JP7377860B2 - Battery protection circuit, battery management system, battery device and its control method - Google Patents

Description

<Cross reference of related applications>
This application has the priority of a Chinese patent application filed on June 17, 2020 with application number 201055943.6 and the title of the invention is "Battery protection circuit, battery management system, battery device, and control method thereof" , the entire contents of which are incorporated into this application by reference.
The present application relates to the field of battery technology, and particularly relates to a battery protection circuit, a battery management system equipped with the same, a battery device, and a control method thereof.

Lithium-ion batteries are already widely used as an important energy source, play a vital role in fields such as electronic communications and transportation, and have a wide range of application prospects. The safety of lithium-ion batteries is also an issue that cannot be ignored.

Lithium-ion batteries are generally safe when used normally, but can become a potential hazard in the event of internal or mechanical failure. For example, if the battery is misused, such as overcharging, extrusion, high temperature or short circuit, it may overheat, emit smoke, and explode. In the prior art, protection chips in lithium-ion batteries monitor the charging and discharging processes and intervene if the process could risk exceeding the battery's safe operating range. However, once the protection chip of a lithium-ion battery expires, a risk alarm cannot be issued for the battery.
<Prior art documents>
<Patent Document> Patent Document 1: China Patent Application Publication No. 107342600

In view of these problems, there is a need for a battery protection circuit that can protect the electric core unit, a battery management system, a battery device, and a control method thereof that include this battery protection circuit.

A battery protection circuit according to an embodiment of the present application is electrically connected between an electric core unit and an external port to form a power supply circuit, and includes a first protection unit, a second protection unit, and a sensing a switch unit, the first protection unit being electrically connected between the electrical core unit and the second protection unit. The sensing switch unit is disposed at a predetermined position of the electrical core unit and electrically connected to the second protection unit. When the sensing switch unit is triggered to turn on and the first protection unit conducts the power supply circuit, controlling the second protection unit to protect the electrical core unit.

According to some aspects of the present application, the second protection unit includes a fuse, a first resistor, and a first switch, and a first end of the fuse is connected to the positive terminal of the electrical core unit. A second end of the fuse is connected to a second end of the first switch via the first resistor, and a third end of the fuse is connected to a positive terminal of the external port. A first end of the first switch is electrically connected to the sensing switch unit, a second end of the first switch is grounded, and a third end of the first switch is connected to the second end of the fuse. electrically connected to.

According to some aspects of the present application, the sensing switch unit is a temperature switch, and when detecting that the temperature of the electrical core unit exceeds a preset temperature, the temperature switch is triggered to turn on. As a result, the first switch is turned on to heat the first resistor, and the fuse is blown to protect the electrical core unit.

According to some aspects of the present application, the sensing switch unit is a microswitch, and when the electrical core unit is pushed out due to thermal expansion, the microswitch is turned on, thereby turning on the first switch. Triggered on to heat the first resistor and blow the fuse to protect the electrical core unit.

According to some aspects of the present application, the battery protection circuit further includes a third protection unit electrically connected between the electrical core unit and the second protection unit.

According to some aspects of the present application, the sensing switch unit is triggered to turn on, the first protection unit conducts the power supply circuit, and the third protection unit conducts the power supply circuit. The second protection unit is controlled to protect the electrical core unit when the protection unit is not triggered.

One embodiment of the present application discloses a battery management system including the battery protection circuit as described above.

According to some aspects of the present application, the battery management system controls the second protection when the sensing switch unit is turned on when controlling the electrical core unit to discharge at a preset current. Trigger the unit to protect the electrical core unit.

According to some aspects of the present application, the second protection unit includes a fuse, and the difference between the rated current of the fuse and the preset current is less than or equal to a current threshold. A battery device according to an embodiment of the present application includes an electric core unit and a battery protection circuit as described above, and the battery protection circuit is used to protect the electric core unit.

An embodiment of the present application discloses a method of controlling a battery device. The battery device includes an electric core unit and a battery protection circuit electrically connected to the electric core unit, and the battery protection circuit is electrically connected between the electric core unit and an external port to supply power. forming a circuit, the battery protection circuit including a first protection unit, a second protection unit and a sensing switch unit, the method triggering the sensing switch unit to turn on; and controlling the second protection unit to protect the electrical core unit when the first protection unit conducts the power supply circuit.

