A wavelet-fuzzy power allocation strategy of battery-supercapacitor hybrid system for electric vehicles

Abstract

A wavelet-fuzzy power allocation strategy of battery-supercapacitor hybrid energy store system(HESS) for electric vehicles is proposed in this paper. In the proposed strategy, wavelet decomposition decouples the transient dynamics power, while the fuzzy controller carries on the secondary distribution of load power between the two energy sources, according to energy levels of the power sources and load demand level. Compared with the traditional method using wavelet decomposition only, this strategy can effectively reduce the consumption of the battery, prolong the battery lifetime and adjust the state of charge (SOC) of supercapacitor. The simulation is performed on an IM240 driving cycle, and the results show the effectiveness of the control strategy.