Time-domain based fault location for series compensated transmission lines without requiring fault type

Abstract

Accurate fault location algorithms enable a quicker return to operation of faulted lines. The previously published fault location algorithms for series compensated transmission lines need the fault type and/or the compensator model to be known before fault location estimation. Thus, the accuracy of them is highly related to the fault type classification method and/or modelling of the compensator. This article suggests a fault location scheme for transmission lines compensated by series devices without requiring fault type based on synchronized instantaneous values collected from both ends of the line along with taking advantage of the distributed parameter line model in the time domain. The main advantages of this method are: (1) It not only determines faulty phases, but also estimates the fault location, simultaneously; (2) It is also independent on models of the series devices, so that the scheme is valid for transmission lines compensated by any series compensator. This paper examines the accuracy of the new algorithm for different fault situations with wide variations in system operating conditions in the presence of a Thyristor-Controlled Switched Capacitor (TCSC) and a Static Synchronous Series Compensator (SSSC). The results show that the fault type-classification and location accuracy of the method is high.