CN114454774A - Battery pack thermal runaway early warning system and method - Google Patents

The invention provides a battery pack thermal runaway early warning system and method, wherein the battery pack thermal runaway early warning method comprises the following steps: collecting thermal runaway related information of a battery pack; carrying out data transmission on the thermal runaway correlation information so that a whole vehicle control system can acquire the thermal runaway correlation information; acquiring historical thermal runaway correlation information before transmission failure of the thermal runaway correlation information, and performing thermal runaway early warning on the battery pack according to the historical thermal runaway correlation information when the historical thermal runaway correlation information is matched with a preset first early warning threshold; the reliability and the accuracy of the early warning of the thermal runaway of the battery pack are improved, and therefore the potential safety hazard of the thermal runaway of the battery pack of the electric automobile is reduced.

Battery pack thermal runaway early warning system and method

Technical Field

The application relates to the technical field of thermal runaway management of battery packs, in particular to a thermal runaway early warning system and method for a battery pack.

Background

With the rapid development of new energy vehicles and the reduction of environmental pollution caused by fuel vehicles, the motorization of vehicle power systems has gradually become the mainstream development trend, and meanwhile, power batteries for storing vehicle driving energy belong to the core research and development direction of new energy vehicles.

At present, the most popular lithium ion battery has the characteristics of high energy, low self-discharge rate and long cycle life, but along with the market introduction of more and more new energy automobiles, the safety accidents of the lithium ion power battery represented by thermal runaway sometimes occur, and therefore, the thermal runaway early warning about the power battery becomes the necessary and effective safety guarantee for the power battery.

The detection method of the power battery system in the prior art when thermal runaway occurs is that detection and early warning are carried out by a battery management system and a thermal runaway detection system, fault early warning when the battery management system or the thermal runaway detection system fails cannot be avoided, certain potential safety hazards still exist, and further the life safety of passengers is threatened.

Disclosure of Invention

The invention provides a battery pack thermal runaway early warning system and method, which aim to improve the reliability and accuracy of battery pack thermal runaway early warning and further reduce the potential safety hazard of thermal runaway of a battery pack of an electric vehicle.

In order to achieve the purpose, the specific technical scheme of the battery pack thermal runaway early warning system and method is as follows:

in a first aspect, a battery pack thermal runaway early warning method includes the following steps:

collecting thermal runaway related information of the battery pack;

carrying out data transmission on the thermal runaway associated information so that a vehicle control system can acquire the thermal runaway associated information;

acquiring historical thermal runaway associated information before transmission failure of the thermal runaway associated information, and performing thermal runaway early warning on the battery pack according to the historical thermal runaway associated information when the historical thermal runaway associated information is matched with a preset first early warning threshold.

Optionally, the historical thermal runaway associated information within a first preset time is obtained, and when the historical thermal runaway associated information within the first preset time matches a preset first early warning threshold, the thermal runaway early warning of the battery pack is performed according to the historical thermal runaway associated information.

Optionally, the historical thermal runaway correlation information includes a temperature of the battery pack and a voltage of the battery pack;

the first early warning threshold value comprises a temperature early warning threshold value of the battery pack and a voltage early warning threshold value of the battery pack;

and when the temperature of the battery pack is higher than a first early warning threshold value and/or the voltage of the battery pack is lower than the first early warning threshold value, determining that a thermal runaway early warning fault occurs.

Optionally, matching the collected thermal runaway correlation information with a preset second early warning threshold;

and when the thermal runaway associated information is matched with the second early warning threshold value and the transmission of the thermal runaway associated information is successful, confirming that the thermal runaway condition of the battery pack is established, and performing thermal runaway early warning on the battery pack according to the thermal runaway associated information.

Optionally, the temperature of a plurality of detection modules for detecting the battery pack and the temperature rise rate of the detection modules are obtained;

the second early warning threshold comprises a plurality of temperature early warning thresholds of the detection modules and a temperature rise rate early warning threshold of the detection modules;

when the temperature of at least two detection modules is matched with the second early warning threshold value, the temperature rise rate of the detection modules is matched with the second early warning threshold value and lasts for second preset time, the condition of thermal runaway of the battery pack is met.

Optionally, the smoke concentration outside the battery pack is obtained;

the second early warning threshold comprises a smoke concentration early warning threshold outside the battery pack;

and when the smoke concentration outside the battery pack is matched with the second early warning threshold value and lasts for a third preset time, the condition of thermal runaway of the battery pack is met.

