CN-121980853-A - Battery thermal management assembly reliability verification method and system

CN121980853ACN 121980853 ACN121980853 ACN 121980853ACN-121980853-A

Abstract

The invention discloses a method and a system for verifying reliability of a battery thermal management component, wherein the method comprises the steps of obtaining real vehicle operation data, identifying and clustering abuse behavior patterns based on the real vehicle operation data, constructing a corresponding thermal load time sequence spectrum, establishing an electrochemical-thermal-force coupling-based battery internal short-circuit evolution model, dynamically generating a position, a triggering moment, an energy release rate and a local temperature rise curve of a thermal runaway initial trigger point, implementing a thermal runaway triggering experiment based on the internal short-circuit evolution model, monitoring response capability of the thermal management component in the thermal runaway propagation process in real time, constructing a verification platform, installing the thermal management component to be verified on the verification platform, executing an acceleration verification experiment, recording degradation tracks, judging the reliability requirement of the thermal management component, and realizing the integrity, high-fidelity assessment of the reliability of the battery thermal management component.

Inventors

ZHOU MENG
YE GUANGYAO
XUE JING
ZHOU JUNPU
LI ZEFENG

Assignees

江苏汉浦检测科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251231

Claims (10)

1. A method for verifying the reliability of a thermal management assembly of a battery, comprising the steps of: S1, acquiring real vehicle operation data, wherein the real vehicle operation data comprise vehicle geographic position information, a vehicle speed time sequence, an acceleration change sequence, a power battery charge state sequence, a charging event record, environment temperature data and a cooling system working state log; s2, based on real vehicle operation data, identifying and clustering out abuse patterns, constructing a corresponding thermal load time sequence spectrum, and taking the thermal load time sequence spectrum as an input boundary condition for verifying the reliability of the thermal management assembly, wherein the thermal load time sequence spectrum comprises battery monomer heat production power, module-level temperature gradient, cooling liquid flow requirement and electrical load of the thermal management assembly; s3, establishing an internal short-circuit evolution model of the battery based on electrochemical-thermal-force coupling, wherein the internal short-circuit evolution model dynamically generates the position, the triggering moment, the energy release rate and the local temperature rise curve of an initial trigger point of thermal runaway by simulating the physical processes of lithium dendrite growth, diaphragm local melting and micro-region electronic conduction; S4, based on a thermal runaway triggering condition generated by an internal short-circuit evolution model, performing a thermal runaway induction experiment on a battery pack level, and monitoring the response capability of a thermal management component in the thermal runaway propagation process in real time, wherein the response capability comprises a coolant flow maintenance capability, valve action reliability and sensor signal integrity; s5, building a verification platform, wherein the verification platform can simultaneously apply five types of stresses of high temperature, high humidity, mechanical vibration, electric load fluctuation and chemical corrosion of cooling liquid; S6, installing the thermal management component to be verified on a verification platform, superposing a thermal load time sequence spectrum and a thermal runaway triggering condition in the operation process of the thermal management component to be verified, executing a full life cycle acceleration verification experiment, and recording the degradation track of key performance parameters of the component along with time; And S7, fitting failure time data of the assembly by adopting a Weibull distribution model based on the degradation track, calculating the reliable service life under specific confidence, comparing with a designed service life threshold, and judging whether the thermal management assembly meets the reliability requirement under a real abusive scene.
2. The method for verifying the reliability of a thermal management assembly for a battery according to claim 1, wherein in S2, the abuse mode comprises a continuous multiple direct current fast charge mode, a fast charge mode immediately after high-rate discharge, a high frequency shallow charge and shallow discharge mode in a long-term low-charge state, and a continuous high power output mode in a high-temperature environment.
3. The method for verifying the reliability of a thermal management assembly for a battery of claim 1, wherein in S2, constructing a thermal load timing spectrum comprises: Based on an electrochemical-thermal coupling simulation model, calculating the heat generation power of the battery monomer by taking a vehicle running track corresponding to an abuse mode as input; Solving a modular temperature gradient through a three-dimensional heat conduction equation; back-pushing the coolant flow demand according to the heat balance equation; determining the electrical load of the thermal management assembly according to the thermal management assembly specification and the actual control strategy; the battery cell heat generation power, the module level temperature gradient, the coolant flow demand and the electrical load of the thermal management assembly are aligned in time to form a thermal load time sequence spectrum.
