Battery impedance measuring device and battery thermal runaway detection equipment

Abstract

The utility model discloses a battery impedance measuring device and battery thermal runaway detection equipment, and belongs to the technical field of batteries. The battery impedance measuring device comprises a first coupling capacitor and a second coupling capacitor. The positive and negative input ends of the differential amplifier are correspondingly connected with the second end of the first coupling capacitor and the second end of the second coupling capacitor respectively; the positive and negative input ends of the delay detection circuit are correspondingly connected with the positive and negative output ends of the differential amplifier respectively; the input end of the driver is connected with the output end of the delay detection circuit; the control end of the voltage adjusting circuit is connected with the output end of the driver, the first end is connected with a first voltage end, the second end is connected with the second end of the first coupling capacitor, and the third end is connected with the second end of the second coupling capacitor; and the positive and negative input ends of the differential analog-to-digital converter are correspondingly connected with the positive and negative output ends of the differential amplifier respectively. According to the invention, the voltage adjustment time of the coupling capacitor can be shortened, the adjustment efficiency is improved, the impedance measurement efficiency and accuracy are improved, and the thermal runaway detection efficiency and accuracy are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a battery impedance measuring device and a battery thermal runaway detection equipment. BACKGROUND

[0002] In the battery thermal runaway detection equipment, the impedance of the battery is measured by the battery impedance measuring device, and then the battery thermal runaway is detected by the processor according to the measured impedance. In the battery impedance measuring device, the voltage of the coupling capacitor needs to be adjusted to the common-mode voltage of the differential amplifier to meet the input requirements of the differential amplifier so as to measure the battery impedance. The related technology adjusts the voltage of the coupling capacitor by connecting a resistance divider. However, this adjustment method takes a long time, reduces the efficiency of battery impedance measurement, and thus reduces the efficiency of battery thermal runaway detection. CONTENT OF THE UTILITY MODEL

[0003] The application aims to at least solve one of the technical problems in the prior art. To this end, the application provides a battery impedance measuring device and a battery thermal runaway detection equipment, which can shorten the voltage adjustment time of the coupling capacitor, improve the voltage adjustment efficiency, improve the efficiency and accuracy of impedance measurement, and thus improve the efficiency and accuracy of battery thermal runaway detection.

[0004] In a first aspect, the application provides a battery impedance measuring device, comprising:

[0005] a first coupling capacitor and a second coupling capacitor, a first end of the first coupling capacitor and a first end of the second coupling capacitor are respectively connected to positive and negative measurement input terminals;

[0006] a differential amplifier, positive and negative input terminals of the differential amplifier are respectively connected to a second end of the first coupling capacitor and a second end of the second coupling capacitor;

[0007] a delay detection circuit, positive and negative input terminals of the delay detection circuit are respectively connected to positive and negative output terminals of the differential amplifier;

[0008] a driver, an input terminal of the driver is connected to an output terminal of the delay detection circuit;

[0009] a voltage adjustment circuit, a control terminal of the voltage adjustment circuit is connected to an output terminal of the driver, a first terminal of the voltage adjustment circuit is connected to a first voltage terminal, a second terminal of the voltage adjustment circuit is connected to the second end of the first coupling capacitor, and a third terminal of the voltage adjustment circuit is connected to the second end of the second coupling capacitor;

[0010] A differential analog-to-digital converter, positive and negative input terminals of the differential analog-to-digital converter correspondingly connect positive and negative output terminals of the differential amplifier, and positive and negative output terminals of the differential analog-to-digital converter correspondingly connect positive and negative measurement output terminals.

[0011] According to the battery impedance measurement device, when the voltage of the coupling capacitor needs to be adjusted, the delay detection circuit outputs a high-level signal, the driver outputs a high-level signal, the voltage adjustment circuit is controlled to be turned on, the voltage of the first voltage terminal is quickly adjusted to the voltage of the coupling capacitor through the voltage adjustment circuit, the voltage adjustment time of the coupling capacitor is shortened, the voltage adjustment efficiency is improved, and the impedance measurement efficiency is improved. Moreover, the delay detection circuit outputs a high-level signal in a delayed manner to avoid signal interference and improve measurement accuracy.

[0012] According to an embodiment of the present application, the voltage adjustment circuit comprises a first switch unit, a second switch unit, a first resistor and a second resistor.

[0013] The control terminals of the first switch unit and the second switch unit are connected to the control terminal of the voltage adjustment circuit, and the first terminals of the first switch unit and the second switch unit are connected to the first terminal of the voltage adjustment circuit; the second terminal of the first switch unit is connected to the first terminal of the first resistor, and the second terminal of the first resistor is connected to the second terminal of the voltage adjustment circuit; the second terminal of the second switch unit is connected to the first terminal of the second resistor, and the second terminal of the second resistor is connected to the third terminal of the voltage adjustment circuit.

[0014] According to an embodiment of the present application, the first switch unit comprises a first switch tube, a second switch tube and a first inverter, and the second switch unit comprises a third switch tube, a fourth switch tube and a second inverter.

[0015] The input terminal of the first inverter and the control terminal of the second switch tube are connected to the control terminal of the first switch unit, the control terminal of the first switch tube is connected to the output terminal of the first inverter, the first terminals of the first switch tube and the second switch tube are connected to the first terminal of the first switch unit, and the second terminals of the first switch tube and the second switch tube are connected to the second terminal of the first switch unit.

[0016] The input end of the second inverter and the control end of the third switch tube are connected to the control end of the second switch unit respectively, the control end of the fourth switch tube is connected to the output end of the second inverter, the first end of the third switch tube and the first end of the fourth switch tube are connected to the first end of the second switch unit respectively, and the second end of the third switch tube and the second end of the fourth switch tube are connected to the second end of the second switch unit respectively.

[0017] According to one embodiment of the present application, the voltage adjustment circuit further comprises a third resistor and a fourth resistor;

[0018] The first end of the third resistor is connected to the first voltage end, and the second end of the third resistor is connected to the second end of the first resistor; the first end of the fourth resistor is connected to the first voltage end, and the second end of the fourth resistor is connected to the second end of the second resistor.

[0019] According to one embodiment of the present application, the delay detection circuit comprises a detection circuit, a flip-flop, an oscillator and a counter;

[0020] The positive and negative input ends of the detection circuit are connected to the positive and negative input ends of the delay detection circuit respectively, the output end of the detection circuit is connected to the input end of the flip-flop, the clock end of the flip-flop is connected to the oscillator, the output end of the flip-flop is connected to the input end of the counter, and the output end of the counter is connected to the output end of the delay detection circuit.

