Analysis of regenerative braking efficiency — A case study of two electric vehicles operating in the Rotterdam area

This paper describes the analysis of the efficiency of regenerative braking of two electric vehicles operating in the Rotterdam area. The methodology of this research consists of a real time driving cycle measurement, measuring and modelling the battery pack and modelling the complete drive train of the vehicle. In the last phase, measurements on a rolling road Dyno test bench will be carried out in order to further verify simulation results and to improve the vehicle model. To analyze the efficiency of regenerative braking, we determined the ratio of brake energy and propulsion energy during the driving cycle, the efficiency of propelling the vehicle and the efficiency of converting brake energy into useful energy. The relative energy gain that can be obtained by regenerative braking is the product of these factors. Simulations show that the energy reduction of the vehicles under test can be more than 20% by applying regenerative braking.