According to some embodiments of the present application, the battery protection circuit further comprises a third protection unit electrically connected between the electrical core unit and the second protection unit, and the method includes: , when the sensing switch unit is triggered to turn on, the first protection unit conducts the power supply circuit, and the third protection unit does not trigger the second protection unit, the electricity The method further includes controlling the second protection unit to protect the core unit.

According to some embodiments of the present application, the battery device includes a battery management system, and the method includes:
The battery management system controls the electrical core unit to protect the electrical core unit when the sensing switch unit is triggered to turn on when controlling the electrical core unit to discharge with a preset current. and controlling the second protection unit.

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

A battery protection circuit and a battery management system equipped with the battery protection circuit disclosed by the present invention include providing a sensing switch unit electrically connected to the second protection unit at a predetermined position of the electric core unit. , when the first protection unit does not trigger the second protection unit and the sensing switch unit is triggered to turn on, the second protection unit protects the electrical core unit. control. The present invention effectively avoids accidents in which the electric core unit catches fire and explodes by overcharging, overdischarging, or discharging at a high magnification with a current close to the rated current of the fuse when the battery management system fails at one point. I can do it. The battery protection circuit provided by the present application has advantages such as high safety, wide range of applications, and low cost.

FIG. 1 is a block diagram of a battery device according to a first preferred embodiment of the present application. FIG. 2 is a block diagram of a battery device according to a second preferred embodiment of the present application. 2 is a circuit diagram of a first embodiment of a battery protection circuit in the battery management system of FIG. 1. FIG. 2 is a circuit diagram of a second embodiment of a battery protection circuit in the battery management system of FIG. 1. FIG. 1 is a flowchart of a method for controlling a battery device according to a first preferred embodiment of the present application.

The following specific embodiments further explain the invention in conjunction with the above-described drawings.

Hereinafter, the technical solution in the embodiments of the present application will be clearly and comprehensively explained with reference to the drawings in the embodiments of the present application. However, the embodiments described here are only some of the embodiments of the present application, not all the embodiments. It is clear that there is no such thing.

In addition, in the description of the embodiments of this application, the term "connection" should be broadly understood unless there is a particularly clear provision or limitation, and for example, it may be a fixed connection or a removable connection. It may be a connection or an integral connection. Further, the connection may be mechanical, electrical, or mutually communicable. Further, they may be connected directly or indirectly via an intermediate medium. Further, it may be an internal communication between two elements or an interaction relationship between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application depending on the specific situation.

The terms "first," "second," "third," etc. in the specification and claims of the present application and the above drawings are not intended to explain a specific order, but to distinguish different objects. It is a term for Also, the term "comprising" and any variations thereof is intended to be inclusive and not exclusive.

As shown in FIG. 1, FIG. 1 is a block diagram of a battery device according to a preferred embodiment of the present application. The battery device 100 includes an electric core unit 200 and a battery protection circuit 300 electrically connected to the electric core unit 200. The battery protection circuit 300 is included in a battery management system 400 and protects the electrical core unit 200 when the battery management system 400 controls charging and discharging of the electrical core unit 200. The battery protection circuit 300 is electrically connected between the electric core unit 200 and the external port 500 to form a power supply circuit. The battery protection circuit 300 controls conduction/cutoff of the power supply circuit to protect the electric core unit 200 when the battery management system 400 controls charging and discharging of the electric core unit 200.

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

Specifically, in the embodiment of the present application, the first protection unit 30 is electrically connected between the electrical core unit 200 and the second protection unit 31. The sensing switch unit 32 is disposed at a predetermined position of the electric core unit 200, and the sensing switch unit 32 is electrically connected to the second protection unit 31. In normal use, the sensing switch unit 32 is in an off state. triggering the second protection unit 31 to protect the electrical core unit 200 when the first protection unit 30 does not interrupt the power supply circuit and the sensing switch unit 32 is turned on; I can do it. Note that the predetermined position can be set depending on the difference in the sensing switch unit 32. For example, if the sensing switch unit 32 is a temperature switch, the predetermined position is a location where the highest temperature point on the surface of the electrical core unit 200 is located. When the sensing switch unit 32 is a microswitch, the predetermined position is a position on the surface of the electric core unit 200 that is most likely to expand. Note that the location where the highest temperature point or the most easily expanded point of the electrical core unit 200 is located is already determined when the electrical core unit 200 is shipped. For example, by performing thermal simulation and testing based on the battery system, chemical composition, and structure of the electric core unit 200, the position of the highest temperature point or the point where the electric core unit 200 is most likely to expand in the battery system can be determined. can get. Electrical core units 200 of different battery systems do not have the same location of the point with the highest surface temperature or the point where it is most likely to expand. In one embodiment, the first protection unit 30 includes a plurality of first protection chips for protecting each core in the electrical core unit 200.

