Renewable Energy Distribution Network Overcurrent Protection Based on Positive-Sequence Sudden-Change Component Locus Identification

• Published in: 发电技术 Vol. 45; no. 4; pp. 753 - 764
• Main Authors: WANG Weijie, ZENG Xinjie, XU Yuantu, LI Shuyi, RUAN Canhua, TONG Ning, WU Xiaomei
• Format: Journal Article
• Language: English
• Published: Editorial Department of Power Generation Technology 01.08.2024
• Subjects: affinity clustering algorithm; distribution network; positive-sequence sudden-change component; relay protection; renewable energy
• ISSN: 2096-4528
• DOI: 10.12096/j.2096-4528.pgt.23078

ObjectivesWith the widespread integration of renewable energy, the uncertainty of power flow in distribution networks with neutral points grounded through small resistors has made the setting of traditional three-stage current protection increasingly complex, and reduced its sensitivity and reliability. To solve the above issues, a new type of current protection based on positive sequence sudden-change variable current phasor trajectory identification was proposed.MethodsFirstly, the magnitude and distribution characteristics of the positive sequence sudden-change variable current upstream and downstream of the fault point were analyzed. Secondly, using the affinity clustering algorithm, the defined “main fault path” based on the clustering results was identified. Finally, a novel searching method was proposed to identify the source of the positive sequence sudden-change variable, which was the last level feeder located on the main fault path, as the faulted feeder.ResultsSimulation research based on PSCAD shows that the proposed protection method can adapt to various fault conditions, is immune to the integration of renewable energy, and has high sensitivity and reliability.ConclusionsThe research findings are helpful to enhance the operational safety of distribution networks with neutral points grounded through small resistors, and improve the efficiency of fault detection.