高海拔条件下550kV空气绝缘隔离开关均压装置的结构优化

Structure Optimization of Grading Device for 550 kV Air-insulated Disconnector Under High Altitude

550 kV空气绝缘隔离开关是电力系统中普遍应用的开关电器,其运行性能直接影响电力系统的安全稳定性。为合理确定GW6A-550D(W)/J4000-63型单柱双臂垂直伸缩式空气绝缘隔离开关适用于2 000 m高海拔条件下的结构形式和外形尺寸,并使其顺利通过绝缘型式试验,开展了以下研究工作:首先根据隔离开关的初步结构设计,通过高海拔修正条件下的绝缘型式试验和三维仿真电场计算,确定隔离开关发生电晕放电的具体部位;其次,针对隔离开关发生电晕放电的部位,从增加均压环、改变均压环的外径和管径进行优化,优化后的计算结果显示,隔离开关的各部位表面场强值均满足设计要求的临界击穿场强值22 kV/cm;最后,对隔离开关开展高海拔修正条件下的绝缘型式试验。研究结果表明,优化后的隔离开关满足高海拔修正条件下的绝缘型式试验要求,可为适用于高海拔条件下的隔离开关结构参数设计提供参考。

550 kV air-insulated disconnector is a commonly used switching device in the electrical system,and its operating performance directly affects safety and stability of the power system and even personal safety.In order to reasonably determine the structure and appearance dimensions of GW6A-550D(W)/J4000-63 single-column double-arm vertical pantograph air-insulated disconnector for high altitude conditions at 2000 meters and keep it successfully pass the insulation type tests,the following research work is carried out.Firstly,according to the preliminary structural design,the specific position of corona discharge of the disconnector is determined through the type test and the calculation of the 3-D finite element method.Secondly,as for the position with occurrence of corona discharge in the disconnector,the optimization is performed by adding grading ring,changing external diameter and tube diameter of grading ring.The calculation result after the optimization shows that the surface field strength of each position of disconnector meets the critical breakdown field strength of 22 kV/cm required by the design.Finally,the insulation type test of the disconnector at high altitude is performed.The research result shows that the optimized disconnector can meet the requirements of insulation type tests under high altitude,and can provide reference for the design of the structural parameters of the disconnector for high altitude application.