Modeling and simulation of battery in electric vehicle battery test system

YU Cong, YAO Wei, WANG Zijing

(College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China)

Abstract: Aiming at the problems of unbalanced battery discharge and battery life shortened caused by the harmonic generated when electric vehicle is running, in order to test the harmonic of the DC current with different inductors and capacitors quickly, a test system model based on battery model was established in Simulink. Three kinds of popular equivalent circuit model of battery were introduced and compared, the secondorder RC model was analyzed. The effect of each part of the secondorder RC model based on test data was described, and the curve fitting of the nonlinear relationship between OCV and SOC by the method of least squares was presented in detail. The RC parameters in the equivalent circuit were identified. Vector control algorithm was introduced, which was used in the modeling of motor drive system. At last, the model of the whole system was established, and two tests were designed. The results indicate that the data obtained by the model is quite near to the real system, so it can be used to simulate the resistance and inductance value of real circuit.

Key words: battery modeling; electric vehicle; parameter identification