Bidirectional Converter withCoupled Inductor for High Gain and Low Ripple in PMBLDC Motor for Electric Vehicle Application

Abstract

This article presents a bidirectional DC-DC converter with a coupled inductor for low input current ripple in step-up operation and low output current ripple in stepdown operation for permanent magnet brushless DC (PMBLDC) motor drive based electric vehicle application. PMBLDC motor is deemed more suitable for an EV owing to its high efficiency and torque density. A Bidirectional DC-DC Converter (BDC) is designed and developed for motoring and regenerative braking (RB). In the present work, a BDC is designed to drive a 1 hp PMBLDC motor through a conventional Voltage Source Inverter (VSI). During the converter's step-up operation, EV's load cycle is emulated using a pulley belt setup being driven by a PMBLDC motor. The converter is operating in step-down during RB, the PMBLDC motor is coupled with an inertial load with the help of a belt. Simultaneously, the back Electromotive Force (EMF) of the PMBLDC machine is boosted by using the self-inductance of the PMBLDC motor and the VSI. The braking technique used in this work eliminates the traditional drawback of RB in step-down mode, as the power is extracted even when the motor's back EMF is lower than the voltage of the battery. The control strategy has been implemented by using the TMS320F28335 DSP controller for a developed prototype of the converter and driving the PMBLDC motor. The experimental results are compared to the simulation results and a good alignment has been found