1. Southwest Jiaotong University Chengdu 610031 China 2. Shanxi Electric Power Research Institue Taiyuan 030001 China 3. Sichuan Electric Power Research Institue Chengdu 610072 China
Abstract:DC magnetic bias, caused by the current from the DC grounding electrode, threatens the safety of AC grid. At first, a simple and easy-to-use formula for calculating the DC surface potential was presented, which was based on typical three-layer soil structure. Secondly, in the verification, measured value of DC current of transformer neutral point was applied to decide the coefficient of the formula by editing nodal equation. Comparison of the calculated, simulation and measured value demonstrates high accuracy of the formula. Finally, DC current distribution in substations caused by DC grounding electrode was evaluated by predicting DC surface potential and step voltage in a HVDC with the formula mentioned above. Several substations were pointed out to take protective measures.
任志超, 续建国, 张一坤, 甄威, 吴广宁. 交直流互联系统直流地表电位简易算式[J]. 电工技术学报, 2011, 26(7): 256-263.
Ren Zhichao, Xu Jianguo, Zhang Yikun, Zhen Wei, Wu Guangning. Study of the Simple Formula of DC Surface Potential in AC-DC Interconnected Large Power System. Transactions of China Electrotechnical Society, 2011, 26(7): 256-263.
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