[0021] According to one embodiment of the present application, the detection circuit comprises a first comparator, a second comparator, a third comparator, a fourth comparator, a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, a fifth resistor and a sixth resistor;

[0022] The positive and negative input ends of the first comparator are connected to a first reference voltage end and the negative input end of the detection circuit respectively, the output end of the first comparator is connected to the control end of the fifth switch tube, the first end of the fifth switch tube is connected to the first end of the fifth resistor and the output end of the detection circuit respectively, the second end of the fifth resistor is connected to a second voltage end, and the second end of the fifth switch tube is grounded;

[0023] The positive and negative input ends of the second comparator are connected to the negative input end of the detection circuit and a second reference voltage end respectively, the output end of the second comparator is connected to the control end of the sixth switch tube, the first end of the sixth switch tube is connected to the output end of the detection circuit, and the second end of the sixth switch tube is grounded;

[0024] The positive and negative input terminals of the third comparator are connected to the first reference voltage terminal and the positive input terminal of the detection circuit respectively, the output terminal of the third comparator is connected to the control terminal of the seventh switch tube, the first terminal of the seventh switch tube is connected to the first terminal of the sixth resistor and the output terminal of the detection circuit respectively, the second terminal of the sixth resistor is connected to the second voltage terminal, and the second terminal of the seventh switch tube is grounded.

[0025] The positive and negative input terminals of the fourth comparator are connected to the positive input terminal of the detection circuit and the second reference voltage terminal respectively, the output terminal of the fourth comparator is connected to the control terminal of the eighth switch tube, the first terminal of the eighth switch tube is connected to the output terminal of the detection circuit, and the second terminal of the eighth switch tube is grounded.

[0026] According to an embodiment of the present application, the detection circuit further comprises a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor.

[0027] The seventh resistor is connected between the output terminal of the first comparator and the control terminal of the fifth switch tube, the eighth resistor is connected between the output terminal of the second comparator and the control terminal of the sixth switch tube, the ninth resistor is connected between the output terminal of the third comparator and the control terminal of the seventh switch tube, and the tenth resistor is connected between the output terminal of the fourth comparator and the control terminal of the eighth switch tube.

[0028] According to an embodiment of the present application, the delay detection circuit further comprises a monostable circuit.

[0029] The input terminal of the monostable circuit is connected to the output terminal of the detection circuit, and the output terminal of the monostable circuit is connected to the reset terminal of the counter.

[0030] According to an embodiment of the present application, the battery impedance measurement device further comprises an eleventh resistor and a twelfth resistor.

[0031] The second terminal of the first coupling capacitor is connected to the second terminal of the voltage adjustment circuit and the positive input terminal of the differential amplifier through the eleventh resistor respectively, and the second terminal of the second coupling capacitor is connected to the third terminal of the voltage adjustment circuit and the negative input terminal of the differential amplifier through the twelfth resistor respectively.

[0032] In a second aspect, the present application provides a battery thermal runaway detection device, comprising the battery impedance measurement device, the alternating current generator, the positive and negative alternating current output terminals, the processor, the temperature and humidity collector, the display screen and the memory of the first aspect.

[0033] The processor is respectively connected with the positive and negative measurement output end of the battery impedance measurement device, the AC generator, the temperature and humidity collector, the display screen and the memory, and the AC generator is further connected with the positive and negative AC output end.

[0034] The one or more technical solutions in the embodiments of the application have at least one of the following technical effects:

[0035] By setting the delay detection circuit, the driver and the voltage adjustment circuit, when the voltage of the coupling capacitor needs to be adjusted, the delay detection circuit outputs a high level signal, the driver outputs a high level signal, the voltage adjustment circuit is turned on, and the voltage of the first voltage end is adjusted quickly by the voltage adjustment circuit to adjust the voltage of the coupling capacitor, so that the voltage adjustment time of the coupling capacitor is shortened, the voltage adjustment efficiency is improved, and the efficiency of impedance measurement is improved. The efficiency and accuracy of the battery thermal runaway detection are improved.

[0036] Additional aspects and advantages of the application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0037] The above and / or additional aspects and advantages of the application will become apparent and be readily understood from the following description, taken in connection with the accompanying drawings, in which:

[0038] Figure 1 is a structural schematic diagram of a battery impedance measurement device provided by the embodiments of the application;

[0039] Figure 2 is a structural schematic diagram of a battery thermal runaway detection device provided by the embodiments of the application.

[0040] Reference signs:

[0041] Positive measurement input terminal Vi+, negative measurement input terminal Vi-, first coupling capacitor C1, second coupling capacitor C2, differential amplifier D1, voltage adjustment circuit 1, delay detection circuit 2, driver 3, differential analog-to-digital converter 4, positive measurement output terminal Vo+, negative measurement output terminal Vo-, first switch unit 11, second switch unit 12, first resistor R3, second resistor R6, first switch tube Q1, second switch tube Q2, first inverter N1, third switch tube Q3, fourth switch tube Q4, second inverter N2, third resistor R4, fourth resistor R5, first voltage terminal V1, positive input terminal IN+ of differential amplifier D1, negative input terminal IN- of differential amplifier D1, positive output terminal OUT+ of differential amplifier D1, negative output terminal OUT- of differential amplifier D1, detection circuit 21, trigger 22, oscillator 23, counter 24, input terminal of trigger 22 , a clock terminal SCK of the trigger 22, an output terminal Q of the trigger 22, a reset terminal RESET of the counter 24, a first comparator D2, a second comparator D3, a third comparator D4, a fourth comparator D5, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a fifth resistor R11, a sixth resistor R12, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a monostable circuit 25, an eleventh resistor R1, a twelfth resistor R2, a second voltage terminal V2, a first reference voltage terminal V3, a second reference voltage terminal V4, a battery impedance measuring device 10, a processor 20, an AC generator 30, a display screen 40, a memory 50, a temperature and humidity collector 60, a positive AC output terminal A+, and a negative AC output terminal A-. DETAILED DESCRIPTION

[0042] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and are not to be construed as limiting the present application.

[0043] The battery impedance measurement device and battery thermal runaway detection equipment provided in the embodiments of the present application are described below with reference to the accompanying drawings.

