基于静电场分析的固封极柱局部放电研究  

Research on Embedded Pole Partial Discharge Based on Electrostatic Field Analysis

作　　者：张文凯[1,2] 吴小钊 郑亚利[3] 李鹏[1,2] 

机构地区：[1]许继集团有限公司,许昌461000 [2]许昌许继德理施尔电气有限公司,许昌461000 [3]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高电压技术》2015年第11期3858-3865,共8页High Voltage Engineering

基　　金：国家电网公司科技项目(SGKJ[2014]1159)~~

摘　　要：基于静电场分析研究固封极柱局部放电对绝缘结构的设计及优化过程具有重要的意义。为此,运用静电场分析的方法得到12 kV固封极柱的电场分布云图,并提取电场较为集中区域如接地屏蔽网、螺栓附近空气域的电场分布,同时参照固封极柱组合绝缘中各绝缘介质的介电强度,指出螺栓附近空气域的电场强度超过空气的介电强度致使此区域局部放电超标。然后依据静电场组合绝缘理论,在不变更模具的前提下,提出在固封极柱螺栓固定孔与软包硅橡胶之间增设法兰屏蔽罩以降低螺栓附近空气域场强的方法。通过静电场分析得出优化后螺栓附近空气域的最大场强由5.8 MV/m降至0.32 MV/m,验证了此优化方法在理论上的可行性。局部放电测试试验结果表明,优化后的平均熄灭电压由6.5 kV提高至14.7 kV,验证了静电场分析方法可用于固封极柱局部放电的研究中,同时也确定了优化方案在工程应用上的可行性。It is of great significance for the design and optimization of insulation structures to investigate partial dis- charges in embedded poles based on electrostatic field analysis. We obtained the electric field distribution of 12 kV embedded poles using electrostaticfield analysis, as well as the electric field distribution of some mostly concerned areas such as earth network and the air domain nearby bolts. According to the dielectric strength of the insulating medium in embedded pole, it is obvious that the field intensity of air domain near bolt is larger than the dielectric strength of air, re- suiting in above-norm partial discharges. Then an optimization model is proposed based on the composite insulation theory without changing the mould. The optimized model is advanced by adding flange shields between bolt holes and soft silicone rubber package and is verified by electrostatic field simulation, indicating that the maximum field strength of the air domain near bolt decreases from 5.8 MV/m to 0.32 MV/m. Finally, partial discharge tests are carried out, showing that the average extinction voltage after optimization increases from 6.5 kV to 14.7 kV. Therefore, it is verified that the electrostatic filed analysis can be applied to research partial discharges in embedded pole, and the feasibility of the opti- mization measures in engineering applications can be confirmed.

关 键 词：局部放电 绝缘结构 固封极柱 静电场分析 电场强度 组合绝缘 

分 类 号：TM595[电气工程—电器] O441.1[理学—电磁学]