EHD thrusters are a useful means to convert electric energy into kinetic energy. In our work we develop a theoretical (self-consistent) 2D model of an axisymmetric electrostatic plasma actuator for argon gas at low pressure. The discharge is sustained by secondary electron emission from the cathode, which is due to ion impacts on its surface. In order to avoid the short-circuit regime, we consider an RC series matching circuit when applying a voltage to the electrodes. Here we investigate mainly the current flow mechanism. We demonstrate that EHD flow can be simulated if appropriate boundary conditions are chosen.