Algorithm for digital differantial protection of power transformer

Abstract

본 논문에서는 변압기의 차동과전류 보호를 위한 inrush전류의 검출알고리즘이 제시되었다. 본 알고리즘은 최소자승법을 이용하여 샘플링된 차동전류로부터 제1, 제2 고조파 성분을 찾아 내었다. 여러 형태의 inrush절류 및 내부 고장 전류에 대한 본 알고리즘의 시뮬레이션 결과, inrush에 의 한 차동전류와 고장에 의한 차동전류에 대한 우수한 판별능력을 보여주었으며, 고장은 1-1.2 cycles(60Hz기준)내에 검출되었다.

An inrush current detection algorithm for the protection of power transformer is described with a differential overcurrent algorithm. The algorithm is based on a least-square curve fitting of the sampled differential current by a decaying DC and two harmonic components.

The proposed methods provides good discrimination between the differential current generated by the transformer energization-inrush current-and that produced by the internal faults. The digital simulation is performed on various inrush and internal conditions and the fault detection is done within 1-1.2 cycles based on a 60Hz waveform.

An inrush current detection algorithm for the protection of power transformer is described with a differential overcurrent algorithm. The algorithm is based on a least-square curve fitting of the sampled differential current by a decaying DC and two harmonic components.

The proposed methods provides good discrimination between the differential current generated by the transformer energization-inrush current-and that produced by the internal faults. The digital simulation is performed on various inrush and internal conditions and the fault detection is done within 1-1.2 cycles based on a 60Hz waveform.