A 2 MHz, 2 kW voltage-source inverter for low-temperature plasma generators: implementation of fast switching with a third-order resonant circuit

This paper presents a specially designed third-order resonant circuit intended to achieve fast switching operation for a voltage-source series-resonant inverter using four MOSFETs. The third-order resonant current superimposed on a sinusoidal load current helps to quickly charge or discharge the output capacitance of each MOSFET. This results not only in a reduction of the time required to turn the MOSFET on and off, but also in an improvement of the displacement factor of the inverter. Moreover, the third-order resonant circuit acts as a low-pass filter to eliminate the parasitic oscillation between line inductance and stray capacitance. The viability and effectiveness of the third-order resonant circuit is verified by a 2 MHz, 2 kW prototype inverter developed for a low-temperature plasma generator