Optionally, the temperature outside the battery pack, the temperature rise rate outside the battery pack, and the voltage inside the battery pack are obtained;

the second early warning threshold value comprises a temperature early warning threshold value outside the battery pack, a temperature rise rate early warning threshold value outside the battery pack and a voltage early warning threshold value inside the battery pack;

and when the temperature outside the battery pack, the temperature rise rate outside the battery pack and the voltage inside the battery pack are respectively matched with the second early warning threshold value and last for a fourth preset time, the condition of thermal runaway of the battery pack is met.

Optionally, the temperature inside the battery pack, the temperature rise rate inside the battery pack, and the voltage inside the battery pack are obtained;

the second early warning threshold value comprises a temperature early warning threshold value inside the battery pack, a temperature rise rate early warning threshold value inside the battery pack and a voltage early warning threshold value inside the battery pack;

and when the temperature inside the battery pack, the temperature rise rate inside the battery pack and the voltage inside the battery pack are respectively matched with the second early warning threshold value and last for a fifth preset time, the condition of thermal runaway of the battery pack is met.

Optionally, the power-on step before the battery pack is used includes:

presetting a normal voltage threshold of the battery pack, and carrying out abnormity detection on the battery pack before the battery pack is electrified;

acquiring a power-off request of the battery pack according to the abnormal data of the battery pack, and performing data transmission on the power-off request so that the whole vehicle control system acquires the power-off request;

when the whole vehicle control system obtains the power-off request, the whole vehicle control system controls the battery pack to power off.

In a second aspect, a battery pack thermal runaway early warning system includes:

the thermal runaway detection unit is used for acquiring thermal runaway associated information;

the data transmission unit is used for data transmission of the thermal runaway related information and is electrically connected with the thermal runaway detection unit;

and the thermal runaway early warning unit is electrically connected with the data transmission unit and is used for carrying out thermal runaway early warning on the battery pack according to the thermal runaway related information.

The battery pack thermal runaway early warning method at least has the following advantages: when the battery thermal runaway detection fails or fails, the whole vehicle control system cannot acquire thermal runaway associated information through data transmission, and executes thermal runaway early warning when the battery pack is determined to be thermally runaway according to the historical thermal runaway associated information by acquiring the historical thermal runaway associated information, so that the use safety and reliability of the thermal runaway early warning system are improved.

Drawings

Fig. 1 is a schematic diagram illustrating a connection relationship between a plurality of execution units in a thermal runaway early warning system for a battery pack according to an embodiment of the present disclosure;

FIG. 2 is a schematic main flow chart of a thermal runaway warning method for a battery pack according to an embodiment of the present application;

FIG. 3 is a flow chart of a method for warning of thermal runaway in a battery pack in one embodiment of the present application;

FIG. 4 is a flow chart of a method for warning of thermal runaway in a battery pack in another embodiment of the present application;

FIG. 5 is a flowchart illustrating a thermal runaway determination condition of a battery pack thermal runaway warning method in an embodiment of the present application;

FIG. 6 is a schematic main flow chart of a method for detecting power-on of a battery pack according to an embodiment of the present application;

FIG. 7 is a schematic diagram of the overall structure of a thermal runaway early warning system for a battery pack according to an embodiment of the present application;

fig. 8 is an overall flowchart of a battery pack thermal runaway warning method in the embodiment of the present application.

Detailed Description

The exemplary embodiments described herein are to be considered in all respects as illustrative and not restrictive, for the purposes of better understanding the objects, structure and function of the invention. Descriptions of features or aspects within each exemplary embodiment should generally be considered as available for similar features or aspects in other exemplary embodiments.

In the mainstream prior art, battery pack thermal runaway early warning system and method about new energy automobile, mainly detect through the sensor, judge whether battery pack appears battery thermal runaway according to the testing result of sensor again, but come into the market along with more and more new energy automobile, because different road conditions, and different driving environment, can lead to sensor detection inefficacy or testing result inaccurate often, thereby there is the potential safety hazard, the incident appears even, in order to improve the safety in utilization of battery pack, this application provides a battery pack thermal runaway early warning system and method, can improve battery pack thermal runaway detection's reliability.

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The application provides a battery package thermal runaway early warning system and method, as shown in fig. 1, the battery package thermal runaway early warning system includes: the thermal runaway detection unit is used for acquiring thermal runaway associated information; the data transmission unit is used for data transmission of the thermal runaway related information and is electrically connected with the thermal runaway detection unit; and the thermal runaway early warning unit is electrically connected with the data transmission unit and is used for carrying out thermal runaway early warning on the battery pack according to the thermal runaway related information.

