TWI820959B - Circuit and method for detecting battery thermal-runaway events - Google Patents

Abstract

This disclosure provides a circuit for detecting battery thermal-runaway events during , which is applied to a battery module, and configured inside the battery module. The battery module includes at least one battery cell. The circuit includes a battery management system having a microcontroller, and a fan pack. When the battery module is not used, the microcontroller will be set to operate in a power-off mode by the battery management system such that the microcontroller stops to control the charge and discharge produce and control the rotating of the fan pack. When the fan pack is rotated by a wind pressure, the fan pack in the rotating can form an induced electromotive force and therefore output a start power to the microcontroller to restart the microcontroller. After the microcontroller is restarted, it will sense a temperature of the battery cell via a temperature sensing element to determine whether the battery cell is thermally runaway.

Description

Circuit and method for detecting battery thermal runaway

The present invention relates to a circuit and a method for detecting thermal runaway of a battery, and in particular, to a circuit and a method for detecting thermal runaway of a battery by using a fan set.

The battery cell has the function of storing electric charge. Multiple battery cells are connected in series or parallel to form a battery module, which is used as a power source for electronic devices. For example, a battery module is used as a power source for electric vehicles. A battery management system (Battery Management System, BMS) is usually installed in the battery module. The battery management system is used to manage the charging and discharging operations of the battery module and detect whether there are abnormalities in the battery cells inside the battery module, such as thermal runaway of the battery core.

Continuing, when the battery module is not in use, in order to reduce the power consumption of the battery module, the battery management system is usually in shutdown or sleep mode. The battery management system in shutdown or hibernation mode will not detect battery cell abnormalities. If the battery cell experiences thermal runaway due to collision, short circuit or other unpredictable factors, the battery management system in shutdown or hibernation mode will not be able to know. Therefore, if the thermal runaway of the battery core cannot be known at the first time, it will cause a serious fire.

The object of the present invention is to provide a circuit and method for detecting thermal runaway of a battery, which is applied to a battery module. The battery module includes a metal shell, a plurality of battery cores, and a battery fixed rack and a system circuit board. The system circuit board and the battery holder containing the battery cells will be placed inside the metal case. An air inlet and an air outlet are respectively provided on both sides of the metal shell. The air inlet or the air outlet can also be provided with a fan group. A battery management system and a microcontroller are provided on the system circuit board. When the battery module is in use, the battery management system sets the microcontroller to operate in an operating mode. The battery management system controls the charge and discharge of the battery cells through the microcontroller and controls the fan group to rotate normally at a predetermined speed. When the battery module is not in use, the battery management system will shut down, and before the battery management system is shut down, the microcontroller is set to operate in a shutdown mode, and the microcontroller stops controlling the charge and discharge of the battery cells and stops controlling the rotation of the fan set. . When the battery module is not in use, if the battery core undergoes thermal runaway, the pressure inside the sealed metal case will instantly rise due to the thermally runaway battery core, thereby generating a hot wind pressure inside the metal case, and the fan The group will be driven to rotate by hot wind pressure. After the fan group is driven by the wind pressure to rotate, the rotating fan group will generate an induced electromotive force and output a starting power. When the voltage of the starting power supply is higher than a minimum starting voltage of the microcontroller, the microcontroller will start. After the microcontroller is started, it will sense the temperature of the battery cell through the temperature sensor to determine whether the battery cell is thermally out of control. If the battery cell is sensed to have thermal runaway, the microcontroller will initiate thermal runaway emergency response measures to reduce the harm caused by thermal runaway.

In order to achieve the above objectives, the present invention provides a circuit for detecting thermal runaway of a battery, which is applied to a battery module and is arranged inside the battery module. The battery module includes at least one battery cell. The circuit for detecting thermal runaway of the battery includes: : A microcontroller, when the battery module is not in use, the microcontroller operates in a shutdown mode; a temperature sensor, connected to the microcontroller and the battery cell, the microcontroller senses the temperature of the battery cell through the temperature sensor temperature; and a fan group, connected to the microcontroller. When the fan group is driven by a wind pressure to rotate, the rotating fan group forms an induced electromotive force and outputs a starting power to the microcontroller. to restart the microcontroller; after the microcontroller restarts, it senses the temperature of the battery cell through the temperature sensor to determine whether the battery cell is thermally out of control.

