Recognizing Ability of Local Currents During Two-Side Observation of Transmission Line

Abstract

The article is aimed at analyzing the various information and parameters involved in diagnosing the fault location on the power line and identifying the damaged branch if there are several branches. Relay protection algorithms widely use the separation of the short-circuit current into the previous and emergency components. The latter carries the basic information of the fault location. Recently, it was found that the emergency component can also be divided into two components, namely normal and local. The local component is particularly very important because the ratio of local currents shows a strong dependence on the fault location or on the damaged branch, but does not depend on the fault current and, most importantly, does not on the part of the electrical system external to the observed line. The influence of unobserved branches on the accuracy of determining the damaged location by the proposed measurement is analyzed. Attention is drawn to the correlation between local currents algorithm and the emerging trends in merging or unifying the characteristics of relay protection and automation.