Observer-based Fault Diagnosis Method for Electric Vehicle Lithium-ion Battery Sensors

Abstract

The invention relates to a fault diagnosis method of a lithium ion battery sensor of an electric vehicle based on an observer, and belongs to the technical field of battery management. The method comprises the following steps: determining parameters of a lithium ion battery, and establishing an electrothermal coupling dynamic model of the lithium ion battery of the electric vehicle; performing anopen circuit voltage test and an HPPC experiment on the measured battery to obtain characteristic parameters of the battery under different ambient temperatures; establishing a relationship between battery OCV and SoC, and identifying the parameters in the electrothermal coupling dynamic model by using a recursive least square method with a forgetting factor to obtain a quantitative relationship among the battery parameters, the ambient temperatures and the battery SoC; and importing current, a voltage and a temperature sensor measured value into a fault diagnosis and separation algorithm of the lithium ion battery based on the observer, estimating a quantity of state through an extended Kalman filter algorithm to generate a residual, and performing residual evaluation by using a CUSUM test method, and finally achieving fault diagnosis and separation of the lithium ion battery sensor according to combined response conditions of different residuals.

Description

technical field [0001] The invention belongs to the technical field of battery management, and relates to an observer-based fault diagnosis method for lithium-ion battery sensors of electric vehicles. Background technique [0002] In response to the increasingly severe global climate and energy crisis, the automobile industry, which is closely related to human life, is at the forefront of changes. In recent years, electric vehicles have become the focus of pursuit by various countries due to their inherent advantages in emissions and energy consumption. The related research field has become a hot spot in academia and engineering circles. The power battery is the main energy source of electric vehicles and the most important part of electric vehicles. The operating performance of this component is directly related to the driving experience of electric vehicles and the safety of passengers' lives and property. In order to monitor the status of the power battery pack and ensure...

AI Technical Summary

Problems solved by technology

However, there are relatively few literatures on the fault diagnosis of electric vehicle power battery sensors, and the results are relatively limited.

Images