PARTICLE-IN-CELL SIMULATION OF BIPOLAR DC-CORONA

Most of the existing methods for calculating de ionized fields of mono polar and bipolar corona have ignored the ionization regions and exclu ded the transient phenomena of corona discharges. In this paper, bipol ar de corona was studied with a two-dimensional particle-in-cell simul ation, which allowed us to model time-dependent, nonlinear, microscopi c phenomena involved in the corona discharge. The technique followed s imulation particles that represented electrons, positive ions, and neg ative ions, and self-consistently calculated the associated electric f ield that determined the simulation particle motion. Finite element an d charge simulation methods were used to solve Poisson's equation whil e a finite difference scheme was applied to move simulation particles. Multi-scale techniques (nonuniform triangle mesh and variable time st ep) were employed to reduce numerical noise and increase simulation ef ficiency. The particle-in-cell simulation was applied to a cylindrical bipolar corona cage problem. Simulation results included one primitiv e streamer, multi-electrode induced currents, conductor temperature ef fects, memory effects, the approach to a stationary state, and transie nt corona saturation.