In one embodiment of the present invention, a power supply circuit is further included. The power supply circuit includes a first switch, a second switch, a main battery power supply and an external power supply. The first end of the first switch is connected to the main battery power supply or the external power supply. The control end is connected to the microcontroller, and the second end is connected to the microcontroller; the first end of the second switch is connected to the second end of the first switch, the control end is connected to the microcontroller, and the second end is connected to the fan group; when the battery module When the set is used, the microcontroller operates in an operating mode and controls the first switch and the second switch to be turned on. A power supply provided by the main battery power supply or an external power supply supplies power to the microcontroller and the microcontroller through the first switch and the second switch respectively. Fan group; when the battery module is not in use, the microcontroller operates in the shutdown mode, and before the microcontroller enters the shutdown mode from the operating mode, it controls the first switch and the second switch to disconnect, and the main battery power supply or external power supply stops supplying until Microcontroller and fan set.

In an embodiment of the present invention, when the starting power exceeds a minimum starting voltage of the microcontroller, the microcontroller will be restarted.

In one embodiment of the present invention, when the starting power exceeds a minimum starting voltage of the microcontroller and triggers the microcontroller to restart, the main battery power or the backup battery power will be supplied to the microcontroller so that the microcontroller can stably Detect whether the battery cell is thermally runaway.

In one embodiment of the present invention, when the microcontroller senses the temperature of the battery cell through the temperature sensor and determines that the battery cell has thermal runaway, it sends a thermal runaway notification to an external central control system.

In one embodiment of the present invention, when the microcontroller senses the temperature of the battery core through the temperature sensor and determines that the battery core has thermal runaway, the microcontroller controls the second switch to turn on, and the backup battery power supply or the main battery cell is turned on. The power supply provided by the battery power supply is supplied to the fan group through the second switch. The fan group is activated by the power supply. The microcontroller controls the activated fan group to rotate at a predetermined speed or a high speed.

In one embodiment of the present invention, a fuse is provided between the battery core and a power input and output port. When the microcontroller determines that the battery core has thermally runaway based on the temperature of the battery core sensed by the temperature sensor, the microcontroller outputs a Blowing current to the fuse blows the fuse.

The present invention also provides a method for detecting battery thermal runaway, which is applied to a battery module having at least one battery cell. The method for detecting battery thermal runaway includes: setting a microcontroller to operate in a shutdown state when the battery module is not in use. mode; drive the fan group to rotate through a wind pressure; when the fan group is driven to rotate by the wind pressure, an induced electromotive force is formed to output a starting power to the microcontroller; the microcontroller is restarted with the starting power; and the microcontroller after restarting The controller uses a temperature sensor to sense the temperature of the battery core to determine whether the battery core is thermally runaway.

100:battery module

101:Wind pressure

11:Metal shell

12:Battery core

121:Fuse

122:Power input and output port

13:Battery holder

14:System circuit board

151:Air inlet

152:Air outlet

16:Fan group

160: Start power

161: Diode

20:Battery management system

21:Microcontroller

211: fuse current

212:Notification signal

22:Temperature sensor

30:Power supply circuit

31:First switch

32:Second switch

330:Power supply

331: Main battery power

332:External power supply

333: Backup battery power

50: Automatic fire protection system

FIG. 1 is a top perspective view of a battery module according to an embodiment of the present invention.

FIG. 2 is a circuit schematic diagram of an embodiment of a circuit for detecting battery thermal runaway according to the present invention.

Figure 3 is a flow chart of a method for detecting thermal runaway of a battery according to the present invention.

Please refer to FIGS. 1 and 2 , which are a top perspective view of a battery module according to an embodiment of the present invention and a circuit schematic diagram of an embodiment of a circuit for detecting battery thermal runaway according to the present invention. As shown in FIG. 1 , the battery module 100 of the present invention includes a metal case 11 , a plurality of battery cells 12 , a battery holder 13 and a system circuit board (such as Printed Circuit Board Assembly, PCBA) 14 .

The battery cells 12 are accommodated and fixed in the battery holder 13 and are spaced apart from each other. Furthermore, the system circuit board 14 and the battery holder 13 housing the battery core 12 will be arranged inside the metal case 11 to protect the battery core 12 and the system circuit board 14 through the metal case 11 .

An air inlet 151 and an air outlet 152 are respectively provided on both sides of the metal shell 11 . The air inlet 151 or the air outlet 152 may also be provided with a fan group 16 . The battery holder 13 is disposed between the air inlet 151 and the air outlet 152. The fan group 16 blows air at the air inlet 151 or draws air at the air outlet 152, so that air can circulate inside the metal case 11.