4. The method for verifying the reliability of the battery thermal management assembly according to claim 1, wherein in the step S3, establishing the internal short-circuit evolution model comprises the following steps: On the finite element mesh nodes, the lithium dendrite growth rate is described using the Butler-Volmer equation, The Arrhenius type thermal degradation kinetic equation is adopted to represent the diaphragm local melting, an exponential relation model of micro-region electron conduction probability and local current density and temperature is established, And (3) carrying out coupling iterative solution on the process, and judging that the internal short circuit occurs when the micro-region electronic conduction probability exceeds a set threshold value and the local temperature exceeds a set temperature.
5. The method for verifying the reliability of a thermal management assembly for a battery according to claim 1, wherein in S4, performing a thermal spread induction experiment comprises: Setting a local heating device consistent with the initial trigger point position of thermal runaway in the battery pack to be tested, wherein the heating power of the local heating device changes along with time so as to reproduce the energy release rate; And collecting the flow of the cooling liquid, the state of the electromagnetic valve and the signals of the temperature sensor in real time, and judging the response capability according to the flow attenuation, the valve response time and the signal abnormality.
6. The method for verifying the reliability of the battery thermal management assembly according to claim 1, wherein in the step S5, the verification platform comprises a temperature and humidity control cabin, a six-degree-of-freedom electric vibration table, a programmable direct current power supply and a closed-loop cooling liquid circulation loop; the temperature and humidity control cabin is used for regulating and controlling high-temperature and high-humidity environments, the six-degree-of-freedom electric vibrating table is used for applying mechanical vibration based on real road power spectral density, the programmable direct current power supply is used for simulating electric load fluctuation, and the closed-loop cooling liquid circulation loop is used for controlling chemical corrosion of cooling liquid.
7. The method for verifying the reliability of a battery thermal management assembly according to claim 1, wherein in the step S6, when a full life cycle acceleration verification experiment is performed, an acceleration factor is set according to an equivalent damage principle, and the acceleration factor is calculated by combining a temperature acceleration model and a vibration fatigue model so as to ensure that the accumulated damage in a verification period is equal to the total damage in a real vehicle service period.
8. The method for verifying the reliability of a thermal management component of a battery according to claim 1, wherein in S7, fitting the component failure time data by using a Weibull distribution model comprises obtaining shape parameters and scale parameters of the Weibull distribution by using a maximum likelihood estimation method, calculating the reliable life under a set confidence level, and comparing the reliable life with a design life threshold.
9. A battery thermal management assembly reliability verification system based on the verification method of any one of claims 1-8, comprising: the acquisition module is used for acquiring real vehicle operation data; The identification module is used for identifying and clustering out abuse patterns based on the real vehicle operation data; the thermal load time sequence spectrum construction module is used for constructing a corresponding thermal load time sequence spectrum aiming at each abuse behavior mode; the internal short-circuit evolution modeling module is used for establishing a battery internal short-circuit evolution model based on electrochemical-thermal-force coupling; The thermal runaway trigger execution module is used for executing a thermal runaway induction experiment by utilizing the thermal runaway trigger condition generated by the internal short circuit evolution model; the loading platform is used for simultaneously applying five types of stresses, namely high temperature, high humidity, mechanical vibration, electric load fluctuation and chemical corrosion of cooling liquid; the verification module is used for installing the thermal management component to be verified on the loading platform and executing a full life cycle acceleration verification experiment; and the judging module is used for judging the reliability based on the degradation track of the key performance parameters of the component.
10. The system of claim 9, wherein the thermal load timing spectrum construction module is configured to calculate battery cell generated thermal power, module level temperature gradients, coolant flow requirements, and thermal management component electrical loads based on the electrochemical-thermal coupling simulation model and to form a thermal load timing spectrum in time-series alignment.