[0044] An embodiment of the present application provides a battery impedance measuring device.

[0045] like Figure 1 As shown, the battery impedance measuring device includes a first coupling capacitor C1, a second coupling capacitor C2, a differential amplifier D1, a delay detection circuit 2, a driver 3, a voltage adjustment circuit 1 and a differential analog-to-digital converter 4.

[0046] The first end of the first coupling capacitor C1 and the first end of the second coupling capacitor C2 are respectively connected to the positive and negative measurement input terminals. The first end of the first coupling capacitor C1 is connected to the positive measurement input terminal Vi+, and the first end of the second coupling capacitor C2 is connected to the negative measurement input terminal Vi-.

[0047] When measuring the impedance of the battery, the positive and negative electrodes of the battery are connected to the positive and negative measurement input terminals, that is, the positive electrode of the battery is connected to the positive measurement input terminal Vi+, and the negative electrode of the battery is connected to the negative measurement input terminal Vi-. The measured battery includes but is not limited to a lithium battery. The first coupling capacitor C1 and the second coupling capacitor C2 are used to pass AC signals and block DC signals.

[0048] When the battery is connected, an AC signal is input to the battery, which can be provided by an AC signal generator in the related art, which is not limited here. At this time, the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is not the common-mode voltage of the differential amplifier D1, which does not meet the input requirements of the differential amplifier D1, so it is necessary to adjust the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 to meet the input requirements of the differential amplifier D1. For example, the common-mode voltage is 1.2V, when the battery is connected, the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 will be pulled to the battery voltage, so that the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is generally above 3.3V. By adjusting the voltage of the first coupling capacitor C1 and the second coupling capacitor C2, the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is 1.2V.

[0049] The positive and negative input terminals of the differential amplifier D1 are respectively connected to the second end of the first coupling capacitor C1 and the second end of the second coupling capacitor C2. The positive input terminal IN+ of the differential amplifier D1 is connected to the second end of the first coupling capacitor C1, and the negative input terminal IN- of the differential amplifier D1 is connected to the second end of the second coupling capacitor C2.

[0050] When the voltages of the first coupling capacitor C1 and the second coupling capacitor C2 are not the common-mode voltage of the differential amplifier D1, the voltages of the positive output end and the negative output end of the differential amplifier D1 are greater than the first reference voltage or less than the second reference voltage, and the first reference voltage is greater than the second reference voltage; when the voltages of the first coupling capacitor C1 and the second coupling capacitor C2 are the common-mode voltage of the differential amplifier D1, the voltages of the positive output end and the negative output end of the differential amplifier D1 are between the first reference voltage and the second reference voltage (i.e. less than the first reference voltage and greater than the second reference voltage). For example, the voltages of the first coupling capacitor C1 and the second coupling capacitor C2 are greater than or equal to 3.3 V, causing the differential amplifier D1 to be saturated, at this time, the positive input end IN+ of the differential amplifier D1 is pulled high, the negative input end IN- of the differential amplifier D1 is pulled low, causing the voltage of the positive output end OUT+ of the differential amplifier D1 to be higher than the first reference voltage (e.g. 2.6 V), and the voltage of the negative output end OUT- of the differential amplifier D1 to be lower than the second reference voltage (e.g. 0.2 V).

[0051] The positive input end and the negative input end of the delay detection circuit 2 correspond to the positive output end and the negative output end of the differential amplifier D1, respectively. Specifically, the positive input end of the delay detection circuit 2 is connected to the positive output end OUT+ of the differential amplifier D1, and the negative input end of the delay detection circuit 2 is connected to the negative output end OUT- of the differential amplifier D1.

[0052] The delay detection circuit 2 detects the voltages of the positive output end and the negative output end of the differential amplifier D1. When the voltages of the positive output end and the negative output end of the differential amplifier D1 are greater than the first reference voltage or less than the second reference voltage, the output end of the delay detection circuit 2 outputs a high-level signal; when the voltages of the positive output end and the negative output end of the differential amplifier D1 are between the first reference voltage and the second reference voltage, the output end of the delay detection circuit 2 outputs a low-level signal.

[0053] It should be noted that when the voltages of the positive output end and the negative output end of the differential amplifier D1 are greater than the first reference voltage or less than the second reference voltage, the delay detection circuit 2 can output a high-level signal after a certain time delay.

[0054] The input end of the driver 3 is connected to the output end of the delay detection circuit 2.

[0055] When the output end of the delay detection circuit 2 outputs a high-level signal, the input end of the driver 3 inputs a high-level signal, and the output end of the driver 3 outputs a high-level signal; when the output end of the delay detection circuit 2 outputs a low-level signal, the input end of the driver 3 inputs a low-level signal, and the output end of the driver 3 outputs a low-level signal.

[0056] It should be noted that the driver 3 can use a standard driver in the related art, such as a same-phase driver, which inputs a low-level signal and outputs a low-level signal, and inputs a high-level signal and outputs a high-level signal.

[0057] The control end of the voltage adjustment circuit 1 is connected to the output end of the driver 3, the first end of the voltage adjustment circuit 1 is connected to the first voltage end V1, the second end of the voltage adjustment circuit 1 is connected to the second end of the first coupling capacitor C1, and the third end of the voltage adjustment circuit 1 is connected to the second end of the second coupling capacitor C2.

[0058] The high and low level signals of the output end of the driver 3 control the voltage adjustment circuit 1 to be in the on state or the off state. When the output end of the driver 3 outputs a high level signal, the control end of the voltage adjustment circuit 1 inputs a high level signal, the voltage adjustment circuit 1 is turned on, and the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is adjusted by the voltage of the first voltage end V1, so that the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is adjusted to the common mode voltage. The voltage of the first voltage end V1 can be the common mode voltage, such as 1.2V. When the output end of the driver 3 outputs a low level signal, the control end of the voltage adjustment circuit 1 inputs a low level signal, the voltage adjustment circuit 1 is turned off, and the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is not adjusted.

[0059] The positive and negative input ends of the differential analog-to-digital converter 4 are respectively connected to the positive and negative output ends of the differential amplifier D1, and the positive and negative output ends of the differential analog-to-digital converter 4 are respectively connected to the positive and negative measurement output ends. The positive input end of the differential analog-to-digital converter 4 is connected to the positive output end OUT+ of the differential amplifier D1, the negative input end of the differential analog-to-digital converter 4 is connected to the negative output end OUT- of the differential amplifier D1, the positive output end of the differential analog-to-digital converter 4 is connected to the positive measurement output end Vo+, and the negative output end of the differential analog-to-digital converter 4 is connected to the negative measurement output end Vo-.

