Experimental studies on effects of surface morphologies on corona characteristics of conductors subjected to positive DC voltages

As the surface conditions play a significant role on corona discharge and its related effects of the conductors, the influence of fine particulate matter on positive-polarity, direct-current conductors was studied experimentally in this study. The surface morphologies of the conductor could be discovered from the experiments. The typical morphologies are the parallel chains of particles. To evaluate the surface condition quantitively, the surface roughness of the conductors is measured. It is found that the applied voltage and testing time have a great influence on the surface condition. After that, the corona characteristics of conductors are tested. It reveals that the total ground level electric field and ion flow density increases with the surface roughness growing.