Design and Implementation of Power System Protection Scheme Using Hybridization of Signal Processing Techniques

Abstract

The renewable energy (RE) sources-based power plants are being continuously integrated to the network of existing power system for meeting the growing demand of clean and low-cost energy. This has changed nature of line feeders from passive to active. The bidirectional power flows are observed on the utility feeders at different time of the day. Therefore, conventional relays used for protection of the power network are needed to be improved by the application of hybrid combination of the signal processing techniques to improve performance and reliability of the protection schemes. This has been considered in this thesis for investigations. newlineThis research work designed a hybrid scheme for transmission line protection (HSTLP) by application of Stockwell transform (ST), Wigner distribution function (WDF) and Alienation coefficient (ACF). The current waveforms are analyzed using the ST, WDF and ACF to compute Stockwell fault index (SFI), Wigner fault index (WFI) and Alienation coefficient fault index (ACFI) respectively. These fault indexes are used to derive hybrid signal processing fault index (HSPFI) for implementing to detect transmission line faults. Peak value of HSPFI is checked for a threshold magnitude (TH) to identify faults. Statistical formulation is proposed for fault localization on power line. Fault categorization is performed considering faulty phases number newline