Mid Sweden University

In recent times, the boom in electric vehicle (EV) is increasing due to the development of highly efficient power converters and to reduce the fossil fuel dependency. Hence, the progress in both electric and hybrid vehicles are rising. However, the safety become an issue in EVs for operating at high voltage level. Therefore, the application of the low voltage motor in EVs is proposed. This helps to increase the safety in the vehicle and reliability of the system. The proposed voltage for such low voltage motor drives is 48V. This voltage level is also beneficial for integration of battery and ultra-capacitors (UCs). This paper proposes the state of art of designing power converters for low voltage motor drives. Additionally, a novel bi-directional DC-DC converter with reconfigurable transformer is proposed for driving low voltage motors. The proposed bi-directional converter can operate with wide input (12V-4SV) and wide output voltage (1.5V-24V) ranges for power level of 1. 2kW. Analysis of this system and operating principle of the novel converter are also included for different output voltage and current levels. The presence of UCs in the system helps to improve the control response required during accelerating and braking. The simulation results of the system are included in the paper for different voltage and speed levels. The preliminary experiment result is included in the paper.