웨이블렛 변환을 이용한 변압기 보호계전 알고리즘 개발

The Development of Protective Relaying Algorithm for Transformer Based on Wavelet Transform

Current differential protective relaying with harmonic restraint module is, in general, used to protect transformer. But It is hard to distinguish inrush and internal winding fault with differential current protective relaying. This paper presents the new protective algorithm for transformers using 3-phase differential current's d1 coefficient values in wavelet transform. Various states of transformer was simulated using EMTP. Internal winding fault and inrush are classified within shorter time using the proposed algorithm.