배전계통 고장점 표정 알고리즘 적용 연구

This paper presents a discrete wavelet analysis based algorithm to address the fault impedance calculation under transient state in radial power distribution networks. The fault impedances have been derived under different fault conditions. Furthermore, a recursive fault distance estimation method is proposed utilizing the measured fault impedance and power line parameters. The proposed scheme can resolve the errors caused by the non-homogeneous power lines, the presence of lateral loads since, the fault impedance will always be updated with the recursive form. For the verification of the proposed scheme, a filed test has been peformed with varying fault resistances in the 22.9(㎸) radial system. Power meters and fault locators were installed at the substation. It was figured out that the performance of the discrete wavelet and the recursive scheme are very good even for high fault resistance condition.