Characterization of surface discharges at high DC voltage superimposed by a medium frequency high voltage

Abstract:
The increasing use of power electronic topologies in future electrical energy grids leads to superposition of the grid voltage and medium frequency voltages. This paper deals with the basic investigations of surface discharges at these new composite voltages. High electrical stresses can cause surface discharges at dielectric interfaces, which can lead to irreversible destruction of high voltage insulation systems, especially at higher frequency voltages. Therefore surface discharges are studied at high DC voltage superimposed by a medium frequency high voltage. A discharge measurement system is presented. So it is possible to explain the characteristics of surface discharges at different composite voltages. The effects of medium frequency discharges must be considered for the technical design of insulation systems.