IHTS development for Uninterruptible Power Supply at UPS fault

This paper is about high speed conversion device in UPS(Uninterruptible Power Supply System). When interrupted, the situation is finally sensed in UPS output: this device detects such interruption preventing any fault in load and converts to Bypass line to prevent interruption of electric power. This system is composed of additional independent system that is operational in an uncontrollable situation of UPS system, compared to conventional UPS system that detects output power and converts when UPS system is out of the reference voltage. Also, UPS interior short circuit accident appears most greatly as an effect of fault in industry field. So this paper proposes UPS-IHTS (uninterruptible power supply-Isolation control high speed transfer switch) to consider a point of contact state at conversion to minimize the effect of fault in load and grid.