EVALUATING CAPACITOR-SWITCHING DEVICES FOR PREVENTING NUISANCE TRIPPING OF ADJUSTABLE-SPEED DRIVES DUE TO VOLTAGE MAGNIFICATION

Nuisance overvoltage tripping of pulse-width modulated adjustable-spee d drives, due to switching of shunt capacitor banks at a utility's sub station and the subsequent voltage magnification which can occur at an industrial customer's utilization-voltage bus, is discussed. Adjustab le-speed drive design considerations affecting transient overvoltage r ide-through capability are identified and discussed, A comparative eva luation of three switching devices equipped with transient overvoltage control, namely, circuit breakers with pre-insertion resistors, circu it switchers with highly damped pre-insertion inductors, and controlle d closing devices, is presented.