Abstract:
This paper proposes a new low cost converter- inverter drive system for induction motor. It proposes a Dual Inductor Converter consisting of a resonant tank, voltage doubler rectifier and a snubber circuit which act as a DC-DC boost converter. Constant duty cycle control is used in the Dual Inductor converter to improve its efficiency. The input current of the converter system is distributed through the two boost inductors making its current ripple amplitude halved at twice the PWM frequency. The output of the converter system is given to the inverter system. For the voltage source inverter, different PWM strategies are compared and the most efficient method is adopted based on its harmonic performance. The THD of PWM, SPWM and SPWM with third harmonic injection is analyzed theoretically. The system have high lifetime and is having low cost.

Keywords: Hysteresis control, DC- DC Converter, AC motor drives, Third Harmonic Injection