Development of Phasor Measurement Unit Based Fault Detection and Faulty Line Classification in Electrical Power System

• Main Author: Muhammad Qasim, Khan
• Format: Thesis
• Language: English
• Published: Universiti Malaysia Sarawak (UNIMAS) 2019
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://ir.unimas.my/id/eprint/27537/2/Muhammad%20Qasim%20Khan.pdf; http://ir.unimas.my/id/eprint/27537/
• Institution: Universiti Malaysia Sarawak

Modern power system requires advanced and intelligent sensors based protection, such as Phasor Measurement Unit (PMU) that can provide faster, accurate and real-time data acquisition. Blackouts, that occurred since 1992-2016 with a common failure reason was the cascade line tripping of transmission lines (TL) relays. Wide area measurement systems can completely overcome these issues with efficient use of PMUs for protection of TL. This study first focuses on modifying the PMU model for standard test systems in a MATLAB Simulink environment. This model implements Non-Recursive Phasor Estimation (NRPE) algorithm. Secondly, the study proposes an index for faulty node classification (FNC) based on the positive sequence voltage (PSV) measurements of the pre-fault and post-fault conditions. The index of a bus with a maximum differential percentage is identified as a faulty bus. Thirdly, for a faulty line classification (FLC), this study develops the current angles differential scheme by introducing unwrapped dynamic phase angles using the modified PMU measurements. Hence, the comprehensive algorithm that includes FNC and FLC, is coordinated with all PMUs for accurate wide-area fault location. The robustness of the proposed approach has been validated using the IEEE 9-bus, 30-bus, and 39-bus test systems. The results verified higher accuracy of proposed FNC scheme in comparison to traditional FNC scheme based on minimum PSV selection. For the FLC, this study accurately located the exact faulty TL. Overall, robustness of the proposed algorithm is tested under different faults scenarios, taking into account several factors such as fault inception angles, line fault resistance, ground fault resistance, and the size of loads. Keywords: Differential protection, DFT, fault location, non-recursive phasor estimation, phasor measurement unit, unwrapped dynamic angles.