The method comprises the steps that thermal runaway related information of a battery pack is collected through a thermal runaway detection unit, wherein the thermal runaway detection unit comprises a plurality of detection modules, and the detection modules respectively collect various data of the battery pack, such as temperature, temperature rise rate, voltage and smoke concentration; the data transmission unit is used for transmitting the data detected by the thermal runaway detection unit, and can be a vehicle body bus; and transmitting the thermal runaway associated information to a thermal runaway early warning unit through a vehicle body bus, analyzing the thermal runaway associated information through the thermal runaway early warning unit, and executing corresponding thermal runaway early warning according to an analysis result.

As shown in fig. 2 and 3, the method for warning the thermal runaway of the battery pack comprises the following steps:

s1, collecting thermal runaway related information of the battery pack;

s2, carrying out data transmission on the thermal runaway associated information so that a vehicle control system can acquire the thermal runaway associated information;

s3, obtaining historical thermal runaway related information before transmission failure of the thermal runaway related information, and when the historical thermal runaway related information is matched with a preset first early warning threshold, carrying out thermal runaway early warning on the battery pack according to the historical thermal runaway related information.

Transmitting the collected thermal runaway associated information to a vehicle control system through the steps; if the whole vehicle control system fails to acquire the thermal runaway associated information, the whole vehicle control system intervenes in the auxiliary early warning system and reads historical thermal runaway associated information, wherein the thermal runaway associated information before the data acquisition failure of the whole vehicle control system is used as historical thermal runaway associated information; presetting a first early warning threshold, matching historical associated information with the first early warning threshold, if the historical associated information is matched with the first early warning threshold, confirming that a thermal runaway fault exists, and controlling a related module through a vehicle control system to perform corresponding thermal runaway early warning; by the method, when the thermal runaway detection of the battery pack fails or the data transmission fails, the thermal runaway early warning can be carried out, so that potential safety hazards caused by the thermal runaway of the battery pack are reduced.

When the battery pack warning system is used, the historical thermal runaway related information within first preset time is obtained, for example, the thermal runaway related information within 30 seconds before communication failure is obtained, and when the historical thermal runaway related information within the first preset time is matched with a preset first warning threshold value, thermal runaway warning of the battery pack is conducted according to the historical thermal runaway related information.

In order to improve the reliability of the thermal runaway early warning, historical thermal runaway relevance and a first early warning threshold are matched within first preset time by acquiring historical thermal runaway relevance information within the first preset time, for example, when the temperature of a battery pack is too high, thermal runaway early warning can be triggered, and abnormal conditions that the temperature of the battery pack is too high and the temperature is detected normally may occur at a certain time point.

The thermal runaway associated information comprises the temperature and the voltage of a battery pack, a first early warning threshold comprises a low-voltage early warning value of the battery pack and a high-temperature early warning value of the battery pack, in the thermal runaway detection, the acquired thermal runaway associated information is transmitted to a vehicle control system through a vehicle body bus through a battery management system, if the thermal runaway detection fails, the data transmission of the thermal runaway detection cannot be normally communicated, when the vehicle control system detects that the communication is lost, battery pack voltage data and battery pack temperature data in a period before the communication is lost are acquired, when the voltage data of the battery pack is lower than the first early warning threshold and/or the temperature data of the battery pack is higher than the first early warning threshold, the condition that the thermal runaway fails is met, and the thermal runaway early warning is triggered, so that the reliability of the thermal runaway early warning is improved.

In order to further improve the reliability of the warning of the thermal runaway, as shown in fig. 4, the warning method of the thermal runaway exemplarily illustrates that the warning method of the thermal runaway further includes matching the collected thermal runaway related information with a preset second warning threshold; and when the thermal runaway associated information is matched with the second early warning threshold value and the transmission of the thermal runaway associated information is successful, confirming that the thermal runaway condition of the battery pack is established, and performing thermal runaway early warning on the battery pack according to the thermal runaway associated information. For convenience of understanding, it should be noted that, in the drawing, the thermal runaway detection and the battery management system are in a communication relationship, and the battery management system and the vehicle control system are also in a communication relationship.

The second early warning threshold includes an abnormal voltage value, an abnormal temperature, an abnormal smoke concentration outside the battery pack, and the like of the battery pack, as shown in fig. 5, it is exemplarily illustrated that when the thermal runaway detection is in a normal state and the thermal runaway related information of the battery pack can be normally transmitted to the entire vehicle control system, the detected thermal runaway related information is matched with the second early warning threshold, the battery management system transmits a matching result to the entire vehicle control system, if the matching result is successful, the entire vehicle control system performs corresponding thermal runaway early warning by controlling the thermal runaway early warning related facility, and if the matching result is failed, it is indicated that the thermal runaway does not occur in the battery pack.