[0060] After the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is adjusted to the common mode voltage, the voltage of the positive and negative output ends of the differential amplifier D1 is the measured battery impedance voltage. The differential analog-to-digital converter 4 performs analog-to-digital conversion on the measured battery impedance voltage to obtain the battery impedance. The battery impedance is output through the positive and negative measurement output ends, and the measurement of the battery impedance is completed.

[0061] When the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is not the common mode voltage, the voltage of the positive and negative output ends of the differential amplifier D1 is greater than the first reference voltage or less than the second reference voltage, the delay detection circuit 2 outputs a high level signal, the driver 3 outputs a high level signal, the voltage adjustment circuit 1 is controlled to be turned on, the voltage of the first voltage end V1 quickly adjusts the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 to the common mode voltage through the voltage adjustment circuit 1, shortens the voltage adjustment time of the coupling capacitor, improves the voltage adjustment efficiency, and thus improves the efficiency of the impedance measurement. Moreover, the delay detection circuit 2 can delay the output of the high level signal to avoid signal interference and improve the accuracy of the measurement.

[0062] In some embodiments, the voltage adjustment circuit 1 comprises a first switch unit 11, a second switch unit 12, a first resistor R3 and a second resistor R6. The control terminals of the first switch unit 11 and the second switch unit 12 are connected to the control terminal of the voltage adjustment circuit 1, i.e. the control terminals of the first switch unit 11 and the second switch unit 12 are connected to the output terminal of the driver 3. The first terminals of the first switch unit 11 and the second switch unit 12 are connected to the first terminal of the voltage adjustment circuit 1, i.e. the first terminals of the first switch unit 11 and the second switch unit 12 are connected to the first voltage terminal V1. The second terminal of the first switch unit 11 is connected to the first terminal of the first resistor R3, and the second terminal of the first resistor R3 is connected to the second terminal of the voltage adjustment circuit 1, i.e. the second terminal of the first resistor R3 is connected to the second terminal of the first coupling capacitor C1. The second terminal of the second switch unit 12 is connected to the first terminal of the second resistor R6, and the second terminal of the second resistor R6 is connected to the third terminal of the voltage adjustment circuit 1, i.e. the second terminal of the second resistor R6 is connected to the second terminal of the second coupling capacitor C2.

[0063] The high and low level signals of the output terminal of the driver 3 control the first switch unit 11 and the second switch unit 12 to be in the on state or the off state. When the output terminal of the driver 3 outputs a high level signal, the control terminals of the first switch unit 11 and the second switch unit 12 input the high level signal, and the first switch unit 11 and the second switch unit 12 are turned on. The voltage of the first voltage terminal V1 adjusts the voltage of the first coupling capacitor C1 through the first resistor R3, and adjusts the voltage of the first coupling capacitor C1 to the common mode voltage. The voltage of the first voltage terminal V1 adjusts the voltage of the second coupling capacitor C2 through the second resistor R6, and adjusts the voltage of the second coupling capacitor C2 to the common mode voltage. When the output terminal of the driver 3 outputs a low level signal, the control terminals of the first switch unit 11 and the second switch unit 12 input the low level signal, and the first switch unit 11 and the second switch unit 12 are turned off, without the need to adjust the voltages of the first coupling capacitor C1 and the second coupling capacitor C2.

[0064] In some embodiments, the first switch unit 11 comprises a first switch tube Q1, a second switch tube Q2 and a first inverter N1, and the second switch unit 12 comprises a third switch tube Q3, a fourth switch tube Q4 and a second inverter N2.

[0065] The input end of the first inverter N1 and the control end of the second switch tube Q2 are connected to the control end of the first switch unit 11 respectively, that is, the input end of the first inverter N1 and the control end of the second switch tube Q2 are connected to the output end of the driver 3 respectively. The control end of the first switch tube Q1 is connected to the output end of the first inverter N1, and the first end of the first switch tube Q1 and the first end of the second switch tube Q2 are connected to the first end of the first switch unit 11 respectively, that is, the first end of the first switch tube Q1 and the first end of the second switch tube Q2 are connected to the first voltage end V1 respectively. The second end of the first switch tube Q1 and the second end of the second switch tube Q2 are connected to the second end of the first switch unit 11 respectively, that is, the second end of the first switch tube Q1 and the second end of the second switch tube Q2 are connected to the first end of the first resistor R3 respectively.

[0066] The input end of the second inverter N2 and the control end of the third switch tube Q3 are connected to the control end of the second switch unit 12 respectively, that is, the input end of the second inverter N2 and the control end of the third switch tube Q3 are connected to the output end of the driver 3 respectively. The control end of the fourth switch tube Q4 is connected to the output end of the second inverter N2, and the first end of the third switch tube Q3 and the first end of the fourth switch tube Q4 are connected to the first end of the second switch unit 12 respectively, that is, the first end of the third switch tube Q3 and the first end of the fourth switch tube Q4 are connected to the first voltage end V1 respectively. The second end of the third switch tube Q3 and the second end of the fourth switch tube Q4 are connected to the second end of the second switch unit 12 respectively, that is, the second end of the third switch tube Q3 and the second end of the fourth switch tube Q4 are connected to the first end of the second resistor R6 respectively.

[0067] Among them, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 can be field effect transistors, such as P-type field effect transistors or N-type field effect transistors. Among them, the control end of the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 can be the gate of the transistor, one of the first end and the second end can be the source of the transistor, and the other can be the drain of the transistor.

[0068] The high and low level signals of the output end of the driver 3 control the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 to be in the on state or the off state. When the output end of the driver 3 outputs a high level signal, the control end of the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 inputs a high level signal, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are turned on. The voltage of the first voltage end V1 adjusts the voltage of the first coupling capacitor C1 through the first resistor R3 (low internal resistance channel), and quickly adjusts the voltage of the first coupling capacitor C1 to the common mode voltage. The voltage of the first voltage end V1 adjusts the voltage of the second coupling capacitor C2 through the second resistor R6 (low internal resistance channel), and quickly adjusts the voltage of the second coupling capacitor C2 to the common mode voltage. When the output end of the driver 3 outputs a low level signal, the control end of the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 inputs a low level signal, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are turned off, and there is no need to adjust the voltage of the first coupling capacitor C1 and the second coupling capacitor C2.

