Flashover Behavior of Cone-type Spacers with Inhomogeneous Temperature Distribution in SF_(6)/N_(2)-filled DC-GIL Under Lightning Impulse with DC Voltage Superimposed  

作　　者：Guoming Ma Hongyang Zhou Yuan Wang Hanchi Zhang Shijie Lu Youping Tu Jian Wang Chengrong Li 

机构地区：[1]State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China [2]Beijing Key Laboratory of High Voltage and EMC,North China Electric Power University,Beijing 102206,China

出　　处：《CSEE Journal of Power and Energy Systems》2020年第2期427-433,共7页中国电机工程学会电力与能源系统学报（英文）

基　　金：This work was supported in part by the National Basic Research Program of China(973 Program)(2014CB239500);Young Elite Scientists Sponsorship Program by CAST(YESS20160004);Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(Grant No.161053).

摘　　要：Before designing DC gas insulated transmission lines(GIL),the insulation characteristics of spacers under a lightning impulse(LI)voltage with a superimposed DC voltage must be clarified.Many experiments have been performed to guide the development of the DC spacer.However,the impacts of thermal stresses on their insulation performance under combined voltage are always neglected,and little attention has been given to the insulation characteristics of spacers in an eco-friendly gas filled DC-GIL.To solve these problems,an experiment setup with the abilities to load the thermal field and the DC voltage with LI voltage superimposed on the cone-type spacer are built.After that,the insulation characteristics of spacers under the combined voltage of DC with lightning impulse at 0.1 MPa SF_(6)/N_(2) gas mixtures are investigated,under different thermal stress conditions.The experiment’s results indicate that:1)The flashover voltage of spacers under the same polarity superimposed voltages is slightly higher than that under LI alone.Conversely,the flashover voltage under reverse polarity superimposed voltages is lower than that under LI alone.2)The longer the duration of the foregoing DC voltage,the differences between the flashover voltage under superposed voltage and that under LI alone are larger.3)The combined flashover voltages are reduced under thermal stress.To ensure the insulation performance of newly designed DC spacers,the insulation test is suggested to be applied under thermal stress and combined voltage of the DC with lightning impulse,especially for superimposed reverse polarity.

关 键 词：Cone-type spacer DC GIL surface charge thermal stress volume conductivity 

分 类 号：TM714.2[电气工程—电力系统及自动化]