Charge Simulation Method and Surface Charge Computation for Design of High Voltage Devices

This paper presents an overview of the charge simulation method (CSM) developments which started at the Technical University of Munich in the 1960s and continue until today. The CSM features and the corresponding formulations created during three major development phases are summarised. Altogether, eight types of equations used in the latest CSM-implementation are presented. The newest surface charging simulation procedure, which is one focus of this paper, has been illustrated by two examples of devices belonging to the medium voltage range: a triple point test arrangement and a silicon coated vacuum interrupter. A comparison of results between computations and a dedicated AC test enabled generalisation of the procedure for simulation of triple points. An evaluation of the extremal saturation charge on the silicon coating has shown its impact on LI-withstand and has indicated possible improvements of the insulation shape. The differences between the 2D CSM results and the results obtained using a 3D Boundary Element Method implementation are discussed.