电工技术学报  2023, Vol. 38 Issue (23): 6461-6470    DOI: 10.19595/j.cnki.1000-6753.tces.221644
高电压与放电 |
不均匀积污绝缘子雷电冲击闪络特性
蒋兴良1, 王茂政1, 袁一钧2, 张志劲1, 陈宇1
1.重庆大学雪峰山能源装备安全国家野外科学观测研究站 重庆 400044;
2.国网湖南省电力有限公司电力科学研究院 长沙 410007
Lightning Impulse Flashover Performance of Non-Uniform Pollution Insulators
Jiang Xingliang1, Wang Maozheng1, Yuan Yijun2, Zhang Zhijin1, Chen Yu1
1. Xuefeng Mountain Energy Equipment Safety National Observation and Research Station of Chongqing University Chongqing 400044 China;
2. State Grid Hunan Electric Power Company Limited Research Institute Changsha 410007 China
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摘要 自然条件下,绝缘子呈现不均匀积污状态,对绝缘子的雷电冲击闪络电压有较大影响。为此,该文以XP-70和LXY-70绝缘子为研究对象,在重庆大学雪峰山能源装备安全国家野外科学观测研究站进行不均匀积污绝缘子在预加交流电压后的雷电冲击闪络试验,并对其闪络特性进行分析。试验结果表明,在不均匀积污条件下存在非常明显的极性效应,且出现了极性反转现象。在相同等值附盐密度(ESDD)下,随着不均匀积污比(T/B)的减小,预加交流电压作用下的泄漏电流随之减小,而绝缘子串的闪络电压呈现上升趋势。此外,通过超高速摄像机拍摄的不均匀积污绝缘子的闪络过程发现,不均匀积污绝缘子下表面会率先形成非连续的局部电弧,局部电弧沿面快速发展最终导致闪络。最后,建立了普通瓷绝缘子和玻璃绝缘子的雷电冲击闪络电压梯度方程,并对其进行验证,结果表明计算值与试验值的相对误差在±6.56%之内。
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蒋兴良
王茂政
袁一钧
张志劲
陈宇
关键词 不均匀积污雷电冲击闪络电压梯度预加交流电压    
Abstract:Flashover of pollution insulators is a serious threat to the safe operation of transmission lines, and most existing researches are limited to the AC and DC flashover performance of non-uniform pollution insulators and the lightning impulse flashover performance of uniform pollution insulators. The lightning resistance of pollution insulators is lower than that of clean insulators, and under natural conditions, insulators show non-uniform pollution state, which exacerbates the electric field distortion and has a greater impact on the flashover voltage. To address the shortcomings of existing researches, this paper carries out lightning impulse flashover tests on 7 pieces of XP-70 and LXY-70 suspension insulators with non-uniform pollution top and bottom surfaces after preloading AC voltage in Xuefeng Mountain Energy Equipment Safety National Observation and Research Station of Chongqing University.
Firstly, the inert and conductive components of pollution are simulated using diatomaceous earth and sodium chloride, and the ratio of non-soluble deposit density (NSDD) to equivalent salt deposit density (ESDD) on the surface of insulators is maintained at 6. The top and bottom surfaces of insulators are coated separately using a quantitative painting method, and different non-uniform pollution accumulation ratios (T/B) are simulated by keeping the total amount of sodium chloride on the surface of insulators constant and only changing the salt density ratio on the top and bottom surfaces of insulators. After the test arrangements are complete, the lightning impulse circuit switch is disconnected, and the AC circuit switch is closed and preloading AC 70 kV voltage to insulators. After 3 minutes of preloading AC voltage, the AC circuit switch is disconnected and the lightning impulse circuit switch is immediately closed. The up and down method is used as the test voltage addition method, and the voltage step is set at about 3% of the expected lightning impulse flashover voltage U50% and 20 valid tests are conducted on the same sample.
The results show a very obvious polarity effect and a polarity reversal phenomenon. When the T/B is 1:1, the negative polarity lightning impulse flashover voltage of insulators is higher than the positive polarity lightning impulse flashover voltage; when the T/B is 1:8 and 1:15, the positive polarity lightning impulse flashover voltage of insulators is higher than the negative polarity lightning impulse flashover voltage. At the same value of ESDD, as T/B decreases, the leakage current under preloading AC voltage is also reduced, while the lightning impulse flashover voltage of insulators shows an increasing trend, and the positive polarity lightning impulse flashover voltage of insulators increases more than the negative polarity lightning impulse flashover voltage.
In addition, an ultra-high speed camera with an exposure time of 10 μs, a frame rate of 90 000 and an exposure of 5 is used to film the flashover process of the XP-70 insulators at an ESDD of 0.08 mg/cm2 and a T/B of 1:8. The filmed flashover process shows that many discontinuous local arcs exist on the surface of insulators before flashover and the discontinuous local arcs are all formed on the bottom surface of insulators. As time progresses, the stable local arcs develop rapidly along the surface of insulators and eventually lead to a flashover. Finally, according to the form of lightning impulse flashover of non-uniform pollution insulators, the equations of lightning impulse flashover voltage gradient for ordinary porcelain and glass suspension insulators are established and verified, with the verification results showing that the relative errors between the calculated values and the test values of XP-100, XP-120, LXY-100 and LXY-120 insulators are within ±6.56%.
Key wordsNon-uniform pollution    lightning impulse    flashover voltage gradient    preloading AC voltage   
收稿日期: 2022-08-29     
PACS: TM216  
基金资助:国家自然科学基金重点项目资助(51637002)
通讯作者: 王茂政 男,1997年生,博士研究生,研究方向为复杂大气环境下输电线路外绝缘及防护。E-mail:wangmaozheng@cqu.edu.cn   
作者简介: 蒋兴良 男,1961年生,教授,博士生导师,研究方向为输电线路覆冰灾害防护与高电压绝缘技术。E-mail:xljiang@cqu.edu.cn
引用本文:   
蒋兴良, 王茂政, 袁一钧, 张志劲, 陈宇. 不均匀积污绝缘子雷电冲击闪络特性[J]. 电工技术学报, 2023, 38(23): 6461-6470. Jiang Xingliang, Wang Maozheng, Yuan Yijun, Zhang Zhijin, Chen Yu. Lightning Impulse Flashover Performance of Non-Uniform Pollution Insulators. Transactions of China Electrotechnical Society, 2023, 38(23): 6461-6470.
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