40.5 kV铠装式金属封闭开关柜在高海拔电网使用中绝缘加强的改造实践

Retrofitting Practice of Strengthening Insulation for 40.5 kV Metal-clad Switchgears in Power Grid at High Altitude

针对标准配置的普通40.5 kV铠装式金属封闭开关柜在高海拔电网使用中绝缘强度不足的问题,以UniGear type ZS3.2型铠装式金属封闭开关柜为例,通过工频耐压试验和雷电冲击耐压试验,查找出绝缘缺陷,对电缆室、断路器室和母线室相关部位做了7项结构改进,对元器件进行添加或调整,还采取了均匀电场的措施,使之形成了可靠的复合绝缘,以保证良好的电气性能。并从中归纳出一套针对客户需求进行设计、改进、试验和生产的技术改造方案。

In view of lower insulation intensity of 40.5 kV metal-clad switchgears adopted in power grid at high altitude, taking UniGear Type ZS3.2 metal-clad switchgears as an example, hased on the power frequency voltage withstanding test and lightning impulse voltage withstanding test, the insulation defect is found out. Seven structure modifications or improvement are made on related position of cable room, circuit hreaker room and hus room, the components＇s position and quantity are adjust, as well as the necessary measures to make the electrical field distrihuting more uniform are adopted, which forms a more reliable composite insulation to ensure high electrical performance. Finally, this paper summarizes an integrated plan of technical transformation, which carries out the design, improving, testing and production according to customer＇s demands.