includes three second protection chips, and each of the second protection chips is connected to four battery cells. The third protection unit 33 includes a second protection chip IC1', a second protection chip IC2', a second protection chip IC3', a second resistor R1', and a third resistor R2'. ) ... includes a seventh resistor R7' In one embodiment, the second protection chip IC1' is connected to the first to fourth battery cells B1 to B4 Protects the first to fourth battery cells B1 to B4. For example, the first pin VSS of the second protection chip IC1' is a negative electrode of the first battery cell B1. And a second pin V1 of the second protection chip IC1 ′ is connected to a positive electrode of the first battery cell B1 through a resistor R1 ′, and the second protection chip IC1 ′ The third pin V4 and the fourth pin V5 of) are connected to the positive electrode of the fourth battery cell B4 through a resistor R2'.

Similarly, the second protection chip IC2' is connected to the fifth to eighth battery cells B5 to B8 to protect the fifth to eighth battery cells B5 to B8. It should be noted that. The second protection chip IC3' is connected to the ninth battery cells B9 to twelfth battery cells B12 to protect the ninth battery cells B9 to twelfth battery cells B12. A specific connection method is similar to that of the connection method between the second protection chip IC1 ′ and the first to fourth battery cells B1 to B4, and thus will not be described in detail here. The third protection unit 33 may include N number of first protection chips, and the number of first protection chips is not limited in the present invention.

In this embodiment, the output pin OUT of the second protection chip IC1', the output pin OUT of the second protection chip IC2', and the output pin OUT of the second protection chip IC3' ) Is connected, and then the first terminal (eg, F1-C) of the first switch Q1 is connected. When the first protection unit 30 (that is, the first protection chips IC1 to IC3) is ineffective, the battery cell unit 200 may be overcharged or overdischarged, and through the third protection unit 33 By outputting a driving signal to the first switch Q1, turning on the first switch Q1, heating the first resistor R1 to blow the fuse 310, the battery cell unit 200 This prevents it from continuing to charge or discharge, causing fire and explosion accidents.

In the normal use state, the sensing switch unit 32 is in an off state, and the power supply circuit operates normally. When both the first protection unit 30 and the third protection unit 33 are ineffective, that is, the first protection unit 30 is turned off the second switch Q2 or the third switch Q3. When the power supply circuit is not controlled to be cut off, and the third protection unit 33 does not trigger the second protection unit 31, the battery cell unit 200 is An abnormality occurs in the unit 200 (for example, the temperature of the battery cell rises to a temperature threshold that the sensing switch unit can withstand, the thermal expansion range of the battery cell exceeds the threshold value, or the battery cell is compressed by heat. Pressure is greater than the pressure threshold), and the detection switch unit 32 is triggered to be turned on, and thus, the first switch Q1 is triggered to be turned on, so that the first resistor R1 is It is heated and cuts off the fuse 310 to protect the battery cell unit 200 and prevent accidents such as fire and explosion.

Similarly, when the battery management system 400 controls the battery cell unit 200 to be discharged with a preset current, for example, if the 3C-6C current is continuously discharged, the fuse cannot be blown. That is, the battery management system 400 continuously discharges at a current close to the rated current of the fuse 310, and a difference between the rated current of the fuse 310 and the preset current is equal to or less than a current threshold. An abnormality occurs in the battery cell unit 200 due to continuous large rate discharge (for example, the temperature of the battery cell rises to a temperature threshold that the sensing switch unit can withstand, or the thermal expansion range of the battery cell increases the threshold value. Or the pressure at which the battery cell is squeezed by heat is greater than the pressure threshold), and the sensing switch unit 32 is triggered to turn on. As a result, the first switch (Q1) is triggered to turn on to heat the first resistor (R1), the fuse 310 is blown, and the battery cell unit 200 is continuously discharged, resulting in fire, explosion, and other dangerous accidents. To prevent

As shown in FIG. 5, FIG. 5 is a flowchart of a method for controlling a battery device according to an embodiment of the present invention. The method of controlling the battery device includes the following steps.

Step S1: When the detection switch unit is triggered to be turned on and the first protection unit turns the power supply circuit on, the battery cell unit 200 is protected by controlling the second protection unit.

In this embodiment, the battery device 100 includes a battery cell unit 200 and a battery protection circuit 300 electrically connected to the battery cell unit 200, and the battery protection circuit 300 is the battery The cell unit 200 is electrically connected between the external port 500 to form a power supply circuit, and the battery protection circuit 300 includes a first protection unit 30, a second protection unit 31, and a detection switch. It includes a unit 32.