Specifically, the second early warning threshold comprises a plurality of early warning conditions, the first early warning condition is the abnormal temperature of the detection module and the abnormal temperature rise rate of the detection module, and the temperature of the detection module and the temperature rise rate of the detection module used for detecting the battery pack are obtained; the second early warning threshold comprises a plurality of temperature early warning thresholds of the detection modules and a temperature rise rate early warning threshold of the detection modules; when the temperature of at least two detection modules is matched with the second early warning threshold value, the temperature rise rate of the detection modules is matched with the second early warning threshold value and lasts for second preset time, the thermal runaway condition of the battery pack is established.

In the actual use process, the detection modules for detecting various thermal runaway related signals generate heat after being used for a long time, so that the detection data is inaccurate or the detection data is lost, therefore, each detection module is provided with a temperature detection module, the temperature of the detection module is monitored while the battery pack is detected, illustratively, when the self temperature values of at least two detection modules reach 75 ℃ and the temperature rise rate is more than 0.5 ℃ per second, the standard of thermal runaway early warning of the battery pack is reached, meanwhile, in order to reduce misjudgment caused by data burst, when the self temperature values of at least two detection modules are matched with the temperature early warning threshold set by the second early warning threshold and last for more than 5 seconds, the condition of thermal runaway early warning is met, and the thermal runaway related facilities are controlled by the control system to execute the thermal runaway early warning, thereby improving the accuracy of the thermal runaway early warning.

The second early warning condition is the abnormal smoke concentration outside the battery pack, and the smoke concentration outside the battery pack is obtained; the second early warning threshold comprises a smoke concentration early warning threshold outside the battery pack; and when the smoke concentration outside the battery pack is matched with the second early warning threshold value and lasts for a third preset time, the thermal runaway condition of the battery pack is met.

The detection module for detecting the smoke detects the smoke concentration outside the battery pack, exemplarily shows that when the detected smoke concentration value reaches 500 micrograms per cubic meter and lasts for more than 3 seconds, the thermal runaway early warning condition is met, and the whole vehicle control system controls the thermal runaway related facility to execute the thermal runaway early warning.

The third early warning condition is the combination of the abnormal temperature outside the battery pack, the abnormal temperature rise rate outside the battery pack and the abnormal voltage inside the battery pack, and the temperature outside the battery pack, the temperature rise rate outside the battery pack and the voltage inside the battery pack are obtained; the second early warning threshold value comprises a temperature early warning threshold value outside the battery pack, a temperature rise rate early warning threshold value outside the battery pack and a voltage early warning threshold value inside the battery pack; and when the temperature outside the battery pack, the temperature rise rate outside the battery pack and the voltage inside the battery pack are respectively matched with the second early warning threshold value and last for a fourth preset time, the thermal runaway condition of the battery pack is met.

The outside temperature of battery package is detected to the detection module through battery package outside temperature and the inside voltage detection module of battery package, the outside temperature rise rate and the internal voltage of battery package detect, exemplarily explain, when the air temperature in the battery package outside that detects is greater than 75 degrees centigrade, the temperature rise rate of battery package outside air is greater than 5 degrees centigrade per second, and simultaneously, the battery package internal voltage that detects is less than 1 when volt, and last more than 3 seconds, satisfy the condition of thermal runaway early warning promptly, and carry out the thermal runaway early warning through whole car control system control thermal runaway associated facility.

The fourth early warning condition is the combination of abnormal temperature inside the battery pack, abnormal temperature rise rate inside the battery pack and abnormal voltage inside the battery pack, and the temperature inside the battery pack, the temperature rise rate inside the battery pack and the voltage inside the battery pack are obtained; the second early warning threshold value comprises a temperature early warning threshold value inside the battery pack, a temperature rise rate early warning threshold value inside the battery pack and a voltage early warning threshold value inside the battery pack; and when the temperature inside the battery pack, the temperature rise rate inside the battery pack and the voltage inside the battery pack are respectively matched with the second early warning threshold value and last for a fourth preset time, the thermal runaway condition of the battery pack is met.

The internal temperature of battery package is detected through the detection module of the internal temperature of battery package and the inside voltage detection module of battery package, the inside temperature rise rate and the internal voltage of battery package detect, exemplarily explain, be greater than 65 degrees centigrade when the battery package internal temperature that detects, the inside temperature rise rate of battery package is greater than 1 degree centigrade per second, and simultaneously, the battery package internal voltage that detects is less than 1 when volt, and last more than 5 seconds, satisfy the condition of thermal runaway early warning promptly, and carry out the thermal runaway early warning through whole car control system control thermal runaway associated facility.