In one embodiment, as shown in 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-end fuse. A first end of the fuse 310 is connected to the positive electrode of the electrical core unit 200, and a second end of the fuse 310 is connected to the second end of the first switch Q1 via the first resistor R1. The third end of the fuse 310 is connected to the positive terminal of the external port 500. A first end of the first switch Q1 is electrically connected to the sensing switch unit 32, a third end of the first switch Q1 is electrically connected to a second end of the fuse 310, and a third end of the first switch Q1 is electrically connected to the second end of the fuse 310. The second end of the switch Q1 of No. 1 is grounded. The first switch Q1 may be an N-type field effect transistor. A first end, a second end, and a third end 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 detects the temperature or expansion width of the electric core unit 200 or the pressure when pressed. For example, the sensing switch unit 32 is a temperature switch that can detect the temperature at a predetermined position of the electric core unit 200 and compare the detected temperature with a preset temperature. If the sensed temperature is greater than the preset temperature, the temperature switch is triggered to turn on, causing the first switch Q1 to turn on and heat the first resistor R1. Further, the fuse 310 is blown to protect the electrical core unit 200.

In another embodiment, the sensing switch unit 32 is a microswitch. When the electric core unit 200 is heated, it expands, and when the electric core unit 200 is pushed out after expanding (for example, when a case is pressed against the electric core unit 200), the microswitch is triggered to turn on. As a result, the first switch Q1 is turned on to heat the first resistor R1, and the fuse 310 is blown to protect the electrical core unit 200.

Note that the sensing switch unit 32 may be replaced with a component having similar characteristics to another temperature switch or a mechanical component. For example, the sensing switch unit 32 may be a displacement sensing switch for sensing the width of thermal expansion of the electrical core unit 200. When the detected amplitude exceeds a preset width, the displacement sensing switch is triggered to turn on, which turns on the first switch Q1 and heats the first resistor R1. , the fuse 310 is blown to protect the electrical core unit 200.

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

In one embodiment, the battery protection circuit 300 further includes a third protection unit 33, as shown in FIG. The third protection unit 33 is electrically connected between the electrical core unit 200 and the second protection unit 31. If the first protection unit 30 does not interrupt the power supply circuit and the third protection unit 33 does not trigger the second protection unit 31 and the sensing switch unit 32 is turned on; , the second protection unit 31 is triggered to protect the electrical core unit 200. The third protection unit 33 includes a plurality of second protection chips for doubly protecting each electrical core unit in the electrical core unit 200 in combination with the first protection unit 30 .

In one embodiment, when the first protection unit 30 expires and the third protection unit 33 is triggered, the second protection unit 31 is activated to protect the electrical core unit 200. A signal may be output to the second protection unit 31. When the first protection unit 30 expires and the third protection unit 33 also fails, the sensing switch unit 32 triggers the second protection unit 31 to switch off the electrical core unit 200. can be protected.

Note that the first protection unit 30 is invalidated when the parameter of the electric core unit 200 is greater than or equal to a first preset parameter, the first protection unit 30 cuts off the power supply circuit. (for example, turning off the second switch Q2 or the third switch Q3). The parameters of the electrical core unit 200 may be current, voltage or temperature. If the parameter is temperature, it can be seen that the set temperature corresponding to the first protection unit 30 is lower than the temperature when the sensing switch unit 32 is triggered. For example, the first set temperature corresponding to the first protection unit 30 is 50° C., and the temperature when the sensing switch unit 32 is triggered is the highest temperature that the electrical core unit 200 can withstand (e.g. 70°C).