Referring to FIGS. 1 and 2 simultaneously, the battery module 100 further includes a battery management system 20 and a microcontroller 21 , which are disposed on the system circuit board 14 . In the present invention, the microcontroller 21 is an internal chip of the battery management system 20 or a chip independent of the battery management system 20 . The microcontroller 21 is connected to the battery cell 12 and the fan group 16 . When the battery module 100 is used, the microcontroller 21 operates in an operating mode, and the battery management system 20 controls the charge and discharge of the battery cell 12 through the microcontroller 21, for example, by switching the conduction of the power input and output switch of the battery cell 12 or It is disconnected to control whether the battery cell 12 is charging or discharging, and the microcontroller 21 is used to control the fan group 16 to rotate normally at a predetermined speed. When the battery module 100 is not in use (such as during transportation or storage of the battery module 100), in order to reduce the power consumption of the battery module 100, the battery management system 20 will cut off its own system power and shut down. The controller 21 is in a shutdown mode, thereby causing the microcontroller 21 to stop controlling the charge and discharge of the battery cell 12 and stop controlling the rotation of the fan group 16 .

Continuing, when the battery module 100 is not in use, if the battery core 12 undergoes thermal runaway, the internal pressure of the sealed metal case 11 will rise instantaneously due to the thermally runaway battery core 12 to generate a pressure inside the metal case 11 When a hot wind pressure 101 occurs, the fan group 16 will be driven by the hot wind pressure 101 to rotate. fan group After 16 is driven to rotate by the wind pressure 101, the rotating fan group 16 will form an induced electromotive force and output a starting power 160 to the microcontroller 21 through a diode 161. When the starting power supply 160 exceeds a minimum starting voltage of the microcontroller 21, the microcontroller 21 will be started. After being activated, the microcontroller 21 will sense the temperature of the battery cell 12 through a temperature sensor 22 to determine whether the battery cell 12 is thermally runaway. Furthermore, the detailed structure of the fan group 16 and how the induced electromotive force is formed when the fan group 16 rotates are publicly disclosed technologies. For example, please refer to Taiwan Patent No. I350344, I773456B, etc., and will not be described in detail here.

Specifically, the battery module 100 further includes a power supply circuit 30 . The power supply circuit 30 includes a first switch 31 , a second switch 32 , a main battery power supply 331 , an external power supply 332 and a backup battery power supply 333 . The microcontroller 21 is provided in the power supply circuit 30 . The first terminal of the first switch 31 is connected to the main battery power supply 331, the external power supply 332 or the backup battery power supply 333, the control terminal is connected to the microcontroller 21, and the second terminal is connected to the microcontroller 21. The first end of the second switch 32 is connected to the second end of the first switch 31 , the control end is connected to the microcontroller 21 , and the second end is connected to the fan group 16 . The main battery power source 331 is the power provided by the battery cell 12 . The external power supply 332 is an independent power supply with external input. The backup battery power 333 is power provided by an independent battery component inside the battery module 100 .

When the battery module 100 is used, the microcontroller 21 operates in the operating mode and controls the first switch 31 and the second switch 32 to be turned on. A power supply 330 provided by the main battery power source 331 or the external power source 332 passes through the first switch 31 respectively. and the second switch 32 to supply power to the battery management system 20 and the fan group 16 .

When the battery module 100 is not in use, the battery management system 20 will cut off its own system power and shut down. Moreover, before cutting off the system power, the battery management system 20 requires the microcontroller 21 to turn off the first switch 31 and the second switch 32 , and the main battery power supply 331 or the external power supply 332 will stop supplying power to the battery management system 20 and the fan group 16 , the microcontroller 21 enters a shutdown mode. Continue, if the battery module 100 is not During use, the battery core 12 undergoes thermal runaway, and the thermal runaway of the battery core 12 generates hot wind pressure 101 inside the metal casing 11 . The hot wind pressure 101 drives the fan group 16 to rotate. The fan group 16 driven to rotate by the hot wind pressure 101 will form an induced electromotive force and output the starting power 160 to the microcontroller 21 . When the voltage of the startup power supply 160 exceeds a minimum startup voltage of the microcontroller 21 (for example, 1.8V), the microcontroller 21 will be restarted. After the microcontroller 21 is restarted, the first switch 31 is controlled to be turned on, so that the power supply 330 provided by the backup battery power supply 333 or the main battery power supply 331 can supply power to the microcontroller 21 . After receiving the backup battery power 333 or the main battery power 331, the microcontroller 21 can stably sense the temperature of the battery core 12 through the temperature sensor 22 to determine whether the battery core 12 is thermally runaway. For example: when the microcontroller 21 senses through the temperature sensor 22 that the temperature of the battery cell 12 is higher than a threshold, it will know that the battery cell 12 has thermal runaway; or, the microcontroller 21 senses through the temperature sensor 22 When the temperature of the battery core 12 is lower than the threshold value, it will be known that the battery core 12 has not thermally runaway.