[0069] In some embodiments, the voltage adjustment circuit 1 further comprises a third resistor R4 and a fourth resistor R5. The first end of the third resistor R4 is connected to the first voltage end V1, and the second end of the third resistor R4 is connected to the second end of the first resistor R3; the first end of the fourth resistor R5 is connected to the first voltage end V1, and the second end of the fourth resistor R5 is connected to the second end of the second resistor R6.

[0070] Among them, the third resistor R4 and the fourth resistor R5 are current limiting resistors, which are used to limit the input of excessive current to protect the circuit.

[0071] In some embodiments, the delay detection circuit 2 comprises a detection circuit 21, a flip-flop 22, an oscillator 23 and a counter 24. The positive and negative input ends of the detection circuit 21 correspond to the positive and negative input ends of the delay detection circuit 2, that is, the positive and negative input ends of the detection circuit 21 correspond to the positive and negative output ends of the differential amplifier D1, that is, the positive input end of the detection circuit 21 is connected to the positive output end OUT+ of the differential amplifier D1, and the negative input end of the detection circuit 21 is connected to the negative output end OUT- of the differential amplifier D1. The output end of the detection circuit 21 is connected to the input end of the flip-flop 22 , the clock end SCK of the flip-flop 22 is connected to the oscillator 23, the output end Q of the flip-flop 22 is connected to the input end of the counter 24, and the output end of the counter 24 is connected to the output end of the delay detection circuit 2, that is, the output end of the counter 24 is connected to the input end of the driver 3. Among them, the flip-flop 22 can be a D flip-flop.

[0072] The detection circuit 21 detects the voltage of the positive and negative output terminals of the differential amplifier D1. When the voltage of the positive and negative output terminals of the differential amplifier D1 is greater than the first reference voltage or less than the second reference voltage, the output terminal of the detection circuit 21 outputs a low-level signal, the flip-flop 22 is triggered, the clock terminal SCK of the flip-flop 22 generates a clock signal through the oscillator 23 (OSC), and the output terminal Q of the flip-flop 22 sends a pulse clock to the counter 24. The frequency of the oscillator 23 can be 100 kHZ, that is, each clock period can be 10 microseconds. The counter 24 counts the pulse clock, and when the count value reaches 200 pulses, the time is 2 milliseconds, and the output terminal of the counter 24 outputs a high-level signal, so that the driver 3 generates a high-level signal and outputs to the control terminal of the voltage adjustment circuit 1.

[0073] When the voltage of the positive and negative output terminals of the differential amplifier D1 is between the first reference voltage and the second reference voltage, the output terminal of the detection circuit 21 outputs a high-level signal, the input terminal of the flip-flop 22 inputs a high-level signal, the flip-flop 22 is not triggered, and the output terminal of the counter 24 outputs a low-level signal, so that the output terminal of the driver 3 outputs a low-level signal to the control terminal of the voltage adjustment circuit 1.

[0074] The detection circuit 21 in the embodiment judges whether the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is a common-mode voltage by detecting the voltage of the positive and negative output terminals of the differential amplifier D1. When the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is not a common-mode voltage, the voltage of the positive and negative output terminals of the differential amplifier D1 is greater than the first reference voltage or less than the second reference voltage, the detection circuit 21 outputs a low-level signal, the flip-flop 22 is triggered, and the driver 3 outputs a high-level signal through the counter 24 to control the voltage adjustment circuit 1 to turn on, so that the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 is quickly adjusted to a common-mode voltage, and the voltage adjustment efficiency is improved. In addition, the counter 24 counts the pulse signal output by the flip-flop 22, and outputs a high-level signal to make the driver 3 output a high-level signal after a certain number of pulses are counted, that is, after a certain time delay, so as to improve the voltage adjustment efficiency while avoiding signal interference and improving the measurement accuracy.

[0075] In some embodiments, the detection circuit 21 includes a first comparator D2, a second comparator D3, a third comparator D4, a fourth comparator D5, a fifth switch tube Q5, a sixth switch tube Q6, a seventh switch tube Q7, an eighth switch tube Q8, a fifth resistor R11, and a sixth resistor R12.

[0076] The positive and negative input terminals of the first comparator D2 are connected to the first reference voltage terminal V3 and the negative input terminal of the detection circuit 21, respectively. That is, the positive input terminal of the first comparator D2 is connected to the first reference voltage terminal V3, and the negative input terminal of the first comparator D2 is connected to the negative output terminal OUT- of the differential amplifier D1. The output terminal of the first comparator D2 is connected to the control terminal of the fifth switch tube Q5. The first terminal of the fifth switch tube Q5 is connected to the first terminal of the fifth resistor R11 and the output terminal of the detection circuit 21, respectively. That is, the first terminal of the fifth switch tube Q5 is connected to the first terminal of the fifth resistor R11 and the input terminal of the trigger 22. The second end of the fifth resistor R11 is connected to the second voltage terminal V2, and the second end of the fifth switch tube Q5 is grounded.

[0077] The positive and negative input terminals of the second comparator D3 are connected to the negative input terminal of the detection circuit 21 and the second reference voltage terminal V4, respectively. That is, the positive input terminal of the second comparator D3 is connected to the negative output terminal OUT- of the differential amplifier D1, and the negative input terminal of the second comparator D3 is connected to the second reference voltage terminal V4. The output terminal of the second comparator D3 is connected to the control terminal of the sixth switch Q6. The first terminal of the sixth switch Q6 is connected to the output terminal of the detection circuit 21. That is, the first terminal of the sixth switch Q6 is connected to the input terminal of the trigger 22. The second terminal of the sixth switch tube Q6 is grounded.

[0078] The positive and negative input terminals of the third comparator D4 are respectively connected to the first reference voltage terminal V3 and the positive input terminal of the detection circuit 21. That is, the positive input terminal of the third comparator D4 is connected to the first reference voltage terminal V3, and the negative input terminal of the third comparator D4 is connected to the positive output terminal OUT+ of the differential amplifier D1. The output terminal of the third comparator D4 is connected to the control terminal of the seventh switch tube Q7. The first terminal of the seventh switch tube Q7 is respectively connected to the first terminal of the sixth resistor R12 and the output terminal of the detection circuit 21. That is, the first terminal of the seventh switch tube Q7 is respectively connected to the first terminal of the sixth resistor R12 and the input terminal of the trigger 22. The second end of the sixth resistor R12 is connected to the second voltage terminal V2, and the second end of the seventh switch tube Q7 is grounded.