Note that the third protection unit 33 expires when the parameter of the electrical core unit 200 is greater than or equal to the second preset parameter, the first protection unit 30 This means that the protection unit 31 of the device is not triggered. The second preset parameter is larger than the first preset parameter and smaller than the threshold value when the sensing switch unit 32 is triggered.

For example, if the voltage of the electrical core unit 200 exceeds a preset voltage and reaches a voltage threshold that triggers the first protection unit 30, the first protection unit 30 is triggered to Unit 200 can be protected.

If the voltage of the electrical core unit 200 exceeds a preset voltage and reaches a voltage threshold that triggers the first protection unit 30, but the first protection unit 30 expires, the electrical core unit 200 Check whether the voltage has reached the voltage threshold to trigger the third protection unit 33, and if the voltage of the electric core unit 200 has reached the voltage threshold to trigger the third protection unit 33; The third protection unit 33 may be triggered to output a driving signal to the second protection unit 31 to control the second protection unit 31 to protect the electrical core unit 200. .

If the voltage of the electrical core unit 200 exceeds a preset voltage and reaches a voltage threshold that triggers the first protection unit 30, but the first protection unit 30 expires, the electrical core unit 200 checking whether the voltage has reached the voltage threshold to trigger the third protection unit 33; the voltage of the electrical core unit 200 has reached the voltage threshold to trigger the third protection unit 33; When the third protection unit 33 expires, the sensing switch unit 32 is triggered to turn on and then outputs a driving signal to the second protection unit 31 so that the second protection unit 31 The electrical core unit 200 is controlled to be protected.

As shown in FIG. 3, FIG. 3 is a circuit diagram of a battery protection circuit 300 according to the first embodiment of the present application.

In this embodiment, the first protection unit 30 will be explained as an example including three first protection chips. Four electrical cores are connected to each first protection chip. 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, a third resistor R3, . . . a seventh resistor. resistor R7. The electric core unit 200 includes a first electric core B1, a second electric core B2, . . . a twelfth electric core B12. In one embodiment, the first protection chip IC1 is connected to the first to fourth electrical cores B1 to B4 to protect the first to fourth electrical cores B1 to B4. For example, one end of the second resistor R2 is connected to the positive electrode of the first electric core B1, and the other end of the second resistor R2 is connected to the negative electrode of the first electric core B1. One end of the second resistor R2 is further connected to the first pin CV0 of the first protection chip IC1, and the other end of the second resistor R2 is further connected to the second pin CV0 of the first protection chip IC1. is connected to pin CV1 of One end of the fifth resistor R5 is connected to the positive electrode of the fourth electric core B4, and the other end of the fifth resistor R5 is connected to the negative electrode of the fourth electric core 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 connected to the fourth pin CV4 of the first protection chip IC1. is also connected.

By analogy, the first protection chip IC2 connects the fifth electric core B5 to the eighth electric core B8, and connects the fifth electric core B5 to the eighth electric core B8. protect The first protection chip IC3 connects the ninth electric core B9 to the twelfth electric core B12 and protects the ninth electric core B9 to the twelfth electric core B12. The specific connection method is similar to the connection method in which the first protection chip IC1 connects the first electric core B1 to the fourth electric core B4, and detailed explanation will be omitted here. Note that the first protection unit 30 may include N first protection chips, and the present application does not limit the number of first protection chips.

The first protection unit 30 further includes a second switch Q2, a third switch Q3, and a resistor R0. The resistor R0 is for collecting the current of the power supply circuit, that is, the current flowing to the electric core unit 200. In this embodiment, one end of the resistor R0 is connected to the negative electrode of the first electric core B1, and the other end of the resistor R0 is connected to the second switch Q2. One end of the resistor R0 is further connected to the SRP pin of the first protection chip IC1, and the other end of the resistor R0 is further connected to the SRN pin of the first protection chip IC1. . By detecting the voltage of the resistor R0, the first protection chip IC1 can calculate the current flowing through the electric core unit 200 from the voltage and the resistance value of the resistor R0.

