Quad‐bus motor drive system for electrified vehicles based on a dual‐output–single‐inductor structure

Abstract

48 V electric system architecture has been recently introduced to accommodate an increasing number of electric components in mild hybrid electric vehicles. In this study, two additional DC buses are added for electric machines including 36 and 24 V AC- and DC-motor/actuator loads, in a 48/12 V power supply system. This structure can yield significant benefits, especially for electrified vehicles that have more electric machines and actuators. A single-inductor multi-output structure is employed, with a control strategy that produces linear transfer functions and is less sensitive to load variation, to accommodate multiple-bus motor/actuator drives. The proposed structure and control strategy can offer options for selecting proper bus voltages, optimising the electric machine's power density. Both simulations and experiments have been performed to verify the system structure and control schemes using 36 and 24 V electric machines connected to the additional dual-output buses on top of the existing 12/48 V bus structure.