A waveform-dependence lightning impulse corona model in PSCAD/EMTDC for investigating surge propagation on transmission lines

This paper proposes a waveform-dependence lightning impulse corona model and develops it in PSCAD/EMTDC. The model computes corona initiation delay time by the critical volume method and considers the ionization relaxation process in corona space charge generation. Thus, the model can calculate corona capacitance and charge caused by the various waveform lightning impulses. A simple algorithm is proposed to avoid iteration in the solution process to apply the model to electromagnetic transient program for lightning overvoltage analysis. The accuracy of the model is verified by comparing the simulation results with measurement results available in the literature. Based on this model, we investigate the effect of the waveform on the attenuation and deformation of lightning impulse propagation on transmission lines. The results indicate that as the propagation distance increases, the attenuation rate of the voltage peak gradually slows down, and the front time linearly increases with distance. As the front and tail time decreases, the attenuation and deformation of lightning impulses caused by corona become more severe.