单芯电力电缆护层绝缘水平下降对保护器额定电压的影响  

Influence of Single-core Power Cable Sheath Insulation Level Drop on the Rated Voltage of the Protector

作　　者：覃喜 周文俊 吕鸣 傅雨荷 邹国平[2] 杨仕友[2] QIN Xi;ZHOU Wenjun;LV Ming;FU Yuhe;ZOU Guoping;YANG Shiyou(Zhejiang Huayun Electric Engineering Design and Consulting Co.,Ltd.,Hangzhou 310027,China;College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江华云电力工程设计咨询有限公司,浙江杭州310027 [2]浙江大学电气工程学院,浙江杭州310027

出　　处：《电工技术》2021年第23期129-131,134,共4页Electric Engineering

基　　金：浙江华云电力工程设计咨询有限公司科技项目(编号2019C01D01P04)。

摘　　要：由于长期运行及环境变化等因素的影响,单芯电力电缆外护层绝缘水平随着运行时间的增加而普遍降低,因此需重新进行护层保护器设计和选型。电缆运行时,护层保护器需耐受在护层上产生的操作过电压,并在雷击过电压入侵时准确动作。为避免护层保护器在操作过电压作用下的误动作,便于工程应用,基于现有的高压试验数据,首先研究了电缆绝缘寿命理论曲线的绝缘水平下降规律,在此基础上修正了保护器额定电压与操作过电压的绝缘配合系数,并设计保护器选型MATLAB小程序。该研究成果具有一定的理论和工程应用价值。Due to the influence of factors such as long-term operation and environmental changes,the insulation level of the outer sheath of single-core power cables generally decreases with the increase of operating time,so it is necessary to redesign and select the sheath protector.During cable operation,the sheath protector shall withstand the operating overvoltage generated on the sheath and act accurately in case of lightning overvoltage invasion.In order to avoid the misoperation of sheath protector under operating overvoltage and facilitate engineering application,based on the existing high-voltage test data,firstly,the decline law of insulation level of cable insulation life theoretical curve is studied.On this basis,the insulation coordination coefficient of rated voltage and operating overvoltage of protector is corrected,and the MATLAB applet for protector selection is designed.The research results have certain theoretical and engineering application value.

关 键 词：单芯电力电缆 护层保护器 绝缘降低 

分 类 号：TM854[电气工程—高电压与绝缘技术]