FAULT LOCATION TECHNIQUES USING SYNCHRONISED/UNSYNCHRONISED MEASUREMENT OF PMU’S

Abstract

Bulk power is transferred from generating stations to load centres via power transmission lines. The transmission lines are prone to various faults during operation and may lead to power outages for a prolonged duration. Accurate fault localisation on a transmission line expedites the system repair, reduces the outages time and improves the power system reliability. Over the decades, various fault location methods based on impedance using fundamental voltage, current and frequency have been developed. However, complex topologies in the transmission network make this impedance-based fault location very difficult. In contrast, the knowledge-based approach is a highly complex technique. It requires information about the substations, transmission line parameters, atmospheric circumstances. This data is analyzed using artificial intelligence. The high frequency-based method uses high-frequency signals generated after fault, rejecting the reflected and refracted wave. The measurement of high frequency component carried out with the help of specially tuned filters. The high frequency-based algorithm is more complex and expensive and rarely used by utility engineers. To surpass the limitation of impedance-based, knowledge-based and high frequency-based fault location algorithm, travelling wave-based methods for fault location using PMU is focused on this project. Phasor measurement unit measurements provide real-time monitoring and control and enhance very precise fault localisation in the transmission line. The travelling wave-based methodology significantly contributes to transmission line protection and restoration in the shortest time period and maintain power system stability in the wide-area network. The thesis aims to simulate the fault localisation algorithm on the transmission network, utilising two ends synchronised and unsynchronised measurement. The algorithm also tested for a mutually coupled transmission line and a non-homogenous transmission line using synchronised measurement. The polarity of the wavelet transforms obtained using the first level detailed coefficient of the current travelling wave either at the local or remote ends or at both ends to identify the fault locations. The obtained result proved the effectiveness of the algorithm.