CN110370984A - Power battery thermal runaway method for early warning - Google Patents

Abstract

This application provides a power battery thermal runaway early warning method, which calculates the abnormal deviation of the lowest battery cell voltage from the average voltage and calculates the difference between the highest cell temperature and the average temperature through the real-time detection data of the battery cell voltage and battery cell temperature. Exception offset. Detect the battery value of the battery module, and calculate the abnormal shift of the state of charge according to the above-mentioned various detection parameters. Simultaneously detect the combustible gas concentration and gas pressure in real time, and judge whether the combustible gas concentration reaches the threshold and whether the gas pressure reaches the threshold. Considering the above parameters comprehensively, a thermal runaway warning is carried out. Through this method, the thermal runaway can be warned before the thermal runaway occurs, thereby reducing the harm caused by the thermal runaway to a great extent. The application will help to improve the reliability of power battery safety management and reduce the occurrence of lithium-ion power battery safety accidents.

Description

Power battery thermal runaway early warning method

technical field

The present application relates to the field of battery technology, in particular to a thermal runaway warning method for a power battery.

Background technique

In order to alleviate the problems of energy shortage and environmental pollution, my country has listed new energy vehicles as a strategic emerging technology industry. The electrification of automobile power system has gradually become one of the main trends in the development of future automobile technology. One of the main characteristics of the electrification of the vehicle power system is to use electrical energy instead of chemical energy as the main source of driving energy for the vehicle. Due to its high specific energy, low self-discharge rate and long cycle life, lithium-ion power batteries are currently the most practical energy source for pure electric vehicles.

However, with the large-scale application of lithium-ion batteries in electric vehicles, safety accidents of lithium-ion power batteries represented by thermal runaway occur from time to time. Lithium-ion power battery accidents usually manifest as a sudden temperature rise, smoke, fire or even explosion with thermal runaway as the core. Thermal runaway accidents usually release a large amount of energy in a short period of time, which can easily cause casualties and property losses. Therefore, thermal runaway accidents will dampen people's confidence in accepting electric vehicles and hinder the popularization of electric vehicles.

Lithium-ion power battery thermal runaway accidents may be caused by mechanical abuse (extrusion, acupuncture, collision, etc.), electrical abuse (overcharge, overdischarge, internal short circuit, etc.) and thermal abuse. There is a certain internal connection between these three abuses. Mechanical abuse leads to battery deformation, and battery deformation may lead to internal short circuit, that is, electrical abuse, and electrical abuse is often accompanied by Joule heat, which is the heat of chemical reaction, and the accumulation of heat This leads to thermal abuse, and eventually thermal abuse leads to an increase in battery temperature, causing a thermal runaway chain reaction.

Relevant studies have shown that there is currently no absolutely reliable method to avoid the recurrence of thermal runaway and the spread of thermal runaway in the battery system. Therefore, in order to reduce the harm of thermal runaway, it is extremely necessary to make thermal runaway warnings before thermal runaway occurs. The traditional thermal runaway early warning method has low detection accuracy.

Contents of the invention

Based on this, it is necessary to provide a power battery thermal runaway early warning method for the problem of low detection accuracy of the traditional thermal runaway early warning method.

A thermal runaway warning method for a power battery, comprising:

S10, acquire the thermal runaway parameters of the power battery in real time, the thermal runaway parameters include the voltage value and temperature value of each battery cell in the power battery module, and the thermal runaway parameters also include the current of the power battery module value, the concentration of combustible gas and the pressure of gas;

S20. According to each of the voltage values, each of the temperature values, the current value, the concentration of the combustible gas, and the pressure of the gas, respectively obtain a first fault bit, a second fault bit, and a third fault bit, the fourth fault bit and the fifth fault bit;

S30. Obtain a total fault bit according to the first fault bit, the second fault bit, the third fault bit, the fourth fault bit, and the fifth fault bit;

S40, judging whether the total fault bits are greater than or equal to a preset fault bit threshold, and performing a thermal runaway alarm when the total fault bits are greater than or equal to the preset fault bit threshold.

In one of the embodiments, the specific steps of obtaining the fifth fault bit include:

Obtain an average state of charge value and a minimum state of charge value according to the voltage value of each of the battery cells, the temperature value of each of the battery cells, and the current value of the power battery module;

Obtain an actual state of charge difference value according to the average state of charge value and the minimum state of charge value;

The fifth fault bit is obtained according to the actual SOC difference value.

