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 inten ded to achieve fast switching operation for a voltage-source series-resonan t inverter using four MOSFET's, The third-order resonant current superimpos ed on a sinusoidal load current helps to quickly charge or discharge the ou tput capacitance of each MOSFET. This results not only in a reduction of th e commutation period which is required to turn the MOSFET on and off, but a lso in an improvement of the displacement factor at the output of the inver ter. Moreover, the third-order resonant circuit acts as a low-pass filter t o suppress the parasitic oscillation between line inductance and stray capa citance. The viability and effectiveness of the third-order resonant circui t is verified by a 2-MHz 2-kW prototype inverter developed for a low-temper ature plasma generator.