Capacitive current switching with circuit breakers

ALTHOUGH POWER circuit breakers are designed primarily to interrupt heavy inductive short-circuit currents, system growth in recent years has produced a greatly increased requirement of interrupting relatively lighter currents associated with the switching of capacitive kilovolt-amperes. This capacitive kilovolt-ampere requirement has manifested itself in long-distance high-voltage transmission lines, in relatively long high-voltage cables, and in large-size shunt-capacitor banks which are becoming a common fundamental unit in system design and operation. There is not necessarily a relationship between the ability of a circuit breaker to interrupt short-circuit currents and its ability to switch capacitance currents. It is recognized widely that high-frequency voltage and current oscillations may be produced which, if uncontrolled, may result in damage to apparatus or system outages.