Analysis of Recovery Characteristics of Three-Phase Transformer Type SFCL per Types of Faults According to Reclosing System

摘要

Quantity of consumed electricity is increasing due to increase of population and industrial development. Consequently, fault current is increased during occurrences of faults. For restricting these fault currents, in this paper, recovery characteristics per types of faults was analyzed by applying reclosing motion to 3-phase transformer type superconducting fault current limiter. Established reclosing cycle (CO-t-cycle-CO-t-cycle) is 5-10-7-20-5 cycle. (C: Close, O: Open) Electricity burden of SFCL is different according to types of faults. So, according to turn ratio, a test was carried out with regard to fault current limit per types of faults and recovery characteristics. In single line-to-ground fault and in double line-to-ground fault, it could be confirmed that it limits electric current because fault current of fault phase provides impacts on coiling wire of different sound phase. And it was also confirmed that fault current limit rate is lowered during double line-to-ground fault instead of single line-to-ground fault. When it is triple line-to-ground fault, it was confirmed that size of fault current limit of T-phase is lower than R-phase and S-phase. In addition, it could be confirmed that size of fault current limit is lower the more transformer secondary stream turn ratio is smaller. Also, it was also confirmed that time of recovery of superconducting element became shorter in open cycle the more turn ratio per types of faults is smaller. And power consumption affecting superconducting element was related to recovery time.