Taniguchi-pulse width amplitude modulation for high efficiency power train of electric vehicle

Abstract

This paper proposes a Taniguchi-pulse width amplitude modulation (T-PWAM) method as a motor control method for increasing the efficiency of a power train of an electric vehicle (EV). A conventional sinusoidal pulse width modulation (SPWM) method of the motor control methods has a feature of a high switching frequency. This feature causes a high switching loss in a inverter. The T-PWAM method has two advantages compared to the SPWM method. Firstly, the switching frequency of the inverter is reduced to a maximum of one-third. Secondly, the voltage utilization rate is increased by a maximum of 18.1 %. Therefore, the switching loss can be reduced by the T-PWAM method. Additionally, The T-PWAM method has a voltage compensation function for increasing the usable speed range of the EV. In the simulation, this paper verified that the T-PWAM method increased both the inverter and motor efficiency compared to the SPWM method. Furthermore, three experimental results were verified. Firstly, the output voltage waveforms of a DC-DC converter and inverter with the T-PWAM method could be accurately generated. Secondly, the inverter efficiency in the SPWM and T-PWAM method were measured with the three phase resistance. Finally, the motor control with the T-PWAM method was implemented at an operating point.