Electrical modelling of homogeneous dielectric barrier discharges under an arbitrary excitation voltage

Abstract

In order to quantitatively describe the electrical working principles of dielectric barrier discharges (DBDs), a dynamic electrical model for homogeneous DBDs has been put forward that is composed of a new equivalent circuit for homogeneous DBDs and the equations derived from it. This model is a global and self-consistent model, valid for an arbitrary external excitation voltage. This model reveals instantaneous relations of internal electrical quantities in the gap (gap voltage, internal discharge current and internal power consumption process) to external electrical quantities (external voltage and external total current) and provides the theoretical fundamentals to calculate the temporal development processes of all internal electrical quantities in the discharge gap from the measured external voltage and external total current. The knowledge obtained of dynamic processes of DBDs in the discharge gap explains quantitatively the mechanisms that result in ignition, development and extinction of DBDs and provide physical interpretation of the measured external total current and other phenomena such as memory effect and multiple current pulses in one half period. In this model, several current terms (external total current, external displacement current, external discharge current, internal discharge current and internal displacement current) are introduced to distinguish the different currents involved in DBDs. Moreover, the equations for charge and energy deposition by one discharge and in one half period are derived. Applications of this model to studying a bipolar sine wave excited DBD and a unipolar pulse excited DBD are also included. This model has been proved to be a useful tool to understand DBDs better.