Resonance behaviour of a pulsed electronic control gear for dielectric barrier discharges

A dielectric barrier discharge (DBD) light source, characterized as a capacitive load with a poor power factor, is operated with the sinusoidal pulse (SP) topology to obtain high efficiency of the radiation source as well as of the electronic control gear. The topology provides a pulse consisting of three sinusoidal half-waves that causes three alternating ignitions to obtain high plasma efficiency and homogeneity. Beside the main resonance providing a resonant voltage overshoot to drive the DBD, parasitic resonances occur between pulses. Especially the parallel resonance among DBD capacitance and transformer´s mutual inductance is of concern as it can affect efficiency and reliability. This paper describes the operation mode of the SP topology, mechanisms of formation and ways to manage parasitic resonances. Parameter variation of circuit components and variation of semiconductor switching patterns have been investigated. Enhanced switching patterns showed significant advantages compared to the standard switching pattern.