DC-Link Variable Control of 2-Stage Plasma Generator for Improvement of Efficiency in Intermediate-Load and Light-Load Conditions

A control method of input-parallel and output-series connected inverters with a 3-phase PWM converter for a plasma generator is proposed in this paper. By controlling a DC-link voltage with PWM converter considering the load level, the proposed control method can improve an efficiency in intermediate-load and light-load conditions compared with adopting conventional control method. Through the simulation and experiment, the efficiency of the 2-stage AC-AC converter according to control methods are compared.