交流叠加冲击电压下环氧绝缘内部气隙局部放电特性  

PD Characteristics of Void in Epoxy Insulation under AC and Impulse Superimposed Voltage

作　　者：何聪 张炜 李良书 黄继军 李军浩[2] HE Cong;ZHANG Wei;LI Liangshu;HUANG Jijun;LI Junhao(State Grid Shaanxi Electric Power Company Limited,Xi’an 710048,Shaanxi,China;State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi,China)

机构地区：[1]国网陕西省电力有限公司,陕西西安710048 [2]西安交通大学电力设备电气绝缘国家重点实验室,陕西西安710049

出　　处：《电网与清洁能源》2023年第3期33-39,47,共8页Power System and Clean Energy

基　　金：国家自然科学基金项目(51877169)。

摘　　要：GIS设备在运行过程中时常会受到各类瞬态冲击的作用,交流叠加冲击将严重威胁设备的绝缘安全。为掌握交流叠加冲击电压下环氧绝缘子的绝缘特性,构建叠加电压实验平台,研究分析SF6中环氧绝缘内部气隙缺陷在工频交流与操作冲击叠加电压下的局部放电特性,记录冲击过后的局部放电时域波形,统计最大放电量与放电次数,总结分析交流电压不同相位叠加冲击时的局部放电激发特性和规律。结果表明,操作冲击电压的叠加相位对绝缘内部气隙缺陷的局部放电起始特性具有显著的影响。在交流电压45°、90°与135°叠加操作冲击时可激发气隙缺陷发生局部放电,但放电剧烈程度存在差异;冲击叠加在其他相位时未能激发环氧绝缘内部气隙缺陷产生局部放电;冲击所激发的局部放电持续时间均不超过5个工频周期。Gas insulated switchgear(GIS)is often subjected to various transient impulses during operation,and the AC superimposed impulse seriously threatens the insulation safety.In order to grasp the insulation characteristics of epoxy insulators under the AC and impulse superimposed voltage,a joint voltage test platform is constructed to experimentally investigate the partial discharge(PD)characteristics of the void defect of epoxy insulation under the superimposed voltages in SF6 gas.The PD signal is recorded,the maximum discharge and the number of PD pulses is counted,and the PD excitation characteristics of different phase superposition impulses are summarized and analyzed.The results show that the impulse superposition phase has a significant effect on the PD inception characteristics of the void defect.The PD of the void defect can be excited when the switching impulse is superimposed on 45°,90°and 135°of AC voltage,but the discharge intensity is different.PD is not excited when the switching impulse is superimposed on other phases.The PD duration are all no more than five power frequency cycles.

关 键 词：环氧绝缘 气隙缺陷 交流叠加冲击 局部放电 

分 类 号：TM85[电气工程—高电压与绝缘技术]