A first end of the second switch Q2 is connected to the discharge pin DSG of the first protection chip IC1, a second end of the second switch Q2 is connected to the resistor R0, and the second end of the second switch Q2 is connected to the discharge pin DSG of the first protection chip IC1. The third end of the switch Q2 is connected to the second end of the third switch Q3, and the first end of the third switch Q3 is connected to the charging pin CHG of the first protection chip IC1. A third end of the third switch Q3 is connected to a third end of the second switch Q2, and a second end of the third switch Q3 is connected to the negative terminal of the external port 500.

The second switch Q2 and the third switch Q3 may be N-type field effect transistors. A first end, a second end, and a third end 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 connected in cascade to control the second switch Q2 and the third switch Q3. This makes it possible to control conduction/cutoff of the power supply circuit. Specifically, the charging pin CHG of the first protection chip IC3 is connected to the charging enable pin CTRC of the first protection chip IC2, and the discharge pin DSG of the first protection chip IC3 is connected to the charging enable pin CTRC of the first protection chip IC2. The charge pin CHG of the first protection chip IC2 is connected to the discharge enable pin CTRD of the chip IC2, and the charge pin CHG of the first protection chip IC2 is connected to the charge enable pin CTRC of the first protection chip IC2. is connected to the discharge enable pin CTRD of the first protection chip IC1, and the charging pin CHG of the first protection chip IC1 is connected to the third switch Q3, and the charge pin CHG of the first protection chip IC1 is connected to the discharge enable pin CTRD of the first protection chip IC1. DSG is connected to said second switch Q2. When any one of the first protection chip IC1 to first protection chip IC3 detects that an overcharge or overdischarge situation has occurred in the electric core unit 200, the charge enable pin CTRC or the discharge enable pin CTRD is activated. The purpose of protecting the electrical core unit 200 is realized by outputting a driving signal to the charging pin CHG or the discharging pin DSG, and controlling the second switch Q2 or the third switch Q3 to be turned off.

In normal use, the sensing switch unit 32 is in the off state, the second end of the fuse 310 in the second protection unit 31 is connected to the second end of the first switch Q1, and the power supply circuit is in a normal state. It operates. When the first protection unit 30 in the power supply circuit expires, the first protection unit 30 does not turn off the second switch Q2 or the third switch Q3 in order to cut off the power supply circuit. When an abnormality occurs in the electric core unit 200 due to overvoltage or undervoltage (for example, the temperature of the electric core rises to a threshold value, the electric core thermally expands, or the electric core is pushed out due to heat), Trigger the sensing switch unit 32 to turn on. This triggers the first switch Q1 to turn on, heating the first resistor and blowing the fuse, cutting off the power supply circuit and preventing continued charging or discharging. to prevent the electric core unit 200 from catching fire or exploding.

In one embodiment, when the battery management system 400 controls the electrical core unit 200 to discharge with a preset current (eg, continuously discharge with a current of 3C to 6C), the fuse 310 cannot blow. That is, the battery management system 400 controls the electrical core unit 200 to continuously discharge at a rated current close to the fuse 310. Continuous high-magnification discharge may cause an abnormality in the electrical core unit 200 (e.g., the temperature of the electrical core rises to a temperature threshold that can be tolerated by the sensing switch unit, or the width of thermal expansion of the electrical core exceeds the width threshold). (or the pressure exerted by the heat of the electric core is greater than the pressure threshold), the sensing switch unit 32 is triggered to turn on. This triggers the first switch Q1 to turn on, heats the first resistor R1, blows the fuse 310, and causes the electric core unit 200 to continue discharging, causing ignition or explosion. Avoid dangerous accidents such as 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.

As shown in FIG. 4, FIG. 4 is a circuit diagram of a battery protection circuit 300 according to a second embodiment of the present application.

The battery protection circuit 300 of this embodiment differs from the battery protection circuit 300 of the first embodiment in the following points.

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 electrical core unit 200 and the second protection unit 31. The third protection unit 33 includes a plurality of second protection chips for doubly protecting each electrical core unit of the electrical core unit 200 in combination with the first protection unit 30 .

