Regenerative Braking with Load Emulation for Three-Wheeler Electric Vehicle Traction in Hilly Region Using IPMSM Coupled IM Drive

This paper presents a novel method of regenerative braking (RB) for extracting the maximum possible energy during the deceleration of an electric vehicle (EV). The method proposes a modified technique of applying PWM pulses to only lower three switches of the voltage source inverter (VSI). The duty ratio of these PWM pulses depends on the estimated back-emf value of the motor. Further, an integrated system for a three-wheeler (3W) EV is discussed where a seamless transition of switching occurs between acceleration and deceleration of the vehicle. In this paper, the distribution of braking force is considered between the front and rear wheels as per the vehicle dynamics principle. Moreover, the EV loading is emulated by controlling the slip speed of the coupled IM. To validate the idea, a comparison of the proposed method with the conventional method is shown on an experimental setup of 48 V, 3 kW IPMSM for the uphill and downhill traction/braking. The experimental results show that the proposed method recovers higher RB energy than the conventional method for the considered hilly drive cycle. This research also shows the significant braking response achieved through the proposed method, especially during the downhill motion of the EV.