[0079] The positive and negative input terminals of the fourth comparator D5 are respectively connected to the positive input terminal of the detection circuit 21 and the second reference voltage terminal V4. That is, the positive input terminal of the fourth comparator D5 is connected to the positive output terminal OUT+ of the differential amplifier D1, and the negative input terminal of the fourth comparator D5 is connected to the second reference voltage terminal V4. The output terminal of the fourth comparator D5 is connected to the control terminal of the eighth switch tube Q8. The first terminal of the eighth switch tube Q8 is connected to the output terminal of the detection circuit 21. That is, the first terminal of the eighth switch tube Q8 is connected to the input terminal of the trigger 22. The second terminal of the eighth switch tube Q8 is grounded.

[0080] The voltage of the first reference voltage terminal V3 is the first reference voltage, such as 2.6V, the voltage of the second reference voltage terminal V4 is the second reference voltage, such as 0.2V, and the voltage of the second voltage terminal V2 can be 3.3V. The fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the eighth switch tube Q8 can be triodes, such as NPN triodes or PNP triodes. The control end of the fifth switch tube Q5, the sixth switch tube Q6, the seventh switch tube Q7 and the eighth switch tube Q8 can be the base of the triode, one of the first end and the second end can be the collector of the triode, and the other can be the emitter of the triode.

[0081] The first comparator D2 and the second comparator D3 detect the voltage of the negative output end OUT- of the differential amplifier D1. When the voltage of the negative output end OUT- of the differential amplifier D1 is between the first reference voltage and the second reference voltage, the first comparator D2 and the second comparator D3 both output high-level signals, the fifth switch tube Q5 and the sixth switch tube Q6 are both not working, and the first end of the fifth switch tube Q5 and the first end of the sixth switch tube Q6 both output high-level signals. When the voltage of the negative output end OUT- of the differential amplifier D1 is greater than the first reference voltage, the first comparator D2 outputs a low-level signal, the fifth switch tube Q5 works, and the first end of the fifth switch tube Q5 outputs a low-level signal. When the voltage of the negative output end OUT- of the differential amplifier D1 is less than the second reference voltage, the second comparator D3 outputs a low-level signal, the sixth switch tube Q6 works, and the first end of the sixth switch tube Q6 outputs a low-level signal.

[0082] The third comparator D4 and the fourth comparator D5 detect the voltage of the positive output end OUT+ of the differential amplifier D1. When the voltage of the positive output end OUT+ of the differential amplifier D1 is between the first reference voltage and the second reference voltage, the third comparator D4 and the fourth comparator D5 both output high-level signals, the seventh switch tube Q7 and the eighth switch tube Q8 are both not working, and the first end of the seventh switch tube Q7 and the first end of the eighth switch tube Q8 both output high-level signals. When the voltage of the positive output end OUT+ of the differential amplifier D1 is greater than the first reference voltage, the third comparator D4 outputs a low-level signal, the seventh switch tube Q7 works, and the first end of the seventh switch tube Q7 outputs a low-level signal. When the voltage of the positive output end OUT+ of the differential amplifier D1 is less than the second reference voltage, the fourth comparator D5 outputs a low-level signal, the eighth switch tube Q8 works, and the first end of the eighth switch tube Q8 outputs a low-level signal.

[0083] The input end of the flip-flop 22 The first end of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 receives a signal. The fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 form a AND logic circuit. When the signal of the first end of any one of the switches is a low level signal, the flip-flop 22 triggers, the counter 24 outputs a high level signal to make the driver 3 output a high level signal, and the voltage adjustment circuit 1 is turned on to quickly adjust the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 to the common mode voltage.

[0084] In some embodiments, the detection circuit 21 further comprises a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a tenth resistor R10. The seventh resistor R7 is connected between the output end of the first comparator D2 and the control end of the fifth switch Q5, the eighth resistor R8 is connected between the output end of the second comparator D3 and the control end of the sixth switch Q6, the ninth resistor R9 is connected between the output end of the third comparator D4 and the control end of the seventh switch Q7, and the tenth resistor R10 is connected between the output end of the fourth comparator D5 and the control end of the eighth switch Q8.

[0085] The seventh resistor R7, the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 are current limiting resistors, which are used to limit the input of excessive current to protect the circuit.

[0086] In some embodiments, the delay detection circuit 2 further comprises a monostable circuit 25. The input end of the monostable circuit 25 is connected to the output end of the detection circuit 21, and the output end of the monostable circuit 25 is connected to the reset end RESET of the counter 24.

[0087] The signal of the first end of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 is also output to the monostable circuit 25. When the first end of any one of the fifth switch Q5, the sixth switch Q6, the seventh switch Q7 and the eighth switch Q8 outputs a low level signal, the monostable circuit 25 can generate a 20 millisecond low level delay signal to reset the counter 24, so that the internal register number of the counter 24 is 0.

[0088] After the counter 24 is reset, a low level signal is output, so that the driver 3 outputs a low level signal, the voltage adjustment circuit 1 is turned off, and the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 does not need to be adjusted. When the next battery is connected for impedance measurement, the voltage of the first coupling capacitor C1 and the second coupling capacitor C2 can be adjusted again.

[0089] It should be noted that the monostable circuit 25 can be a standard monostable circuit in the related art. The monostable circuit has only one stable state (steady state), which is maintained for a long time without external triggering; when triggered by a trigger signal (input low level signal), the monostable circuit temporarily enters a temporary stable state, and automatically returns to the steady state after a period of time. The duration of the temporary stable state of the monostable circuit is determined by the internal parameters of the circuit (such as resistance, capacitance value). For example, the monostable circuit can be a transistor cross-coupled structure, that is, a positive feedback network composed of two-stage transistors (such as NPN or PNP type) cross-coupled by resistance and capacitance.

[0090] In some embodiments, the battery impedance measurement device further comprises an eleventh resistor R1 and a twelfth resistor R2. The second end of the first coupling capacitor C1 is connected to the second end of the voltage adjustment circuit 1 and the positive input end IN+ of the differential amplifier D1 through the eleventh resistor R1, respectively, and the second end of the second coupling capacitor C2 is connected to the third end of the voltage adjustment circuit 1 and the negative input end IN- of the differential amplifier D1 through the twelfth resistor R2.

