Ultra-fast busbar protection employing fast S transform of current signals

Abstract

This paper presents a new method for fast busbar protection based on S transform of current signals in a substation. In this method high-frequency components of current signals, generated by faults, are extracted by applying fast S transform at the points where current transformers (CTs) of substations are installed. Then, the results are processed and by employing the proposed decision rules, external faults (bay faults and line faults) are discriminated from internal ones. According to the simulation results, the proposed algorithm has high security and dependability and very fast operation and it is immune to fault type, fault inception angle (FIA) and fault resistance.