Ultrafast Mechanical Switch for Hybrid Current Limiters

This proposed effort investigates the current and voltage interruption capability of a novel breaker contact design driven by a rugged ultra-fast actuation mechanism. The arc created by the opening contacts is forced to take the form of a thin cylindrical sheet between two close fitting insulating surfaces resulting in very high heat losses compared to free arcs. At any given current, the voltage required to sustain the lossy arc is much higher than a free arc since its input power must always balance its rate of energy loss. This contact design, when combined with the ultra-fast mechanical driver, may be capable of commutating fault currents into a parallel current limiting impedances in medium voltage power distribution systems without the solid state switch used in most of the emerging hybrid current limiting devices.