500kV狮洋至五邑线路电气不平衡度的研究

Research on Electric Unbalance Degree of 500 kV Shiyang to Wuyi Line

利用ATP-EMTP和MATLAB对广东省第一条500kV同塔四回线路——500kV狮洋至五邑线路的电气不平衡度进行了研究,计算结果表明,狮五线双回路段采用逆相序布置时,不换位时的电气不平衡度指标可以满足规程要求,四回路段的插入可以改善沿线的负序电压不平衡度。若线路考虑换位,双回路采用逆相序布置时,电气不平衡度指标改善不明显;当双回路采用异相序布置时,换位后狮五线回路间的负序电流不平衡度则得到明显改善。

Electric unbalance degree of 500kV Shiyang to Wuyi overhead transmission line, which is the first line of four circuits on the same tower in Guangdong Province, was studied with ATP-EMTP and MATLAB. The results showed that the value of electric unbalance degree accords with correlative regulations without conductor transposition as long as inverse phase sequence was employed in double-circuit segment. Application of four-circuit segment clearly decreased negative sequence voltage along the line. The application of conductor transposition would significantly improve the unbalance degree of negative sequence current flowing between circuits when heterogeneous phase sequence applied in double-circuit segment, on the contrary, electric unbalance varied little when inverse phase sequence applied.