In the normal use state, the detection switch unit 32 is in an off state, and the second terminal of the fuse 310 of the second protection unit 31 is connected to the second terminal of the first switch Q1 to provide a power supply circuit. Works normally. When the first protection unit 30 of the power supply circuit is ineffective, the first protection unit 30 turns off the second switch Q2 or the third switch Q3 so that the power supply circuit is cut off. Do not control. When the battery cell unit 200 is abnormal due to overvoltage or undervoltage (for example, when the temperature of the battery cell rises to a threshold value, the battery cell expands thermally, or the battery cell is compressed by heat), the detection switch The unit 32 is triggered to be turned on, thereby protecting the battery cell unit 200 by controlling the second protection unit. That is, the first switch Q1 of the second protection unit is triggered to turn on to heat the first resistor, cut off the fuse, and cut off the power supply circuit to avoid continuous charging or discharging, and the battery cell ( 200) to prevent fire or explosion.

Step S2: The detection switch unit 32 is triggered to be turned on, the first protection unit 30 does not block the power supply circuit, and the third protection unit 33 turns on the second protection unit 31 ) Is not triggered, controlling the second protection unit 31 to protect the battery cell unit 200.

In the normal use state, the sensing switch unit 32 is in an off state, and the power supply circuit operates normally. When both the first protection unit 30 and the third protection unit 33 are ineffective, that is, the first protection unit 30 is turned off the second switch Q2 or the third switch Q3. When the power supply circuit is not controlled to be cut off, and the third protection unit 33 does not trigger the second protection unit 31, the battery cell unit 200 is An abnormality occurs in the unit 200 (for example, the temperature of the battery cell rises to a temperature threshold that the sensing switch unit can withstand, the thermal expansion range of the battery cell exceeds the threshold value, or the battery cell is compressed by heat. Pressure is greater than the pressure threshold), and the detection switch unit 32 is triggered to be turned on, and thus, the first switch Q1 is triggered to be turned on, so that the first resistor R1 is It is heated and cuts off the fuse 310 to protect the battery cell unit 200 and prevent accidents such as fire and explosion.

In one embodiment, the method further includes the following steps. When the battery management system 400 controls the battery cell unit 200 and is discharged with a preset current, when the detection switch unit 32 is triggered to be turned on, the second protection unit 31 Control to protect the battery cell unit 200.

In one embodiment, when the battery management system 400 controls the battery cell unit 200 to be discharged with a preset current (eg, 3C-6C current is continuously discharged), the fuse 310 is blown. Can't lose That is, the battery management system 400 controls the battery cell unit 200 to be continuously discharged at a rated current close to the fuse 310. An abnormality occurs in the battery cell unit 200 due to continuous large rate discharge (for example, the temperature of the battery cell rises to a temperature threshold that the sensing switch unit can withstand, or the thermal expansion range of the battery cell increases the threshold value. Or the pressure at which the battery cell is squeezed by heat is greater than the pressure threshold), and the sensing switch unit 32 is triggered to turn on. As a result, the first switch (Q1) is triggered to turn on to heat the first resistor (R1), the fuse 310 is blown, and the battery cell unit 200 is continuously discharged, resulting in fire, explosion, and other dangerous accidents. To prevent In one embodiment, the difference between the rated current of the fuse 310 and the preset current is less than or equal to a current threshold.

According to the battery management system 400 including the battery protection circuit 300 and the battery protection circuit 300 provided in the above-described embodiment, the detection switch unit 32 is located at a preset position of the battery cell unit 200. ) Is installed, and the detection switch unit 32 is electrically connected to the second protection unit 31, and the first protection unit 30 does not trigger the second protection unit 31 and detects the When the switch unit 32 is triggered to be turned on, the second protection unit 31 is controlled to protect the battery cell unit 200. The present invention can effectively prevent fire and explosion accidents of the battery cell unit 200 due to overcharging, overdischarging, or discharging at a large magnification close to the rated current of the fuse 310 in the event of a single point failure of the battery management system 400. . The battery protection circuit 300 provided in the present invention has advantages of high safety, wide application range, and low cost.

For those of ordinary skill in the art, the above implementation manner is used only to describe the present invention, and does not limit the present invention, as long as it is within the scope of the essential spirit of the present invention, appropriate for the above embodiment. Changes and changes are included within the scope of the claims of the present invention.

