Circulating Unbalanced Current and Its Influence of Double-Circuit UHV Transmission Lines
Li Bin1, Li Xuebin1, Ding Maosheng2, Bo Zhiqian3
1. Key Laboratory of Power System Simulation and Control of Ministry of Education, Tianjin University Tianjin 300072 China 2. Power Dispatch Center of Ningxia Antonomous Region Yinchuan 750001 China 3. ALSTOM T &D Stafford ST17 4LX UK
Abstract：Double-circuit transmission line is a trend for development of ultra high voltage (UHV) transmission system. The paper analyzes the wire layout of double-circuit line and characteristics of its impedance matrix. And then the sequence currents of double-circuit line are investigated. The paper points out that besides through unbalanced current, there are distinct circulating current when double-circuit line is in normal operation or external fault occurs. Furthermore, the circulating current is influenced by wire layout and external fault. Based on the simulation and verification of UHV double-circuit transmission line, the paper calculates the circulating unbalanced degree and investigates the influence of circulating unbalanced current on protection relaying and line losses.
李斌, 李学斌, 丁茂生, 薄志谦. 特高压同杆双回线的环流不平衡及其影响[J]. 电工技术学报, 2012, 27(4): 202-208.
Li Bin, Li Xuebin, Ding Maosheng, Bo Zhiqian. Circulating Unbalanced Current and Its Influence of Double-Circuit UHV Transmission Lines. Transactions of China Electrotechnical Society, 2012, 27(4): 202-208.
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2012, Vol. 27 
