Insulation co-ordination for continuous operating voltages and temporary overvoltages

This paper presents an approach to the insulation co-ordination of electric-power installations in the scope of the continuous operating voltages and temporary overvoltages; this approach opens the possibility to calculate the necessary required withstand voltages of unit insulations for short-duration (1 min) power-frequency test voltage, with respect to continuous operating voltages and power-frequency temporary overvoltages and the necessary reliability of the operation of high-voltage power system installations.