Battery unit 100
Battery cell unit 200
Battery protection circuit 300
Battery Management System 400
External port 500
First protection unit 30
Second protection unit 31
Detection switch unit 32
3rd protection unit 33
First resistor R1
Resistance R0, R1' to R7'
Fuse 310
1st switch Q1
2nd switch Q2
3rd switch Q3
1st protection chip IC1、IC2、IC3
Second protection chip IC1', IC2', IC3'
2nd resistance ~ 7th resistance R2 ~ R7
1st battery cell-12th battery cell B1-B12
1st pin CV0, VSS
2nd pin CV1, V1
3rd pin CV2, V4
4th pin CV3, V5
Charging pin CHG
Discharge pin DSG
Charge enable pin CTRC
Discharge enable pin CTRD
Output pin OUT

Claims (14)

As a battery protection circuit,
The battery protection circuit is electrically connected between a battery cell unit and an external port to form a power supply circuit, and the battery protection circuit includes a first protection unit, a second protection unit, and a detection switch unit,
The first protection unit is electrically connected between the battery cell unit and the second protection unit,
The detection switch unit is installed at a preset position of the battery cell unit, the detection switch unit is electrically connected to the second protection unit,
When the detection switch unit is triggered to be turned on and the first protection unit turns on the power supply circuit, the battery protection circuit is configured to protect the battery cell unit by controlling the second protection unit. The method of claim 1,
The second protection unit includes a fuse, a first resistor, and a first switch, a first terminal of the fuse is electrically connected to a positive electrode of the battery cell unit, and a second terminal of the fuse applies the first resistance. Is electrically connected to the second terminal of the first switch, the third terminal of the fuse is electrically connected to the positive electrode of the external port, and the first terminal of the first switch is electrically connected to the sensing switch unit, And a second terminal of the first switch is grounded, and a third terminal of the first switch is electrically connected to a second terminal of the fuse. The method of claim 2,
The detection switch unit is a temperature switch, and when the temperature switch detects that the temperature of the battery cell unit exceeds a preset temperature, the temperature switch is triggered to be turned on, and the first switch is triggered to be turned on. Heating the first resistor and breaking the fuse to protect the battery cell unit. The method of claim 2,
The sensing switch unit is a micro switch, and when the battery cell unit is compressed by thermal expansion, the micro switch is triggered to be turned on, thereby triggering the first switch to be turned on to heat the first resistor, and open the fuse. Cut off, the battery protection circuit, characterized in that to protect the battery cell unit. The method of claim 1,
The battery protection circuit further comprises a third protection unit, wherein the third protection unit is electrically connected between the battery cell unit and the second protection unit. The method of claim 5,
When the detection switch unit is triggered to be turned on, the first protection unit turns the power supply circuit on, and when the third protection unit does not trigger the second protection unit, the second protection unit is turned on. Controlled to protect the battery cell unit, characterized in that the battery protection circuit. A battery management system comprising a battery protection circuit according to any one of claims 1 to 6. The method of claim 7,
Wherein the battery management system controls the battery cell unit to protect the battery cell unit by triggering the second protection unit when the detection switch unit is turned on when the battery cell unit is discharged with a preset current Management system. The method of claim 8,
The second protection unit includes a fuse, and a difference between the rated current of the fuse and the preset current is less than or equal to a current threshold. A battery device comprising a battery cell unit,
The battery device further comprises a battery protection circuit according to any one of claims 1 to 6, wherein the battery protection circuit is used to protect the battery cell unit. A method of controlling a battery device, wherein the battery device includes a battery cell unit and a battery protection circuit electrically connected to the battery cell unit, and the battery protection circuit is electrically connected between the battery cell unit and an external port to supply power. Forming a circuit, the battery protection circuit comprising a first protection unit, a second protection unit and a detection switch unit, the method comprising:
And when the detection switch unit is triggered to be turned on and the first protection unit turns the power supply circuit on, controlling the second protection unit to protect the battery cell unit. How to control the battery device. The method of claim 11,
The battery protection circuit further comprises a third protection unit electrically connected between the battery cell unit and the second protection unit, the method comprising:
When the detection switch unit is triggered to be turned on, the first protection unit turns the power supply circuit on, and the third protection unit does not trigger the second protection unit, the second protection unit Controlling the battery device further comprising the step of protecting the battery cell unit by controlling the control method. The method of claim 11,
The battery device includes a battery management system, and the control method of the battery device,
The battery management system controls the battery cell unit to protect the battery cell unit by controlling the second protection unit when the detection switch unit is triggered to be turned on when the battery cell unit is discharged with a preset current. How to control the battery device. The method of claim 13,
The second protection unit includes a fuse, and a difference between the rated current of the fuse and the preset current is less than or equal to a current threshold.

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