Active Voltage Control enhances overall operating efficiency of traction motor in electric bus

Bus voltage affects the characteristic curve of traction motor, as well as high-efficiency region. This paper discusses if it is possible to improve the motor efficiency by AVC (Active Voltage Control), and if so, to what extent. Based on China Bus Urban Cycle, an 8-meter electric bus is studied via simulation in Matlab/Simulink. And the AVC controller is designed to determine the most efficient bus voltage in every time slot. The comparison of instantaneous motor efficiency is made between AVC and 624V. The results indicate that AVC has potential to enhance overall operating efficiency of traction motor in electric bus: 2.8% improvement of driving efficiency and 0.79% of regenerating efficiency can be achieved.