For example, an example will be described in which the third protection unit 33 includes three second protection chips. Four electrical cores are connected to each second protection chip. The third protection unit 33 includes a second protection chip IC1', a second protection chip IC2', a second protection chip IC3', a resistor R1', a resistor R2'..., and a resistor R7'. . In one embodiment, the second protection chip IC1' connects the first electric core B1 to fourth electric core B4, and connects the first electric core B1 to fourth electric core B4. Next protect. For example, the first pin VSS of the second protection chip IC1' is connected to the negative electrode of the first electric core B1, and the second pin V1 of the second protection chip IC1' is connected to the first electric core B1. After the third pin V4 and the fourth pin V5 of the second protection chip IC1' are connected to the positive terminal of the second protection chip IC1', the fourth electric Connected to the positive electrode of core B4.

By analogy, the second protection chip IC2' connects the fifth electric core B5 to the eighth electric core B8, and connects the fifth electric core B5 to the eighth electric core B8. Protect B8. The second protection chip IC3' connects the ninth electric core B9 to the twelfth electric core B12 and protects the ninth electric core B9 to the twelfth electric core B12. The specific connection method is similar to the connection method in which the second protection chip IC1' connects the first electric core B1 to the fourth electric core B4, so a detailed explanation will be omitted here. Note that the third protection unit 33 may include N second protection chips, and the present application does not limit the number of second protection chips.

In this embodiment, after 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' are connected, It is connected to a first end (eg, F1-C) of the first switch Q1. When the first protection unit 30 (i.e., the first protection chips IC1 to IC3) expires, the electrical core unit 200 is overcharged or overdischarged, and the first A drive signal is output to the switch Q1, and the first switch Q1 is driven to turn on. As a result, the first resistor R1 is heated and the fuse 310 is blown, thereby preventing accidents such as fire or explosion due to continuous charging or discharging of the electric core unit 200.

In normal use, the sensing switch unit 32 is in an off state, and the power supply circuit operates normally. On the other hand, when both the first protection unit 30 and the third protection unit 33 fail, that is, the second switch Q2 or the third If the switch Q3 is not turned off and the third protection unit 33 does not trigger the second protection unit 31, the electric core unit 200 will malfunction due to overvoltage or undervoltage. (For example, the temperature of the electrical core rises to a temperature threshold that can be withstood by the sensing switch unit, or the width of the thermal expansion of the electrical core exceeds the width threshold, or the pressure exerted by the heat of the electrical core is greater than the pressure threshold) If so, the sensing switch unit 32 is triggered to turn on. This triggers the first switch Q1 to turn on, heats the first resistor, and blows the fuse to protect the electrical core unit 200 and prevent fire or explosion. prevent accidents.

Similarly, when the battery management system 400 controls the electric core unit 200 to discharge at a preset current, the battery continues to discharge at a current of 3C to 6C, for example, and the fuse cannot blow. That is, the battery management system 400 continuously discharges at a current close to the rated current of the fuse 310, and the difference between the rated current of the fuse 310 and the preset current is smaller than or equal to the current threshold value. . Continuous high-magnification discharge may cause an abnormality in the electrical core unit 200 (e.g., the temperature of the electrical core rises to a temperature threshold that can be tolerated by the sensing switch unit, or the width of thermal expansion of the electrical core exceeds the width threshold). (or the pressure exerted by the heat of the electric core is greater than the pressure threshold), the sensing switch unit 32 is triggered to turn on. As a result, the first switch Q1 is turned on and heats the first resistor R1, the fuse 310 is blown, and the electrical core unit 200 is continuously discharged, resulting in a dangerous accident such as ignition or explosion. can be avoided.

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 application. The method for controlling the battery device may include the following steps.

In step S1, when the sensing switch unit is triggered to turn on and the first protection unit conducts the power supply circuit, controlling the second protection unit to protect the electric core unit; do.

In this embodiment, the battery device 100 includes an electric core unit 200 and a battery protection circuit 300 electrically connected to the electric core unit 200. It is electrically connected to the attached port 500 to form a power supply circuit. The battery protection circuit 300 includes a first protection unit 30, a second protection unit 31, and a sensing switch unit 32.

