A circuit approach to fault diagnosis in power systems by wide area measurement system

Abstract

Fault diagnosis following a disturbance in a power system is of great importance for the operators in the control center as a prerequisite for system restoration. In this article, for the first time, an analytic method for fault diagnosis, using the wide area measurement system (WAMS) and employing circuit rules, is developed. Instead of conventional information about status of protective relays and circuit breakers, voltage and current phasors at different points of the power network after fault occurrence are utilized. Because most of the power systems will be equipped with WAMS consisting of high-speed sampling features, the proposed method introduces a new application of WAMS for fault diagnosis without the need for additional hardware. In this method, with the aid of network impedance matrix, analytic voltage and current phasors resulted after a fault in each of the fault candidate points are compared with those monitored by WAMS. The faulted point is where the best fitting coincides with the monitored voltage and current phasors. The proposed method is applied on IEEE 118-bus test system where the results confirm its ability in wide-area fault diagnosis of large power networks. Copyright © 2012 John Wiley & Sons, Ltd.