[0091] Among them, the eleventh resistor R1 and the twelfth resistor R2 are current limiting resistors, which are used to limit excessive current input to protect the circuit.

[0092] In summary, according to the battery impedance measurement device provided by the embodiment of the present application, by setting the delay detection circuit 2, the driver 3 and the voltage adjustment circuit 1, when it is necessary to adjust the voltage of the coupling capacitor, the delay detection circuit 2 outputs a high level signal, the driver 3 outputs a high level signal, and the voltage adjustment circuit 1 is controlled to be turned on. The voltage at the first voltage end V1 is adjusted quickly by the voltage adjustment circuit 1 to adjust the voltage of the coupling capacitor, shorten the voltage adjustment time of the coupling capacitor, improve the voltage adjustment efficiency, and thus improve the efficiency of impedance measurement. Moreover, the delay detection circuit 2 outputs a high level to avoid signal interference and improve measurement accuracy.

[0093] Correspondingly, the embodiment of the present application also provides a battery thermal runaway detection device.

[0094] As Figure 2As shown, the battery thermal runaway detection device provided by the embodiment of the application includes a battery impedance measurement device 10, a processor 20, an alternating current generator 30, positive and negative alternating current output terminals, a temperature and humidity collector 60, a display screen 40 and a memory 50. The battery impedance measurement device 10 is the battery impedance measurement device in the above embodiment, which will not be described in detail here. The processor 20 is connected with the positive and negative measurement output terminals of the battery impedance measurement device 10, that is, the processor 20 is connected with the positive measurement output terminal Vo+ and the negative measurement output terminal Vo- respectively. The processor 20 is also connected with the alternating current generator 30, the temperature and humidity collector 60, the display screen 40 and the memory 50 respectively. The alternating current generator 30 is also connected with the positive and negative alternating current output terminals, that is, the alternating current generator 30 is connected with the positive alternating current output terminal A+ and the negative alternating current output terminal A- respectively.

[0095] When detecting the thermal runaway of the battery, the positive and negative electrodes of the battery are connected with the positive and negative measurement input terminals respectively, and the positive and negative electrodes of the battery are connected with the positive and negative alternating current output terminals respectively. The alternating current generator 30 generates an alternating current signal and transmits the alternating current signal to the battery through the positive and negative alternating current output terminals. The battery impedance measurement device 10 measures the impedance of the battery and outputs the impedance of the battery through the positive and negative measurement output terminals. The frequency of the alternating current signal generated by the alternating current generator 30 can be set by the processor 20. The processor 20 obtains the impedance of the battery measured by the battery impedance measurement device 10 through the positive and negative measurement output terminals, and detects whether the battery has a thermal runaway risk according to the impedance of the battery.

[0096] For example, during the thermal runaway process of a lithium battery, a series of chemical reactions occur in the internal materials, causing changes in the internal structure of the battery, thereby changing the internal resistance.

[0097] Therefore, by detecting the impedance change of the battery, it can be determined whether the battery to be measured has a thermal runaway risk. For example, the impedance of the battery can include a transfer impedance. If the transfer impedance of the battery rapidly decreases, it indicates that the battery is rapidly heating up, and it can be determined that the battery has a thermal runaway risk. Otherwise, it can be determined that the battery to be measured does not have a thermal runaway risk.

[0098] It should be noted that the processor 20 is a processor in the prior art, and the processor 20 can use any detection method in the prior art to detect whether the battery has a thermal runaway risk according to the impedance of the battery, which will not be limited here.

[0099] The temperature and humidity collector 60 collects the temperature and humidity of the environment in which the battery is located. Detecting the thermal runaway of the battery in different temperature and humidity environments helps to analyze the influence of the temperature and humidity environment on the thermal runaway of the battery in the subsequent analysis.

[0100] The display screen 40 can display the impedance measurement result and the thermal runaway detection result. The processor 20 outputs the impedance of the battery to the display screen 40 after obtaining the impedance of the battery, and the display screen 40 displays the measured impedance of the battery. The processor 20 outputs the thermal runaway detection result (thermal runaway risk exists or thermal runaway risk does not exist) to the display screen 40 after detecting whether the battery has a thermal runaway risk, and the display screen 40 displays the thermal runaway detection result.

[0101] The memory 50 can store the impedance measurement result, the thermal runaway detection result, and the like, for subsequent query.

[0102] According to the battery thermal runaway detection device provided by the embodiment of the present application, by setting the delay detection circuit, the driver and the voltage adjustment circuit, when it is necessary to adjust the voltage of the coupling capacitor, the delay detection circuit outputs a high-level signal, the driver outputs a high-level signal, the voltage adjustment circuit is controlled to be turned on, and the voltage of the first voltage terminal is quickly adjusted by the voltage adjustment circuit to adjust the voltage of the coupling capacitor, thereby shortening the voltage adjustment time of the coupling capacitor, improving the voltage adjustment efficiency, improving the efficiency of impedance measurement, improving the thermal runaway detection efficiency, avoiding signal interference by the delay output of the delay detection circuit, improving the detection accuracy, and quickly and accurately detecting whether the battery to be measured has a thermal runaway risk, thereby effectively eliminating the safety hazard of the battery.

[0103] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually a class, not limited to the number of objects, for example, the first object can be one or more.

[0104] In the description of the present application, the meaning of "a plurality of" is two or more.

[0105] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the description of the present application, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0106] While the embodiments of the application have been shown and described, it is to be understood that the embodiments can be varied, modified, substituted and changed by those skilled in the art without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery impedance measurement device, characterized by, include: a first coupling capacitor and a second coupling capacitor, wherein a first end of the first coupling capacitor and a first end of the second coupling capacitor are connected to a positive and negative measurement input terminal respectively; a differential amplifier, wherein the positive and negative input terminals of the differential amplifier are respectively connected to the second terminal of the first coupling capacitor and the second terminal of the second coupling capacitor; a delay detection circuit, wherein the positive and negative input terminals of the delay detection circuit are respectively connected to the positive and negative output terminals of the differential amplifier; A driver, wherein an input end of the driver is connected to an output end of the delay detection circuit; a voltage regulating circuit, wherein a control end of the voltage regulating circuit is connected to the output end of the driver, a first end of the voltage regulating circuit is connected to the first voltage end, a second end of the voltage regulating circuit is connected to the second end of the first coupling capacitor, and a third end of the voltage regulating circuit is connected to the second end of the second coupling capacitor; A differential analog-to-digital converter, wherein the positive and negative input terminals of the differential analog-to-digital converter are respectively connected to the positive and negative output terminals of the differential amplifier, and the positive and negative output terminals of the differential analog-to-digital converter are respectively connected to the positive and negative measurement output terminals.

