An Asymmetrical Space Vector PWM Scheme for a Three Phase Single-stage DC-AC Converter

High-frequency link isolated DC-AC converters have been used in various applications such as uninterruptible power supplies, grid integration of renewable energy sources, and vehicle to grid mode of operation of the electric vehicles, etc. This paper proposes a novel asymmetrical space vector PWM (SVPWM) scheme for an isolated single-stage three phase DC-AC power converter. The isolated DC-AC converter consists of a full-bridge (FB) inverter at the DC side and a three phase 3 x 2 matrix converter at the AC side. The proposed asymmetrical SVPWM scheme provides zero voltage switching (ZVS) for the full bridge inverter and zero current switching (ZCS) for the matrix converter. It also mitigates the voltage spikes generated due to the energy stored in the leakage inductor of the intermediate high-frequency (HF) transformer. The experimental results of the proposed soft-switched asymmetrical SVPWM technique is presented based on a 3.3 kW isolated single-stage DC-AC converter unit developed with SiC MOSFETs.