Line voltage detector for SMES system designed to protect from momentary voltage drop

For the precision industrial plants, a stable electrical power source is the one of the key components as known as well. Usually, a battery type UPS is used to protect computers from the power failure, but it cannot protect the whole plant because its capacity is too small to supply for all facilities. A short time SMES system is suitable to cover this problem. It will supply the enough power to the plant while the line voltage is momentary dropped. The target plant may be sensitive for the line voltage drop, a high-speed detection of voltage drop is required and a detector that uses two detect method in parallel, was developed. This paper introduces the voltage detector developed for the SMES system.