Switching Surge and Insulation Coordination of Ehv Power Circuit Breaker

The dependability of the digital calculation accuracies of switching surges is proven through several comparative studies with the field test results. It is also clarified that the resistor preinsertion closing of a circuit breaker is one of the most effective methods for reduction of switching surges. On the other hand, in factory tests, satisfactory results have been obtained on the withstand characteristics and the coordination between the across-the-open-pole insulation and the phase-to-ground of an EHV air blast circuit breaker against switching surges.