In one of the embodiments, the specific step of obtaining the fifth fault bit according to the actual SOC difference value includes:

Dividing the range of preset state of charge difference values into multiple state of charge reference intervals;

Judging the SOC reference interval to which the actual SOC difference value belongs, and then determining the fifth fault bit.

In one of the embodiments, the specific steps of obtaining the first fault bit include:

Obtaining the average value of the cell voltage and the minimum value of the cell voltage according to the voltage value of each of the battery cells;

Obtain an actual battery cell voltage difference value according to the average value of the cell voltage and the minimum value of the cell voltage;

The first fault bit is obtained according to the actual battery cell voltage difference value.

In one of the embodiments, the specific step of obtaining the first fault bit according to the actual battery cell voltage difference value includes:

Dividing the range of preset battery cell voltage difference values into a plurality of voltage reference intervals;

Judging the voltage reference interval to which the actual battery cell voltage difference value belongs, and then determining the first fault bit.

In one of the embodiments, the specific steps of obtaining the second fault bit include:

The S30, according to the temperature value of each of the battery cells, obtain the average value of the cell temperature and the maximum value of the cell temperature;

Obtain an actual battery cell temperature difference value according to the average cell temperature and the maximum cell temperature;

The second fault bit is obtained according to the actual battery cell temperature difference value.

In one of the embodiments, the specific step of obtaining the second fault bit according to the actual battery cell temperature difference value includes:

Dividing the range of preset battery cell temperature difference values into multiple temperature reference intervals;

Judging the temperature reference interval to which the actual battery cell temperature difference value belongs, and then determining the second fault bit.

In one of the embodiments, the specific steps of obtaining the third fault bit include:

Obtain the actual concentration difference value of the battery module according to the concentration value of the combustible gas at the current moment and the concentration value of the combustible gas at the initial moment;

According to the actual concentration difference value, the third fault bit is obtained.

In one of the embodiments, the specific step of obtaining the third fault bit according to the actual concentration difference value includes:

Divide the range of preset battery module concentration difference values into multiple concentration reference intervals;

Judging the concentration reference interval to which the actual concentration difference value belongs, and then determining the third fault bit.

In one of the embodiments, the specific steps of obtaining the fourth fault bit include:

Obtain the actual pressure difference value of the battery module according to the pressure value of the gas at the current moment and the pressure value of the gas at the initial moment;

The fourth fault bit is obtained according to the actual pressure difference value.

In one of the embodiments, the specific step of obtaining the fourth fault bit according to the actual pressure difference value includes:

Divide the range of preset battery module pressure difference values into multiple pressure reference intervals;

Judging the pressure reference interval to which the actual pressure difference value belongs, and then determining the fourth fault bit.

A computer device, including a memory, a processor, and a computer program stored on the memory and run on the processor, when the processor executes the computer program, the thermal runaway of the power battery described in any one of the above embodiments is realized Steps in the early warning method.

The above-mentioned power battery thermal runaway warning method uses the real-time detection data of battery cell voltage and battery cell temperature to calculate the abnormal deviation of the lowest battery cell voltage from the average voltage, and calculate the abnormal deviation of the highest cell temperature from the average temperature. Detect the battery value of the battery module, and calculate the abnormal shift of the state of charge according to the above-mentioned various detection parameters. Simultaneously detect the combustible gas concentration and gas pressure in real time, and judge whether the combustible gas concentration reaches the threshold and whether the gas pressure reaches the threshold. Considering the above parameters comprehensively, a thermal runaway warning is carried out. Through this method, the thermal runaway can be warned before the thermal runaway occurs, thereby reducing the harm caused by the thermal runaway to a great extent. The application will help to improve the reliability of power battery safety management and reduce the occurrence of lithium-ion power battery safety accidents.

Description of drawings

Fig. 1 is a flowchart of a power battery thermal runaway warning method provided by an embodiment of the present application;

Fig. 2 is a schematic diagram of the calculation of the total fault position and the judgment conditions of the thermal runaway warning provided by one embodiment of the present application;

FIG. 3 is a graph of fault bits and total fault bits of each parameter provided by an embodiment of the present application.