In one embodiment of the present invention, if the microcontroller 21 learns that the battery cell 12 has thermally runaway through the temperature sensor 22, the microcontroller 21 enters a thermal runaway processing mode, and the microcontroller 21 further controls the second switch 32 to conduct. This enables the power supply 330 provided by the backup battery power supply 333 or the main battery power supply 331 to supply power to the fan group 16 . Then, the fan group 16 is restarted according to the power supply of the power supply 330 , and the microcontroller 21 controls the fan group 16 to rotate at a predetermined speed or a high speed to quickly take out the high-temperature heat inside the metal case 11 .

Furthermore, the battery cell 12 is connected to a power input and output port 122 through a fuse 121 . In yet another embodiment of the present invention, if the microcontroller 21 learns that the battery cell 12 has thermally runaway through the temperature sensor 22, the microcontroller 21 enters a thermal runaway processing mode. The microcontroller 21 outputs a fusing current 211 to the fuse 121 to blow the fuse 121 so that the battery cell 12 cannot be charged or discharged through the power input and output port 122 .

Alternatively, the microcontroller 21 is connected to an automatic fire protection system 50 . In another embodiment of the present invention, if the microcontroller 21 learns that the battery cell 12 has thermal runaway through the temperature sensor 22, the microcontroller 21 enters a thermal runaway processing mode and will send a notification signal 212 to the automatic fire protection system 50 , to notify the automatic fire protection system 50 of the thermal runaway of the battery cell 12 . Then, after receiving the notification signal 212, the automatic fire protection system 50 will sound an alarm, flash a bright light, or display text, and perform a thermal runaway cooling process on the battery core 12 of the battery module 100 by spraying water or spraying gas.

Or, in another embodiment of the present invention, if the microcontroller 21 learns that the battery cell 12 has thermal runaway through the temperature sensor 22, the microcontroller 21 enters a thermal runaway processing mode and will send a thermal runaway notification to a The external central control system allows the monitor of the central control system to know that the current thermal runaway situation has occurred in the battery module 100 .

Please refer to FIG. 3 , which is a flow chart of a method for detecting thermal runaway of a battery according to the present invention. Referring to Figures 1, 2 and 3 at the same time, first, in step S61, when the battery module 100 is not in use, the microcontroller 21 turns off the first switch 31 and the second switch 32, the main battery power supply 331 or the external power supply. 332 stops supplying power to the battery management system 20 and the fan group 16, the battery management system 20 cuts off its own system power, and the microcontroller 21 enters a shutdown mode from an operating mode.

Then, in step S62, when the battery module 100 is not in use, if the battery core 12 of the battery module 100 thermally runs out of control, hot wind pressure 101 will be generated inside the metal case 11, and the hot wind pressure 101 will drive the fan. Group 16 performs rotation. In step S63, after the fan group 16 is driven by the wind pressure 101 to rotate, the rotating fan group 16 will form an induced electromotive force and output a starting power supply 160.

Step S64, the starting power supply 160 is output to the microcontroller 21; when the starting power supply 160 exceeds a minimum starting voltage of the microcontroller 21, the microcontroller 21 will be restarted; the microcontroller 21 After restarting, the first switch 31 is controlled to be turned on so that the power supply 330 provided by the backup battery power supply 333 or the main battery power supply 331 can supply power to the microcontroller 21 .

In step S65, the restarted microcontroller 21 senses the temperature of the battery core 12 through the temperature sensor 22 to determine whether the battery core 12 is thermally runaway. If the battery cell 12 is sensed to have thermal runaway, the microcontroller 21 enters a thermal runaway processing mode, and the microcontroller 21 will initiate thermal runaway emergency response measures to reduce the harm caused by the thermal runaway of the battery cell 12 .

The above is only an embodiment of the present invention, and is not intended to limit the scope of the present invention. That is, any equal changes and modifications may be made in accordance with the shape, structure, characteristics and spirit described in the patent application scope of the present invention. All should be included in the patentable scope of the present invention.

