稍不均匀电场中SF_(6)气体的低温放电特性研究  

Study on Low Temperature Discharge Characteristics of SF_(6) Gas in Slightly Inhomogeneous Electric Field

作　　者：王远东 刘海波 孟辉 郑宇 周文俊[3] 喻剑辉[3] 马晨曦 WANG Yuandong;LIU Haibo;MENG Hui;ZHENG Yu;ZHOU Wenjun;YU Jianhui;MA Chenxi(Inner Mongolia Eastern Power Limited Liability Company of State Grid,Hohhot 010000,China;Maintenance Branch of Inner Mongolia Eastern Power Limited Liability Company of State Grid,Inner Mongolia Tongliao 028000,China;School of Electrical Engineering and Automation,Wuhan University,Wuhan 430072,China)

机构地区：[1]国网内蒙古东部电力有限公司,呼和浩特010000 [2]国网内蒙古东部电力有限公司检修分公司,内蒙古通辽028000 [3]武汉大学电气与自动化学院,武汉430072

出　　处：《高压电器》2021年第4期15-20,共6页High Voltage Apparatus

基　　金：国网内蒙古东部电力有限公司科技项目(JS1900697);智能电网联合基金项目(U1966211)。

摘　　要：为掌握SF_(6)气体的低温放电特性,保证低温环境下SF_(6)气体设备的运行可靠性。文中开展了-50℃至20℃温度范围内,半球头棒板电极下SF_(6)气体的工频击穿试验。同时测量了降温过程中SF_(6)气体的气压随温度的变化。获得了稍不均匀电场中绝对气压0.7 MPa和0.5 MPa的SF_(6)气体的放电电压随温度的变化规律。发现当温度从20℃降低到-50℃时,SF_(6)气体的放电电压和气压均呈现先缓慢降低,再迅速降低趋势,放电电压下降趋势的拐点与气压下降趋势的拐点基本一致,计算发现该拐点温度等于SF_(6)气体的液化温度。利用气体放电理论解释了试验现象,指出SF_(6)气体液化使气体密度降低从而导致其放电电压降低。进一步计算了SF_(6)气体的液化温度与气压的关系,为SF_(6)气体设备在低温下的安全运行提供了参考。In this paper,the power frequency breakdown test of SF_(6) gas at hemispherical rod plate electrode at the temperature ranged from-50 ℃ to 20 ℃ is performed for the purpose of mastering the low temperature discharge characteristics of SF_(6) gas and assuring the operation reliability of SF_(6) gas equipment in low temperature environment. At the same time,the variation of SF_(6) gas pressure with temperature is measured. The variation law of discharge voltage of SF_(6) gas at absolute pressure at 0.7 MPa and 0.5 MPa in the slightly inhomogeneous electric field with temperature is obtained. It is found that when the temperature decreases from 20 ℃ to-50 ℃,the discharge voltage and pressure of SF_(6) gas show the tendency of initially slow decrease and then fast decrease. The inflection of discharge voltage decrease tendency is basically identical to that of gas pressure decrease tendency. It is found by calculation that the temperature of the inflection point is equal to the liquefaction temperature of SF_(6) gas. The test phenomena are explained by gas discharge theory. It is pointed out that the density of SF_(6) gas is reduced by its liquefaction,thus causing the reduction of its discharge voltage. Furthermore,the relationship between the liquefying temperature and the pressure of SF_(6) gas is calculated,which provides a reference for the safe operation of SF_(6) gas equipment at low temperature.

关 键 词：SF_(6) 电气设备 气体绝缘 低温放电 液化温度 

分 类 号：TM213[一般工业技术—材料科学与工程]