Three-Level Single-Phase Current-Source AC/DC/AC Conversion System with Reduced Switching Device Counts

摘要

This paper proposes a new circuit configuration of a three-level single-phase AC/DC/AC conversion system with reducedswitching device counts. The circuit incorporates a three-level single-phase half-bridge current-source PWM inverter and athree-level single-phase half-bridge current-source PWM rectifier. The inverter circuit part is constructed from duality principleof the conventional voltage-source PWM inverter, while the rectifier circuit part is built by means of mirroring and reversingprocess of the inverter part. By combining them into one circuit with two reactors as the energy buffers, the converter can notonly convert the voltage and frequency, but also can reduce the total harmonic distortion with reduced reactor size, comparedwith a two-level one according to the circuit simulations.