765-kV Station Insulation Coordination

Specially designed arresters are used in the American Electric Power 765-kV station insulation coordination as a first line of defense against overvoltage. The arresters have the ability to withstand sustained and dynamic overvoltages in excess of their rating. They also have the ability to discharge repetitively. Use of these arresters permitted 1800-kV BIL ratings for transformers, reactors, and circuit breakers. A performance criterion for bus flashover was established in terms of probability. New methods were used to test station insulator withstand and contamination performance.