Through the arrangement of the multiple thermal runaway pre-alarms, in the process of thermal runaway detection of the battery pack, the thermal runaway pre-alarm can be triggered as long as one pre-alarm condition is met, so that the accuracy of the thermal runaway pre-alarm is improved, and the probability of missing report in the thermal runaway detection of the battery pack is reduced; meanwhile, the temperature of the detection module body is detected, the early warning condition is set, and when the detection module fails or is detected abnormally, the early warning can still be performed through the thermal runaway early warning unit, so that the maintenance of the thermal runaway early warning unit by workers is facilitated, and the safety and the maintenance convenience of the thermal runaway early warning system of the battery pack are improved.

In order to further improve the safety of the battery pack thermal runaway warning system, as shown in fig. 6, the power-up step before the use of the battery pack includes:

s01, presetting a normal voltage threshold of the battery pack, and carrying out abnormity detection on the battery pack before the battery pack is electrified;

s02, acquiring a power-off request of the battery pack according to the abnormal data of the battery pack, and performing data transmission on the power-off request so that the whole vehicle control system acquires the power-off request;

and S03, when the whole vehicle control system acquires the power-off request, controlling the battery pack to power off through the whole vehicle control system.

Through the power-on step of the battery pack, the battery pack is subjected to self-checking before the battery pack is powered on, specifically, the voltage of the battery pack is detected before the battery pack is powered on at a high voltage, a detection result is transmitted to a battery management system, the battery pack is powered on when the voltage of the battery pack is in a normal state, the battery management system transmits the voltage abnormity information of the battery pack to a whole vehicle control system when the voltage of the battery pack is in an abnormal state, and the whole vehicle control system controls the battery pack to be powered off; if the battery pack is abnormal, the probability of the battery pack breaking down is reduced in a battery pack self-checking mode, and therefore the use safety of the battery pack heat loss early warning system is improved.

The thermal runaway early warning unit comprises a vehicle body controller, a combination instrument and a vehicle network terminal, wherein as shown in fig. 7, the vehicle body controller is electrically connected with a door lock switch of a vehicle door, the vehicle body controller is also electrically connected with an alarm lamp arranged in the vehicle, and the vehicle network terminal is in communication connection with a mobile device, such as a mobile phone end; each thermal runaway early warning unit is in communication connection with a vehicle body bus, and a vehicle controller in a vehicle control system is also in communication connection with the vehicle body bus. Illustratively, when the battery pack is out of control due to heat, the vehicle control unit transmits a data signal for warning due to heat out of control to the vehicle body controller, the vehicle body controller controls the alarm lamp to be turned on, and the vehicle body controls the door lock of the vehicle door to be opened, so that passengers can timely acquire information about the heat out of control due to the heat of the battery pack and can timely leave the vehicle; meanwhile, the thermal runaway early warning information is sent to the mobile equipment through the vehicle-mounted network terminal, and passengers in the vehicle are further prompted through the mobile equipment, so that the use safety of the thermal runaway early warning system is improved.

In order to show the specific content of the present invention more clearly, as shown in fig. 8, the battery pack thermal runaway early warning system and method of the present invention mainly include the following contents:

after the battery pack is electrified at high voltage, real-time detection is carried out through a thermal runaway detection unit, detected thermal runaway relevant information is transmitted to a battery management system, the battery management system matches the thermal runaway relevant information with a second early warning threshold value, and the thermal runaway relevant information and a matching result are transmitted to a whole vehicle control system through a vehicle body bus; when the communication between the battery control system and the whole vehicle control system is normal, the whole vehicle control system executes corresponding thermal runaway early warning control according to the matching result of the thermal runaway correlation information and the second early warning threshold; when the communication between the battery control system and the whole vehicle control system is abnormal, the whole vehicle control system matches the historical thermal runaway correlation information with a first early warning threshold value, and executes corresponding thermal runaway early warning control according to the matching result of the historical thermal runaway correlation information and the first early warning threshold value; the following objects are achieved thereby: under the normal state of the thermal runaway detection of the battery pack, the whole vehicle control system controls the starting of the associated facilities of the thermal runaway early warning according to the acquired thermal runaway associated information; and under the condition that the thermal runaway detection is abnormal or even fails, reading historical thermal runaway related data to judge whether the thermal runaway of the battery pack occurs, if so, controlling the related facilities of the thermal runaway early warning to start, and if not, indicating that the thermal runaway does not occur in the battery pack. The use safety and reliability of the thermal runaway early warning system are improved through judging the early warning conditions for many times.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.