12:Battery core

121:Fuse

122:Power input and output port

16:Fan group

160: Start power

161: Diode

20:Battery management system

21:Microcontroller

211: fuse current

212:Notification signal

22:Temperature sensor

30:Power supply circuit

31:First switch

32:Second switch

330:Power supply

331: Main battery power

332:External power supply

333: Backup battery power

50: Automatic fire protection system

Claims (10)

A circuit for detecting battery thermal runaway is applied to a battery module and is arranged inside the battery module. The battery module includes at least one battery cell. The circuit for detecting battery thermal runaway includes: a microcontroller, When the battery module is not in use, the microcontroller operates in a shutdown mode; a temperature sensor is connected to the microcontroller and the battery cell, and the microcontroller senses the battery cell through the temperature sensor. temperature; and a fan group connected to the microcontroller. When the fan group is driven by a wind pressure to rotate, the rotating fan group forms an induced electromotive force and outputs a starting power to the microcontroller to restart Start the microcontroller; after restarting, the microcontroller senses the temperature of the battery cell through the temperature sensor to determine whether the battery cell is thermally runaway. The circuit for detecting battery thermal runaway as described in claim 1 further includes a power supply circuit, the power supply circuit includes a first switch, a second switch, a main battery power supply and an external power supply, and the first switch of the first switch The terminal is connected to the main battery power supply or the external power supply, the control terminal is connected to the microcontroller, and the second terminal is connected to the microcontroller; the first terminal of the second switch is connected to the second terminal of the first switch, and the control terminal is connected to The microcontroller has a second end connected to the fan group; when the battery module is used, the microcontroller operates in an operating mode and controls the first switch and the second switch to conduct, the main battery power supply or the external A power supply provided by the power supply supplies power to the microcontroller and the fan group through the first switch and the second switch respectively; when the battery module is not in use, the microcontroller operates in the shutdown mode, and the Before entering the shutdown mode from the operating mode, the microcontroller controls the first switch and the second switch to turn off, and the main battery power supply or the external power supply stops supplying power to the microcontroller and the fan group. The circuit for detecting battery thermal runaway as described in claim 2 further includes a backup battery power supply, and the first end of the first switch is connected to the main battery power supply, the external power supply or the backup battery power supply; when the microcontroller After being restarted by the starting power supply, the microcontroller controls the first switch to be turned on, and the power supply provided by the backup battery power supply or the main battery power supply supplies power to the microcontroller through the first switch. The circuit for detecting thermal runaway of a battery as described in claim 3, wherein when the microcontroller senses the temperature of the battery core through the temperature sensor and determines that the battery core has thermal runaway, the microcontroller controls the third The two switches are turned on, and the power supply provided by the backup battery power or the main battery power supplies power to the fan group through the second switch. The fan group is activated by the power supply, and the microcontroller controls the activated fan. The group rotates at a predetermined speed or a high speed. The circuit for detecting battery thermal runaway as described in claim 1, wherein when the starting power exceeds a minimum starting voltage of the microcontroller, the microcontroller will be restarted. The circuit for detecting battery thermal runaway as described in claim 1, wherein a fuse is disposed between the battery cell and a power input and output port. When the microcontroller determines based on the temperature of the battery cell sensed by the temperature sensor, When the battery cell is thermally out of control, the microcontroller outputs a fusing current to the fuse to blow out the fuse. A method of detecting thermal runaway of a battery is applied to a battery module having at least one battery cell. The method of detecting thermal runaway of a battery includes: setting a microcontroller to operate in a shutdown mode when the battery module is not in use; A fan group is driven to rotate by a wind pressure; when the fan group is driven to rotate by the wind pressure, an induced electromotive force is formed to output a starting power to the microcontroller; The microcontroller is restarted with the startup power supply; and the restarted microcontroller uses a temperature sensor to sense the temperature of the battery core to determine whether the battery core is thermally runaway. The method for detecting battery thermal runaway as described in claim 7, wherein when the starting power exceeds a minimum starting voltage of the microcontroller, the microcontroller will restart. The method for detecting thermal runaway of a battery as described in claim 7, wherein after the microcontroller determines that the battery cell has thermal runaway, the method further includes: outputting a fuse current to the battery cell and a power input through the microcontroller A fuse between the output ports blows the fuse. The method for detecting thermal runaway of a battery as described in claim 7, wherein after the microcontroller determines that the battery cell has thermal runaway, the method further includes: restarting the fan group and rotating at a predetermined speed or a high speed. .

Images