Soft switching four quadrant DC-link inverter generating sinusoidal waveforms

A soft switching power converter topology for high frequency (HF) AC/DC/AC power conversion which synthesizes the sinusoidal output voltages and results in a considerable reduction of acoustic noise is proposed. The converter achieves soft switching without increasing the voltage or current ratings of devices and has the capability of HF and four quadrant operation. HF operation by soft switching provides several advantages such as high power density, low electromagnetic interference and high dynamic performance. The voltage stresses and the current stresses in this converter are limited to the supply voltage and the link current by the operation of a current free-wheeling circuit, and thus the VA ratings of devices are reduced to those of the hard-switched inverters. Simulation results are presented to verify the operational principle