Overvoltages and Overvoltage Protection

The investigation of the transient overvoltage behaviour of high voltage systems with respect to the Basic Insulation Level (BIL) is of general interest. Voltage shapes, peak levels, frequency content and stress duration are essential parameters. For a specific stress evaluation using a numerical calculation tool, a representative circuit diagram has to be developed. The evaluation of each element in comparison with measurements gives the basis for calculation procedures. The knowledge of the specific transients are used for an optimisation process of the protection in high voltage systems and helps for updating strategies in future.