Detailed ways

In order to make the above-mentioned purpose, features and advantages of the present application more obvious and understandable, the specific implementation manners of the present application will be described in detail below in conjunction with the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the application. However, the present application can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific implementation disclosed below.

It should be noted that when an element is referred to as being “disposed on” another element, it may be directly on the other element or there may also be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or intervening elements may also be present.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of the application are only for the purpose of describing specific embodiments, and are not intended to limit the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to FIG. 1 , an embodiment of the present application provides a thermal runaway warning method for a power battery. The power battery thermal runaway warning method includes:

S10, acquire the thermal runaway parameters of the power battery in real time, the thermal runaway parameters include the voltage value and temperature value of each battery cell in the power battery module, and the thermal runaway parameters also include the current of the power battery module value, the concentration of combustible gas and the pressure of gas. In step S10, the power battery may be a lithium-ion power battery. The rated capacity of the lithium-ion power battery may be 25Ah. The above detection parameters can be obtained in real time through various sensors.

S20. According to each of the voltage values, each of the temperature values, the current value, the concentration of the combustible gas, and the pressure of the gas, respectively obtain a first fault bit, a second fault bit, and a third fault bit, the fourth fault bit, and the fifth fault bit. Specifically, the average value of the cell voltage and the minimum value of the cell voltage can be obtained according to the voltage value of each of the battery cells, and the first fault bit can be obtained according to the average value of the cell voltage and the minimum value of the cell voltage . The processor can sort the cell voltage values of all the battery cells in the battery module at the same time, and calculate the average voltage at the current time. The first fault bit can be 0, 1 or 2. The larger the value of the fault bit, the more likely thermal runaway will occur.

Specifically, according to the temperature value of each of the battery cells, an average value of the cell temperature and a maximum value of the cell temperature are obtained, and a second fault bit is obtained according to the average value of the cell temperature and the maximum value of the cell temperature. The processor can sort the temperature values of all the battery cells in the battery module at the same time, and calculate the average temperature at the current time. The second fault bit can be 0, 1 or 2. The larger the value of the fault bit, the more likely thermal runaway will occur.

Specifically, the third fault bit is obtained according to the real-time concentration value of the combustible gas of the power battery module. Before thermal runaway occurs, the concentration value of the combustible gas will increase sharply, so the value of the difference of the combustible gas concentration can be judged by the processor, and then the value of the third fault bit can be determined. The third fault bit can be 0 or 1.

Specifically, the fourth fault bit is obtained according to the real-time pressure value of the gas of the power battery module. Before thermal runaway occurs, the pressure value of the gas will increase sharply, so the value of the fourth fault bit can be determined by judging the difference value of the gas pressure by the processor. The fourth fault bit can be 0 or 1.

Specifically, according to the voltage value of each of the battery cells, the temperature value of each of the battery cells and the current value of the power battery module, the average state of charge value and the minimum state of charge value are obtained, according to The average SOC value and the minimum SOC value obtain a fifth fault bit. Estimating the state of charge based on the model, using the lowest voltage V and the highest temperature T _max,k of each battery cell to estimate the minimum state of charge value SOC _min,k , using the average voltage VV of the remaining batteries except V to remove T The average temperature V of the remaining batteries in _{max, k} is estimated to be the average state of charge value V. The fifth fault bit can be 0, 1 or 2.

S30. Obtain a total fault bit according to the first fault bit, the second fault bit, the third fault bit, the fourth fault bit, and the fifth fault bit. In step S30, after the value of each fault bit is respectively determined by the processor, the value of the total fault bit may be calculated by an adder, as shown in FIG. 2 .

S40, judging whether the total fault bits are greater than or equal to a preset fault bit threshold, and performing a thermal runaway alarm when the total fault bits are greater than or equal to the preset fault bit threshold. In step S40, the preset fault threshold can be set through multiple trials. In an optional embodiment, the preset fault bit threshold may be 5, as shown in FIG. 3 .

