METHOD AND CIRCUIT FOR ARC SUPPRESSION

摘要

A method and circuit are provided for suppression of arcing across trip contacts in a protection relay of an AC power distribution system. The trip contacts are connected into a power circuit for providing DC current to a solenoid of an AC power circuit breaker. The arc suppression circuit includes a storage capacitor and a field effect transistor having a gate, a source, a drain, and a variable resistance. The source and the drain are coupled across the trip contacts. A voltage control circuit that includes a capacitor and a voltage divider controls the voltage at the gate of the transistor. When the trip contacts move apart, DC current energy is stored in the storage capacitor and DC current energy is dissipated in the transistor. The voltage across the trip contacts is controlled during and after the period in which the contacts are moving apart.