Unusual overvoltages caused by the generating effect of induction motors

Abstract

An overvoltage phenomenon that occurred at a nuclear power station in Taiwan is investigated. Simulations of the event reveal that two individual low-frequency overvoltages were caused by the interaction of induction motors (with flywheels) with the power line capacitance after they had lost power. Although these low-frequency overvoltages are insufficient to cause the failure of a circuit breaker they could have caused sufficient damage to the bushing insulation of the breaker that when a subsequent switching surge could cause the failure of the breaker. This failure lead to a blackout event.