A multi-level converter for SRM drive based EV applications with auxiliary load driving capability

Abstract

This article proposes a multi-level converter topology (MLCT) for a four-phase switched reluctance machine (SRM) drive-based electric vehicle (EV) application with auxiliary load driving capability. The proposed MLCT employs the same number of devices as in the conventional three-level-asymmetrical half-bridge (CTL-AHB) converter. The DC-link in the proposed MLCT topology is connected in series with an active boosting source, i.e., battery, via a bi-directional DC-DC converter to achieve higher voltage levels. The higher voltage levels result in faster energization and de-energization of the phase currents, resulting in improved average torque output. The proposed MLCT provides continuous power to the auxiliary loads for EV applications via a series battery. Depending on the series battery voltage/state of charge, the operating modes of the converter allow its charging via three modes. Analysis of different operating modes under motoring and regeneration/ braking is discussed with the simulation and experimental validation of the same.