Efficiency and Performance Analysis of Battery-Ultracapacitor based Semi-active Hybrid Energy Systems for Electric Vehicles

This paper presents a comparative analysis of two semi-active configurations of Hybrid Energy Storage Systems for electric vehicles combining batteries and ultracapacitors. The analysis of a proper sizing of the battery and ultracapacitor bank according to the power requirement of the vehicle is first presented. In addition, a method to select the low pass filter cut-off frequency used for power split is proposed. Losses in each of the components of the system elements are analyzed and included in the model. For both configurations, a commonly used control strategy based on the load power separation is implemented and simulations for a scaled NEDC driving cycle are performed. Then, based on a loss and performance analysis, it is determined which configuration is the most convenient for this application.