The influence of partial surface discharging on the electrical characterization of DBDs

The determination of internal electrical discharge parameters, such as plasma current and burning voltage, in dielectric barrier discharges (DBDs) relies on an equivalent circuit based on series capacitances for the discharge gap and dielectric material. An effective dielectric capacitance for the discharge can be obtained from Q-V diagrams, also called Lissajous figures, during discharging, which may not be a constant for a given DBD geometry. It has been shown experimentally that microdischarges, which can consist of narrow channels in either diffuse or filamentary form, may not fully cover the available discharge area. Here, we report measurements of the effective dielectric capacitance as a function of applied voltage amplitude in a DBD plasma jet system operating in N₂ and derive equations to determine the conductively transferred charge, burning voltage and the proportion of the electrode surface over which discharging occurs when the effective dielectric capacitance is not equal to the dielectric capacitance of the complete electrode area.