摘要
特高压系统输电容量大,电压等级高,全封闭组合电器壳体及接地网环流值较大,在正常运行下产生很大的环流损耗。结合我国某特高压开关站,建立特高压HGIS的三维立体模型,运用有限元法对HGIS壳体与接地网构成的电气回路中电磁耦合过程进行计算,得出HGIS壳体环流值及相应的温升。运用壳体环流值的计算结果与场路耦合的方法计算接地网的环流值。分析表明:在母线额定电流为6 300 A的情况下,壳体环流最大值在3 500 A左右;采用双层水平地网可以将主地网环流控制在20 A以内,次地网环流控制在700 A以内,但相应的短接线电流较大,最大温升为30℃。分析了垂直接地极降低地网环流的效果,计算结果可为特高压HGIS生产厂家提供参考。
Large amount of power loss can be caused by circulating current in UHV shells and grounding system due to its high voltage level and large capacity. Taking a certain UHV HGIS switch station as example,the circulating current value is obtained and analyzed through building a 3-D finite model of the switch station and analyzing its coupled electromagnetic field. Results of finite analysis and field-circuit coupling method are applied to calculation of circulating current and temperature rise in grounding wires. Calculation results show that： the maximum of the shell circulating current is about 3 500 A with the rated current 6 300 A on the bus. Adoption of bi-layer grounding network can limit the circulating current value in the main grounding network to 20 A,while 700 A in the sub-grounding network. But this method proves no affection on the short wire current. How the vertical grounding electrode deep acts on the circulating current value in grounding network is analyzed as well. The results can act as reference for the UHV HGIS manufacturers.
出处
《东北电力技术》
2017年第9期17-22,共6页
Northeast Electric Power Technology