In this embodiment, based on the real-time detection data of battery cell voltage and battery cell temperature, the abnormal deviation of the lowest battery cell voltage from the average voltage is calculated, and the abnormal deviation of the highest battery cell temperature from the average temperature is calculated. Detect the battery value of the battery module, and calculate the abnormal shift of the state of charge according to the above-mentioned various detection parameters. Simultaneously detect the combustible gas concentration and gas pressure in real time, and judge whether the combustible gas concentration reaches the threshold and whether the gas pressure reaches the threshold. Considering the above parameters comprehensively, a thermal runaway warning is carried out. Through this method, the thermal runaway can be warned before the thermal runaway occurs, thereby reducing the harm caused by the thermal runaway to a great extent. The application will help to improve the reliability of power battery safety management and reduce the occurrence of lithium-ion power battery safety accidents.

In one embodiment, according to the voltage value of each of the battery cells, the temperature value of each of the battery cells and the current value of the power battery module, the average state of charge value and the minimum state of charge are obtained value, the specific steps of obtaining the fifth fault bit according to the average SOC value and the minimum SOC value include:

According to the average state of charge value and the minimum state of charge value, an actual state of charge difference value is obtained. The range of the preset SOC difference value is divided into a plurality of SOC reference intervals, and each SOC reference interval is correspondingly set with a fifth fault bit value. Judging the SOC reference interval to which the actual SOC difference value belongs, and then determining the fifth fault bit.

One or more of the extended Kalman filter estimation SOC algorithm, unscented Kalman filter estimation SOC algorithm, adaptive filter estimation SOC algorithm, synovial film observer estimation SOC algorithm, open circuit voltage look-up table method or other SOC estimation methods can be used. and obtaining the average SOC value and the minimum SOC value. The average SOC value and the minimum SOC value may also be obtained by using a first-order RC equivalent circuit model and a Kalman filter fusion algorithm.

The number of the state of charge reference intervals may be three, the value of the fifth fault bit set corresponding to the first state of charge reference interval is 0, and the value of the fifth fault bit set corresponding to the second state of charge reference interval The value of the bit is 1, and the value of the fifth fault bit set corresponding to the third state of charge reference interval is 2. In an optional embodiment, the first reference interval of the state of charge is [0%, 10%). The second state of charge reference interval is [10%, 20%). The third SOC reference interval is [20%, +∞). When the actual SOC difference is greater than 10%, the fifth fault bit jumps from 0 to 1. When the actual SOC difference is greater than 20%, the fifth fault bit jumps from 1 to 2.

In one embodiment, according to the voltage value of each of the battery cells, the average value of the cell voltage and the minimum value of the cell voltage are obtained, and the first cell voltage is obtained according to the average value of the cell voltage and the minimum value of the cell voltage. The specific steps for fault bits include:

According to the average value of the cell voltage and the minimum value of the cell voltage, an actual battery cell voltage difference value is obtained. Divide the range of preset battery cell voltage difference values into a plurality of voltage reference intervals, and each voltage reference interval corresponds to setting a value of the first fault bit. Judging the voltage reference interval to which the actual battery cell voltage difference value belongs, and then determining the first fault bit.

The number of the voltage reference intervals may be three. The value of the first fault bit set corresponding to the first voltage reference interval is 0, the value of the first fault bit set corresponding to the second voltage reference interval is 1, and the value of the first fault bit set corresponding to the third voltage reference interval The fault bit has a value of 2. In an optional embodiment, the first voltage reference interval is [0V, 0.1V). The second voltage reference interval is [0.1V, 5V). The third voltage reference interval is [5V, +∞). When the actual battery cell voltage difference is greater than 0.1V, the first fault bit jumps from 0 to 1. When the actual battery cell voltage difference is greater than 5V, the first fault bit jumps from 1 to 2.

In one embodiment, according to the temperature value of each of the battery cells, the average value of the cell temperature and the maximum value of the cell temperature are obtained, and according to the average value of the cell temperature and the maximum value of the cell temperature, the The specific steps of the second fault bit include:

According to the average cell temperature and the maximum cell temperature, an actual battery cell temperature difference value is obtained. Divide the range of preset battery cell temperature difference values into a plurality of temperature reference intervals, and each temperature reference interval corresponds to setting a value of a second fault bit. Judging the temperature reference interval to which the actual battery cell temperature difference value belongs, and then determining the second fault bit.