In normal use, the sensing switch unit 32 is in the off state, the second end of the fuse 310 in the second protection unit 31 is connected to the second end of the first switch Q1, and the power supply circuit is normally operated. Operate. When the first protection unit 30 in the power supply circuit expires, the first protection unit 30 does not turn off the second switch Q2 or the third switch Q3 to cut off the power supply circuit. The electric core unit 200 is activated when an abnormality occurs due to overvoltage or undervoltage (for example, the temperature of the electric core rises to a threshold value, the electric core thermally expands, or the electric core unit is pushed out by heat), and a sensing switch is activated. Unit 32 is triggered to turn on and control the second protection unit to protect the electrical core unit. That is, the first switch Q1 in the second protection unit is triggered to turn on, heating the first resistor, blowing the fuse, cutting off the power supply circuit, and continuously charging or discharging. This prevents the electric core unit 200 from igniting or exploding.

In step S2, if the sensing switch unit 32 is triggered to turn on, the first protection unit 30 has not cut off the power supply circuit, and the third protection unit 33 has not cut off the power supply circuit; If the protection unit 31 is not triggered, the second protection unit 31 is controlled to protect the electric core unit.

In normal use, the sensing switch unit 32 is in an off state, and the power supply circuit operates normally. On the other hand, when both the first protection unit 30 and the third protection unit 33 fail, that is, the second switch Q2 or the third If the switch Q3 is not turned off and the third protection unit 33 does not trigger the second protection unit 31, the electric core unit 200 will malfunction due to overvoltage or undervoltage. (For example, the temperature of the electrical core rises to a temperature threshold that can be withstood by the sensing switch unit, or the width of the thermal expansion of the electrical core exceeds the width threshold, or the pressure exerted by the heat of the electrical core is greater than the pressure threshold) If so, the sensing switch unit 32 is triggered to turn on. This triggers the first switch Q1 to turn on, heats the first resistor, and blows the fuse 310 to protect the electrical core unit 200 and prevent fire or explosion. prevent accidents.

In one embodiment, the method comprises: when the battery management system 400 controls the electrical core unit 200 to discharge with a preset current, when the sensing switch unit 32 is turned on; The method further includes triggering protection of the electric core knit by the second protection unit 31.

In one embodiment, when the battery management system 400 controls the electrical core unit 200 to discharge with a preset current (eg, continuously discharge with a current of 3C to 6C), the fuse 310 cannot blow. That is, the battery management system 400 controls the electrical core unit 200 to continuously discharge at a rated current close to the fuse 310. Continuous high-magnification discharge may cause an abnormality in the electrical core unit 200 (e.g., the temperature of the electrical core rises to a temperature threshold that can be tolerated by the sensing switch unit, or the width of thermal expansion of the electrical core exceeds the width threshold). (or the pressure exerted by the heat of the electric core is greater than the pressure threshold), the sensing switch unit 32 is triggered to turn on. This triggers the first switch Q1 to turn on, heats the first resistor R1, blows the fuse 310, and causes the electric core unit 200 to continue discharging, causing ignition or explosion. Avoid dangerous accidents such as 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.

The battery protection circuit 300 according to the embodiment described above and the battery management system 400 including the battery protection circuit 300 include a battery protection circuit 300 that is electrically connected to the second protection unit 31 at a predetermined position of the electric core unit 200. By providing a sensing switch unit 32, the first protection unit 30 does not trigger the second protection unit 31, and when the sensing switch unit 32 is triggered and turned on, the second protection unit 31 to protect the electrical core unit 200. The present invention effectively prevents an accident in which the electric core unit 200 ignites and explodes due to overcharging, overdischarging, or discharging at a high magnification with a current close to the rated current of the fuse 310 when the battery management system 400 fails at one point. can be avoided. The battery protection circuit 300 provided by the present application has advantages such as high safety, wide range of applications, and low cost.

Those skilled in the art will understand that the above embodiments are only used to explain the technical proposal of the present application, and are not intended to limit the present application, and may appropriately modify the above embodiments as long as it is within the substantial spirit of the present application. It should be understood that those obtained by or equivalent substitution also fall within the protection scope of the present application.

