1000kV柱式CVT的设计要点及检测

1000kV柱式电容式电压互感器(CVT)是我国晋东南—南阳—荆门1000kV特高压交流试验示范工程的重要设备,它的设计不仅要考虑特高压绝缘问题,同时要兼顾误差特性、安装特性等。根据我国1000kV特高压输电工程的需要,在对比柱式结构CVT、SF6气体绝缘电磁式电压互感器、电子式电压互感器(EVT)优缺点基础上,对我国1000kV交流特高压工程用电压互感器进行了选型;分析了1000kV柱式CVT的设计原理、参数选择、结构要求、现场检测方法及附加误差,同时提出1000kV标准电压互感器的结构设计。1000kV柱式CVT的试制成功证明,1000kVCVT符合对1000kV特高压电网电压测量和保护的要求,为我国晋东南-南阳-荆门1000kV特高压交流试验示范工程的顺利进行提供了保障。

Design Points and Test of 1 000 kV Column-type Capacitive Voltage Transformer

There are 18 column-type capacitive voltage transformers in 1 000 kV UHVAC pilot project(Jindongnan-Nanyang-Jingmen).For 1 000 kV CVT design,not only insulation tolerance,but also error characteristics,installation characteristics must be considered.This paper analyzes the advantages and disadvantages of column-type capacitive voltage transformer(column-type CVT),SF6 gas insulated voltage transformer(VT)and electronic voltage transformer(EVT),and then chooses the proper one which is suit for UHVAC grid of China,and introduces the design principle and preferences,including principle circuit,output capacity,coupling capacitor,output voltage of capacitance divider,intermediate voltage,intermediate capacitance of capacitance divider,dielectric level of electromagnetic unit,availability of ferromagnetic resonance equivalent circuit,structure request,including overall structure,electromagnetic unit structure and grading structure,field test method and additional errors caused by high-voltage leading wire,temperature and frequency.Meanwhile,this paper puts forward a structure design of 1 000 kV standard VT.The trial-manufacture of 1 000 kV column-type CVT proves that 1 000 kV CVT can meet the demands of measurement and protection for 1 000 kV UVTAC grid,and the results lay a solid foundation for the first scheme of 1 000 kV UHVAC pilot project(Jindongnan-Nanyang-Jingmen).