Arc flash mitigation using active, high-speed switching

Abstract

One method of mitigating arc flash hazards associated with medium voltage switchgear is the installation of active, high speed switch (HSS) systems. These systems are designed to detect and quench a burning internal arc in less than one third of one electrical cycle. The internal arc is extinguished by the high speed switch's action of re-directing the fault current path from arcing through open air back to the intended current path of the switchgear bus. The new lowimpedance current path provided by the high speed switch operation collapses the voltage at the point of the fault to near zero so that the arc is no longer sustainable.