PROTECTIVE CIRCUIT FOR SERIES CAPACITOR BANKS

摘要

ABSTRACT OF THE DISCLOSURE:As overvoltage protection for a series capacitor in a high-voltage network a voltage-dependent resistor, built up ofmetal oxide varistors, is arranged in parallel with thecapacitor. In parallel with the resistor there is a sparkgap device consisting of two series-connected spark gaps forshunting the resistor in case of overload thereof. Theenergy for triggering the spark gap device is obtained froman auxiliary capacitor, which is charged during operation,and is supplied to one of the spark gaps via a switchingdevice, controlled by an overload detector, and a pulsetransformer. A metal oxide varistor is connected in serieswith the high voltage winding of the transformer. Thetransformer is connected so that the triggering pulse is inopposition to the voltage across the series capacitor.