Description

Battery thermal management assembly reliability verification method and system Technical Field The present invention relates to reliability verification of a thermal management assembly of a battery, and more particularly, to a method and a system for verifying reliability of a thermal management assembly of a battery. Background In the prior art, the reliability verification of battery thermal management components mainly relies on standardized test procedures, the core of which is based on predefined standard driving cycles and sequential stress loading patterns. The method generally applies stress factors such as temperature, vibration, electric load and the like on a time axis in sequence, and simulates a comparatively ideal or sectionally simplified working condition environment. Although the framework has good standardability and comparability, the construction of the test scene often has obvious differences with the complex, dynamic and multi-stress coupling real environment faced in the actual vehicle running, so that the verification working condition and the real use condition are seriously disjointed. Specifically, the standard driving cycle generally represents an average and typical driving mode, and it is difficult to cover the diversity, randomness and severity of frequent rapid acceleration, continuous running at high speed, extreme environmental temperature changes, and the like existing in actual driving of the user. The sequential stress loading mode can not fully simulate the comprehensive effect of simultaneous interaction of multiple physical fields (such as heat, machinery and electricity) in the actual driving process. The test design which is separated from the true coupling relation makes the potential failure mode of the battery thermal management component, especially the problems of performance degradation, material fatigue, abnormal response of a control system and the like under the synergistic effect of multiple stresses, difficult to be effectively excited and exposed in the verification stage. Disclosure of Invention The invention overcomes the defects of the prior art and provides a method and a system for verifying the reliability of a battery thermal management assembly. In order to achieve the aim, the technical scheme adopted by the invention is that the reliability verification method of the battery thermal management assembly comprises the following steps: S1, acquiring real vehicle operation data, wherein the real vehicle operation data comprise vehicle geographic position information, a vehicle speed time sequence, an acceleration change sequence, a power battery charge state sequence, a charging event record, environment temperature data and a cooling system working state log; s2, based on real vehicle operation data, identifying and clustering out abuse patterns, constructing a corresponding thermal load time sequence spectrum, and taking the thermal load time sequence spectrum as an input boundary condition for verifying the reliability of the thermal management assembly, wherein the thermal load time sequence spectrum comprises battery monomer heat production power, module-level temperature gradient, cooling liquid flow requirement and electrical load of the thermal management assembly; s3, establishing an internal short-circuit evolution model of the battery based on electrochemical-thermal-force coupling, wherein the internal short-circuit evolution model dynamically generates the position, the triggering moment, the energy release rate and the local temperature rise curve of an initial trigger point of thermal runaway by simulating the physical processes of lithium dendrite growth, diaphragm local melting and micro-region electronic conduction; S4, based on a thermal runaway triggering condition generated by an internal short-circuit evolution model, performing a thermal runaway induction experiment on a battery pack level, and monitoring the response capability of a thermal management component in the thermal runaway propagation process in real time, wherein the response capability comprises a coolant flow maintenance capability, valve action reliability and sensor signal integrity; s5, building a verification platform, wherein the verification platform can simultaneously apply five types of stresses of high temperature, high humidity, mechanical vibration, electric load fluctuation and chemical corrosion of cooling liquid; S6, installing the thermal management component to be verified on a verification platform, superposing a thermal load time sequence spectrum and a thermal runaway triggering condition in the operation process of the thermal management component to be verified, executing a full life cycle acceleration verification experiment, and recording the degradation track of key performance parameters of the component along with time; And S7, fitting failure time data of the assembly by adopting a Weibull distribution model based on the degradation