The number of the temperature reference intervals may be three, the value of the second fault bit set corresponding to the first temperature reference interval is 0, the value of the second fault bit set corresponding to the second temperature reference interval is 1, The value of the second fault bit set corresponding to the third temperature reference interval is 2. In an optional embodiment, the first temperature reference range is [0°C, 5°C). The second temperature reference interval is [5°C, 10°C). The third temperature reference range is [10°C, +∞). When the actual battery cell temperature difference is greater than 5° C., the second fault bit jumps from 0 to 1. When the actual battery cell temperature difference is greater than 10° C., the second fault bit jumps from 1 to 2.

In one embodiment, the specific steps of obtaining the third fault bit according to the real-time concentration value of the combustible gas of the power battery module include:

The actual concentration difference value of the battery module is obtained according to the concentration value of the combustible gas at the current moment and the concentration value of the combustible gas at the initial moment. The range of the preset battery module concentration difference value is divided into a plurality of concentration reference intervals, and each concentration reference interval corresponds to setting a value of a third fault bit. Judging the concentration reference interval to which the actual concentration difference value belongs, and then determining the third fault bit. The concentration value of the combustible gas at the initial moment may be the concentration value of the combustible gas at the detection start moment. The concentration value of the combustible gas at the initial moment may also be the concentration value of the combustible gas at a previous moment arbitrarily set by the processor.

The number of the concentration reference intervals may be two, the value of the third fault bit set corresponding to the first concentration reference interval is 0, and the value of the third fault bit set corresponding to the second concentration reference interval is 1. It should be pointed out here that the sensor for detecting the concentration of combustible gas may be a gas sensor. The gas sensor may be a semiconductor gas sensor. The working principle of the gas sensor is that as the concentration of the gas to be detected increases, the resistance of the semiconductor will change. The semiconductor is connected in series with a fixed value resistor, and the concentration of the gas to be measured can be detected by measuring the voltage at both ends of the semiconductor. . Therefore, the voltage value detected by the gas sensor can reflect the concentration value of the combustible gas. In an optional embodiment, the first concentration reference range is [0V, 1V). The second concentration reference interval is [1V,+∞). When the actual concentration difference value is greater than 1V, the third fault bit jumps from 0 to 1.

In one embodiment, the specific steps of obtaining the fourth fault bit according to the real-time pressure value of the gas of the power battery module include:

According to the pressure value of the gas at the current moment and the pressure value of the gas at the initial moment, the actual pressure difference value of the battery module is obtained. The range of the preset pressure difference value of the battery module is divided into a plurality of pressure reference intervals, and each pressure reference interval corresponds to setting a value of the fourth fault bit. Judging the pressure reference interval to which the actual pressure difference value belongs, and then determining the fourth fault bit. The pressure value of the gas at the initial moment may be the pressure value of the gas at the beginning moment of detection. The pressure value of the gas at the initial moment may also be the pressure value of the gas at a previous moment arbitrarily set by the processor.

Table 1. Determination conditions for each parameter threshold value and each parameter fault bit

The number of the pressure reference intervals is two, the value of the fourth fault bit set corresponding to the first pressure reference interval is 0, and the value of the fourth fault bit set corresponding to the second pressure reference interval is 1. In an optional embodiment, the first pressure reference range is [0KPa, 10KPa). The second pressure reference interval is [10KPa, +∞). When the actual pressure difference is greater than 10KPa, the fourth fault bit jumps from 0 to 1. The determination conditions of each parameter threshold and each parameter fault bit provided by an embodiment of the present application are shown in Table 1 below.

A computer device, including a memory, a processor, and a computer program stored on the memory and run on the processor, when the processor executes the computer program, the thermal runaway of the power battery described in any one of the above embodiments is realized Steps in the early warning method.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is relatively specific and detailed, but should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of protection of the patent application should be based on the appended claims.

Claims (12)

1. a kind of power battery thermal runaway method for early warning characterized by comprising

S10 obtains the thermal runaway parameter of power battery in real time, and the thermal runaway parameter includes each of power battery module The voltage value and temperature value of battery cell, the thermal runaway parameter further include the current value of the power battery module, combustible gas The concentration of body and the pressure of gas；

S20, according to the concentration of voltage value described in each, each described temperature value, the current value, the fuel gas with And the pressure of the gas, Fisrt fault position, the second fault bit, third fault bit, the 4th fault bit and the 5th are obtained respectively Fault bit；

S30, according to the Fisrt fault position, second fault bit, the third fault bit, the 4th fault bit and institute It states the 5th fault bit and obtains total failare position；

S40, judges whether the total failare position is greater than or equal to preset failure position threshold value, when the total failare position is greater than or equal to When the preset failure position threshold value, thermal runaway alarm is carried out.