100 battery device 200 electric core unit 300 battery protection circuit 400 battery management system 500 external port 30 first protection unit 31 second protection unit 32 sensing switch unit 33 third protection unit R1 first resistor R0, R1'~R7' Resistor 310 Fuse Q1 First switch Q2 Second switch Q3 Third switch IC1, IC2, IC3 First protection chip IC1', IC2', IC3' Second protection chip R2 to R7 Second Resistance to 7th resistance B1 to B12 1st to 12th electrical core CV0, VSS 1st pin CV1, V1 2nd pin CV2, V4 3rd pin CV3, V5 4th pin CHG Charging Pin DSG Discharge pin CTRC Charge enable pin CTRD Discharge enable pin ОUT Output pin

Claims (14)

A battery protection circuit,
electrically connected between the electric core unit and the external port to form a power supply circuit, and comprising a first protection unit, a second protection unit, and a sensing switch;
the first protection unit is electrically connected between the electrical core unit and the second protection unit;
The sensing switch is disposed at a predetermined position of the electric core unit and electrically connected to the second protection unit,
When an abnormality occurs in the electric core unit, the sensing switch is triggered to turn on, and when the first protection unit conducts the power supply circuit, the first protection unit protects the electric core unit. controlling a second protection unit;
A battery protection circuit, wherein the second protection unit includes a fuse, a first resistor, and a first switch. A first end of the fuse is connected to the positive terminal of the electrical core unit, a second end of the fuse is connected to a second end of the first switch via the first resistor, and a third end of the fuse is connected to the positive terminal of the electrical core unit. one end of the first switch is connected to the positive terminal of the external port, a first end of the first switch is electrically connected to the sensing switch, a second end of the first switch is grounded, and the second end of the first switch is electrically connected to the sensing switch. The battery protection circuit according to claim 1, wherein a third end of the fuse is electrically connected to the second end of the fuse. The sensing switch is a temperature switch, and when detecting that the temperature of the electrical core unit exceeds a preset temperature, the temperature switch is triggered to turn on, thereby causing the first switch to 3. The battery protection circuit according to claim 2, wherein: is turned on to heat the first resistor, and the fuse is blown to protect the electric core unit. The sensing switch is a microswitch, and when the electrical core unit is pushed out due to thermal expansion, the microswitch is turned on, which triggers the first switch to be turned on, and the first switch is turned on. 3. The battery protection circuit according to claim 2, wherein one resistor is heated and the fuse is blown to protect the electric core unit. The battery protection circuit according to claim 1, further comprising a third protection unit electrically connected between the electric core unit and the second protection unit. When the sensing switch is triggered to turn on, the first protection unit conducts the power supply circuit, and the third protection unit does not trigger the second protection unit, the electrical core The battery protection circuit according to claim 5, wherein the second protection unit is controlled to protect the unit. A battery management system comprising the battery protection circuit according to any one of claims 1 to 6. When the battery management system controls the electric core unit to discharge at a preset current, when the sensing switch is turned on, the battery management system triggers the second protection unit to protect the electric core unit. The battery management system according to claim 7, characterized in that: The battery management system according to claim 8, wherein the second protection unit includes a fuse, and a difference between the rated current of the fuse and the preset current is smaller than or equal to a current threshold. . A battery device comprising an electric core unit,
A battery device further comprising the battery protection circuit according to any one of claims 1 to 6, wherein the battery protection circuit is used to protect the electric core unit. . A method for controlling a battery device, the battery device including an electric core unit and a battery protection circuit electrically connected to the electric core unit,
The battery protection circuit is electrically connected between the electric core unit and the external port to form a power supply circuit, and the battery protection circuit includes a first protection unit, a second protection unit and a sensing switch. including;
The control method is configured to trigger the sensing switch to turn on when an abnormality occurs in the electrical core unit, and to protect the electrical core unit when the first protection unit conducts the power supply circuit. controlling the second protection unit to
A method for controlling a battery device, wherein the second protection unit includes a fuse, a first resistor, and a first switch. The battery protection circuit further includes a third protection unit electrically connected between the electric core unit and the second protection unit, and the control method includes controlling the sensing switch to turn on. When triggered, the first protection unit conducts the power supply circuit, and the third protection unit does not trigger the second protection unit, the second protection unit is configured to protect the electrical core unit. The method of controlling a battery device according to claim 11, further comprising controlling a protection unit. The battery device includes a battery management system, and the battery management system is configured to turn on the sensing switch when controlling the electric core unit to discharge at a preset current. The method of controlling a battery device according to claim 11, further comprising controlling the second protection unit to protect the electric core unit when triggered. 14. The method of controlling a battery device according to claim 13, wherein a difference between the rated current of the fuse and the preset current is smaller than or equal to a current threshold value.