特高压直流GIL运行可靠性设计与研究  

Design and Research on Operation Reliability of UHV DC GIL

作　　者：黎斌 刘琳 梁作栋 李丽娜 曹少华 梁芳蔚 李传扬[2] 何金良[2] 张长虹 LI Bin;LIU Lin;LIANG Zuodong;LI Lina;CAO Shaohua;LIANG Fangwei;LI Chuanyang;HE Jinliang;ZHANG Changhong(Guangdong Power Grid Limited Liability Electric Power Science Research Institute,Guangzhou 510080,China;Tsinghua University,Beijing 100084,China;Pinggao Group Co.,Ltd.,Henan Pingdingshan 467000,China;Shandong Taikai High Voltage Switchgear Co.,Ltd.,Shandong Tai’an 271000,China;UHV Transmission Co.,Ltd.,China Southern Power Grid,Guangzhou 540610,China)

机构地区：[1]广东电网有限公司电力科学研究院,广州510080 [2]清华大学,北京100084 [3]平高集团有限公司,河南平顶山467000 [4]山东泰开高压开关有限公司,山东泰安271000 [5]南方电网超高压输电公司,广州540610

出　　处：《高压电器》2024年第3期69-79,共11页High Voltage Apparatus

基　　金：国家自然科学基金(52307174)。

摘　　要：特高压直流GIL运行可靠性取决于内绝缘设计的可靠性。此外,导电元件直流电流密度的取值、弹簧触头的定位设计、GIL各元件中的绝缘件与金具连接处的楔形气隙的处理以及母线中支撑件的结构设计细节,都会对产品运行可靠性产生重大影响,不能忽视。对于运行环境十分严酷的UHV DC GIL为保证内绝缘工作可靠性和减少气体维护工作量,文中还提出了高气密性结构设计。为适应-50℃低温运行要求,产品选用了液化温度很低的N_(2)/SF_(6)混合气体,对两种气体的配比,压力特性和绝缘特性进行了讨论与计算。还有产品的局放、气体密度及微水含量的监视系统的可靠性设计,都会对产品运行可靠性产生直接影响。文中对上述问题的研究成果作了介绍,可供高压直流产品设计使用。对其中未解的新技术如基于冷镜露点测试原理、微机电技术制作的智能气体湿度和密度监测装置、高压直流复合绝缘套管伞面局放起始场强提出了研究方案。文中提出的诸多GIL运行可靠性设计要点,对于其他超/特高压直流气体绝缘电器可参考选用。The operational reliability of ultra-high voltage DC GIL depends on the reliability of the internal insula-tion design.In addition,such issues as selection of DC current density of conductive element,the positioning de-sign of spring contacts,the treatment of wedge-shaped air gaps at the connection between insulation part and fitting in GIL components as well as the structural design details of support components in the busbar will have a signifi-cant influence on the operation reliability of product and cannot be ignored.For UHV DC GIL operating in a very harsh environment,a high airtightness structural design is proposed in this paper in order to assure the reliability of internal insulation work and reduce gas maintenance work.To meet the requirements of low temperature operation at-50℃,N_(2)/SF_(6) gas mixture with very low liquefaction temperature is selected for the product.The ratio,pressure characteristics and insulation characteristics of the two gases are discussed and calculated.The reliability design of the monitoring system for partial discharge,gas density,and micro water content of the product will also affect di-rectly the operational reliability of the product.The research results of the above issues are introduced in this pa-per,which can be used for the design of high-voltage DC products.A research plan is proposed for such unsolved new technologies as intelligent gas humidity and density monitoring devices based on the principle of cold mirror dew point testing and microelectromechanical technology as well as the initial field strength of partial discharge on the umbrella surface of high-voltage DC composite insulation sleeves.The multiple reliability design points for GIL operation proposed in this paper can be used as reference for other ultra-high voltage DC gas insulated apparatus.

关 键 词：电流密度 弹簧触头定位 楔形气隙 高气密性设计 局放微水监测预警新技术 

分 类 号：TM721.1[电气工程—电力系统及自动化]