Energy manegement using fuzzy controller for hybrid electrical vehicles

In electric vehicles, the battery is exposure to an excessive stress because of continuously charging and discharging. In this paper, a hybrid energy storage system (HESS) combined of supercapacitors (SC) and batteries is deployed. An energy management strategy based on fuzzy logic controller (FLC) and rule based controller (RBC) are proposed to mitigate the high stress problem and increase the battery lifetime. The battery and SC sizes are optimized based on a power demand profile. Based on simulation results, three different HESSs along with FLC and RBC are compared, in their SC voltages and battery currents viewpoints, and the best one is introduced. FLC has advantageous to alleviate battery current fluctuations in comparison with RBC, but RBC has higher battery lifetime.