Battery cycle life estimation system and method for electric vehicle

Abstract

The invention relates to the technical field of power batteries, and provides a battery cycle life estimation system and method for an electric vehicle. The battery cycle life estimation method comprises the steps: when the vehicle is powered on or a charger emits an ignition signal, the current battery capacity C0 of a power battery is read; when the open-circuit voltage reaches interval end values of OCV intervals, the battery capacity Cv under the OCV intervals is recorded; the difference value between the battery capacity Cv and the mid-value of the battery capacity stored in the corresponding OCV interval is calculated, and if the difference value is smaller than a first preset difference value, the current battery capacity Cv serves as a sample to be stored in a battery capacity sample set corresponding to the corresponding OCV interval; the maximum capacitance, the minimum capacitance and the mid-value of the capacitances of the current OCV interval are updated, and the arithmetic mean value of the capacitances of the current OCV interval is calculated; and the cycle life SOH of the power battery is calculated and updated and displayed. The constraint that battery cycle lifeestimation is conducted according to experimental data of 1000 times of battery charge and discharge cycle testing is broken through, the development period is short, and thus the battery cycle lifeestimation system and method are closer to actual development needs of projects.

Description

technical field [0001] The invention relates to the technical field of power batteries, and provides a system and method for estimating cycle life of electric vehicle batteries. Background technique [0002] The battery cycle life estimation system (SOH) of an electric vehicle is the basis of the remaining battery capacity estimation system (SOC). The accuracy of the SOH determines the accuracy of the SOC, and the estimation of the cruising range of the vehicle is based on the SOC, so the accuracy of the SOH directly affects The accuracy of vehicle mileage estimation affects the driver's subjective driving experience. [0003] The traditional SOH of electric vehicles is based on the test data of 1000 battery cycle tests, and the SOH is obtained by summarizing the linear empirical formula. This traditional solution requires more than three years of cycle tests on the one hand, far exceeding the entire development cycle of an electric vehicle. ; On the other hand, the empiric...

AI Technical Summary

Problems solved by technology

[0004] The invention provides a battery cycle life estimation system for electric vehicles, aiming to solve the problem that the existing cycle life estimation system has a long research and development period and is not suitable for the actual working conditions of the whole vehicle

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