2. power battery thermal runaway method for early warning according to claim 1, which is characterized in that obtain the 5th fault bit Specific steps include:

According to the voltage value of battery cell described in each, the temperature value and the power battery of each battery cell The current value of mould group obtains average state of charge and minimum state of charge；

According to the average state of charge and the minimum state of charge, practical charge state difference value is obtained；

According to the practical charge state difference value, the 5th fault bit is obtained.

3. power battery thermal runaway method for early warning according to claim 2, which is characterized in that described according to the practical lotus Electricity condition difference value, the specific steps for obtaining the 5th fault bit include:

The range of default charge state difference value is divided into multiple state-of-charge reference intervals；

Judge state-of-charge reference interval belonging to the practical charge state difference value, and then determines the 5th fault bit.

4. power battery thermal runaway method for early warning according to claim 1, which is characterized in that obtain the Fisrt fault position Specific steps include:

According to the voltage value of battery cell described in each, monomer voltage average value and monomer voltage minimum value are obtained；

According to the monomer voltage average value and the monomer voltage minimum value, actual battery monomer voltage difference value is obtained；

According to the actual battery monomer voltage difference value, the Fisrt fault position is obtained.

5. power battery thermal runaway method for early warning according to claim 4, which is characterized in that described according to the practical electricity Pond monomer voltage difference value, the specific steps for obtaining the Fisrt fault position include:

The range of default battery cell voltage difference value is divided into multiple Voltage Reference sections；

Judge Voltage Reference section belonging to the actual battery monomer voltage difference value, and then determines the Fisrt fault position.

6. power battery thermal runaway method for early warning according to claim 1, which is characterized in that obtain second fault bit Specific steps include:

The S30 obtains monomer temperature average value and monomer temperature is maximum according to the temperature value of battery cell described in each Value；

According to the monomer temperature average value and the monomer temperature maximum value, actual battery monomer temperature difference value is obtained；

According to the actual battery monomer temperature difference value, second fault bit is obtained.

7. power battery thermal runaway method for early warning according to claim 6, which is characterized in that described according to the practical electricity Pond monomer temperature difference value, the specific steps for obtaining second fault bit include:

The range of default battery cell temperature difference value is divided into multiple temperature reference sections；

Judge temperature reference section belonging to the actual battery monomer temperature difference value, and then determines second fault bit.

8. power battery thermal runaway method for early warning according to claim 1, which is characterized in that obtain the third fault bit Specific steps include:

According to the concentration value of the concentration value of current time fuel gas and initial time fuel gas, the battery modules are obtained Actual concentrations difference value；

According to the actual concentrations difference value, the third fault bit is obtained.

9. power battery thermal runaway method for early warning according to claim 8, which is characterized in that described dense according to the reality Difference value is spent, the specific steps for obtaining the third fault bit include:

The range of default battery modules concentration difference value is divided into multiple concentration reference intervals；

Judge concentration reference interval belonging to the actual concentrations difference value, and then determines the third fault bit.

10. power battery thermal runaway method for early warning according to claim 1, which is characterized in that obtain the 4th failure Position specific steps include:

According to the pressure value of the pressure value of current time gas and initial time gas, the actual pressure of the battery modules is obtained Difference value；

According to the actual pressure difference value, the 4th fault bit is obtained.

11. power battery thermal runaway method for early warning according to claim 10, which is characterized in that described according to the reality Pressure gap value, the specific steps for obtaining the 4th fault bit include:

The range of default battery modules pressure gap value is divided into multiple pressure reference sections；

Judge pressure reference section belonging to the actual pressure difference value, and then determines the 4th fault bit.

12. a kind of computer equipment, the calculating run on a memory and on a processor including memory, processor and storage Machine program, which is characterized in that the processor is realized described in any one of claims 1 to 11 when executing the computer program Power battery thermal runaway method for early warning the step of.