Optimal Blending of Regenerative and Friction Braking at Low Speeds for Maximizing Energy Extraction in Electric Vehicles

Abstract

This paper proposes a new approach to maximize the harvested energy through regenerative braking process in electric vehicles (EVs) by optimal blending of regenerative and friction brakes. In the proposed approach, the low-speed boundary, under which regenerative braking capability of an EV is ineffective, is determined using the traction motor (TM) regenerative braking performance map. During braking at low speeds, if the TM operating point falls below the defined low-speed boundary, it is shifted to an optimal point on the map such that motor regenerative braking capability is utilized more effectively. A MATLAB/SIMULINK model that represents the vehicle TM is used to validate the proposed approach. The results show an increase in the extracted energy compared to a case where regenerative braking is completely disabled below the low-speed boundary.