A hybrid PWM approach for the traction motor control of Alternative Energy Vehicles

This paper focuses on high speed control of traction drive system for the Alternative Energy Vehicle (AEV). A hybrid approach is suggested in which a Sine Triangle Pulse Width Modulated (SPWM) inverter is used below the base speed and a square wave inverter is opted above the base speed. The transition between the SPWM and square wave is realized in a unique way by simply setting the frequency of carrier signal equal to zero. Thus the proposed methodology in a way uses only one PWM mode and the transition from the SPWM to square wave is seem less. The torque discontinuity which normally occurs during switching between the modes does not exist in the proposed strategy. The performance of proposed hybrid approach is validated through the simulation and experimental results on a small prototype induction motor for the volts per hertz speed control.