Influence of Battery Voltage Level on Regenerative Braking Capability and Overall Efficiency of Electric Vehicles

This paper discusses the effect of battery voltage level on the regenerative braking capability as well as the overall efficiency in Electric Vehicles (EVs). The performance of regenerative braking and the system losses in EVs depend on various factors including battery voltage level. In this study, a MATLAB/SIMULINK model of an EV powertrain and energy storage is utilized to simulate road load conditions and to analyze the effect of different battery voltage levels on regenerative braking capability and overall efficiency of the vehicle. The results of applying different battery voltage levels are compared with each other from the viewpoint of energy savings as well as total ohmic losses. The results show that ohmic losses decrease, and more energy can be harvested during brake instances by utilizing higher battery voltage levels. The results also indicate that regenerative braking improvements are significantly higher than the gain obtained from ohmic loss reduction.