계통사고시 지수함수 형태로 감소하는 DC-Offset 성분을 계전신호에서 제거하는 Digital Filter 디자인

Digital Filter Design for Removing Exponentially Decaying DC-Offset Component from Relaying Signal

Power system fault transient signals are highly distorted due to the presence of high frequency components in the voltage and current signals and an exponentially decaying dc-offset component in the current signals. Modern protective relays have to make reliable fast decisions about the nature of a fault in the presence of such transients. To use a dc-offset removing filter makes relay algorithms much fast and reliable for detecting a fault. In this paper, several dc-offset removing filters are described, and characteristics of them are compared.