Control and analysis of the high efficiency split phase PWM inverter

The traditional power switch phase leg is widely used in the power electronic devices. However, the short through of the phase leg is always a problem for reliability, efficiency, higher switching frequency. Besides, both of power device turn-on/turn-off time and the reverse recovery time of poor performance body diodes will limit the switching frequency and power conversion efficiency. This paper proposes a new split phase PWM inverter which could split the MOSFET based phase legs by coupled inductor to prevent the short through and disable poor performance body diode. The extended Schottky diodes could be adopted to eliminate reverse recovery loss. By using the traditional bipolar or unipolar PWM control schemes, the circulating current which is caused by the feature of inductors will exist in the circuit and will increase power loss. An advanced unipolar PWM control strategy is proposed in this paper to minimize circulation current and to improve power conversion efficiency. Simulation is done to verify the better performance of split phase PWM inverter and the proposed advanced unipolar PWM control strategy.