Multi-Terminal Nonhomogeneous Transmission Line Fault Location Utilizing Synchronized Data

This paper presents an innovative fault location method for multi-terminal nonhomogeneous transmission lines by using synchronized voltage and current phasors acquired from phasor measurement units or intelligent electronic devices. We extend the previously published two-terminal and three-terminal nonhomogeneous transmission line fault location techniques developed in our lab to multi-terminal nonhomogeneous transmission lines. Specifically, a graph theory based indices and an optimal calculation data window is applied to identify the faulty line branch and to mitigate the undesirable influence caused by dc decay and the arc phenomenon of circuit breaker. The high performance of the proposed fault location method is validated by simulation results and real world utility fault data.

I. Introduction

In power systems, transmission lines play a critical role to deliver power electricity from power plants to end users. In recent years, transmission systems are expanding due to the demand growing and installation of large-scale distributed energy resources (DERs). Sometimes, it is hard to find an appropriate location and a route for substations and transmission lines, respectively. Hence, multi-terminal transmission lines with tap points become a solution for planning engineers.