2. The battery impedance measurement device of claim 1, wherein, The voltage adjustment circuit includes a first switch unit, a second switch unit, a first resistor and a second resistor; The control end of the first switch unit and the control end of the second switch unit are respectively connected to the control end of the voltage adjustment circuit, and the first end of the first switch unit and the first end of the second switch unit are respectively connected to the first end of the voltage adjustment circuit; the second end of the first switch unit is connected to the first end of the first resistor, and the second end of the first resistor is connected to the second end of the voltage adjustment circuit; the second end of the second switch unit is connected to the first end of the second resistor, and the second end of the second resistor is connected to the third end of the voltage adjustment circuit.

3. The battery impedance measurement device of claim 2, wherein, The first switch unit includes a first switch tube, a second switch tube and a first inverter, and the second switch unit includes a third switch tube, a fourth switch tube and a second inverter; The input end of the first inverter and the control end of the second switch tube are respectively connected to the control end of the first switch unit, the control end of the first switch tube is connected to the output end of the first inverter, the first end of the first switch tube and the first end of the second switch tube are respectively connected to the first end of the first switch unit, and the second end of the first switch tube and the second end of the second switch tube are respectively connected to the second end of the first switch unit; The input end of the second inverter and the control end of the third switch tube are respectively connected to the control end of the second switch unit, the control end of the fourth switch tube is connected to the output end of the second inverter, the first end of the third switch tube and the first end of the fourth switch tube are respectively connected to the first end of the second switch unit, and the second end of the third switch tube and the second end of the fourth switch tube are respectively connected to the second end of the second switch unit.

4. The battery impedance measurement device of claim 2, wherein, The voltage adjustment circuit further includes a third resistor and a fourth resistor; The first end of the third resistor is connected to the first voltage end, and the second end of the third resistor is connected to the second end of the first resistor; the first end of the fourth resistor is connected to the first voltage end, and the second end of the fourth resistor is connected to the second end of the second resistor.

5. The battery impedance measurement device of claim 1, wherein, The delay detection circuit includes a detection circuit, a trigger, an oscillator and a counter; The positive and negative input terminals of the detection circuit are respectively connected to the positive and negative input terminals of the delay detection circuit, the output terminal of the detection circuit is connected to the input terminal of the trigger, the clock terminal of the trigger is connected to the oscillator, the output terminal of the trigger is connected to the input terminal of the counter, and the output terminal of the counter is connected to the output terminal of the delay detection circuit.

6. The battery impedance measurement device of claim 5, wherein, The detection circuit includes a first comparator, a second comparator, a third comparator, a fourth comparator, a fifth switch tube, a sixth switch tube, a seventh switch tube, an eighth switch tube, a fifth resistor and a sixth resistor; The positive and negative input terminals of the first comparator are respectively connected to the first reference voltage terminal and the negative input terminal of the detection circuit; the output terminal of the first comparator is connected to the control terminal of the fifth switch tube; the first terminal of the fifth switch tube is respectively connected to the first terminal of the fifth resistor and the output terminal of the detection circuit; the second terminal of the fifth resistor is connected to the second voltage terminal; and the second terminal of the fifth switch tube is grounded; The positive and negative input terminals of the second comparator are respectively connected to the negative input terminal of the detection circuit and the second reference voltage terminal, the output terminal of the second comparator is connected to the control terminal of the sixth switch tube, the first terminal of the sixth switch tube is connected to the output terminal of the detection circuit, and the second terminal of the sixth switch tube is grounded; The positive and negative input terminals of the third comparator are respectively connected to the first reference voltage terminal and the positive input terminal of the detection circuit; the output terminal of the third comparator is connected to the control terminal of the seventh switch tube; the first terminal of the seventh switch tube is respectively connected to the first terminal of the sixth resistor and the output terminal of the detection circuit; the second terminal of the sixth resistor is connected to the second voltage terminal; and the second terminal of the seventh switch tube is grounded; The positive and negative input terminals of the fourth comparator are respectively connected to the positive input terminal of the detection circuit and the second reference voltage terminal, the output terminal of the fourth comparator is connected to the control terminal of the eighth switch tube, the first terminal of the eighth switch tube is connected to the output terminal of the detection circuit, and the second terminal of the eighth switch tube is grounded.

7. The battery impedance measurement device of claim 6, wherein, The detection circuit further includes a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor; The seventh resistor is connected between the output end of the first comparator and the control end of the fifth switch tube, the eighth resistor is connected between the output end of the second comparator and the control end of the sixth switch tube, the ninth resistor is connected between the output end of the third comparator and the control end of the seventh switch tube, and the tenth resistor is connected between the output end of the fourth comparator and the control end of the eighth switch tube.

8. The battery impedance measurement device of claim 5, wherein, The delay detection circuit also includes a monostable circuit; The input end of the monostable circuit is connected to the output end of the detection circuit, and the output end of the monostable circuit is connected to the reset end of the counter.

9. The battery impedance measurement device of any one of claims 1-8, wherein, The battery impedance measuring device further comprises an eleventh resistor and a twelfth resistor; The second end of the first coupling capacitor is connected to the second end of the voltage adjustment circuit and the positive input end of the differential amplifier through the eleventh resistor respectively, and the second end of the second coupling capacitor is connected to the third end of the voltage adjustment circuit and the negative input end of the differential amplifier through the twelfth resistor respectively.

10. A battery thermal runaway detection apparatus, comprising: The battery impedance measuring device, the alternating current generator, the positive and negative alternating current output ends, the processor, the temperature and humidity collector, the display screen and the memory are included. The processor is connected to the positive and negative measuring output ends of the battery impedance measuring device, the alternating current generator, the temperature and humidity collector, the display screen and the memory respectively, and the alternating current generator is further connected to the positive and negative alternating current output ends.

Images