电工技术学报2024，Vol.39Issue(13)：4116-4126,11.DOI:10.19595/j.cnki.1000-6753.tces.230770
交流电压下伞型结构对染污绝缘子电弧路径及绝缘性能的影响
Influence of Umbrella Structure on the Arc Path and Insulating Properties of Contaminated Insulators under AC Voltage
摘要
Abstract
Insulators play a crucial role in power systems as they provide support and insulation for power lines.While insulators are generally resistant to internal breakdown,they are more susceptible to flashovers on their external surfaces.In areas with heavy pollution,the presence of a water film on the insulator's surface increases the likelihood of pollution flashover.Increasing the creepage distance is the most effective method for enhancing the flashover voltage of insulators.However,increasing the creepage distance within a limited space can complicate the insulator's structure.Some insulators feature more umbrella ribs internally,which creates a complex and narrow space that facilitates arc propagation through jumping.Interestingly,larger creepage distances can lead to a decrease in the insulator's flashover voltage.To investigate this phenomenon,the paper focuses on analyzing the path of arc propagation,statistical probability distribution,and the relationship between arc length and flashover voltage. Firstly,a glass insulator test model was designed to replicate the actual insulator structure.The test model took into consideration three key structural parameters of the insulator:umbrella extension,umbrella spacing,and maximum umbrella rib length.Glass panels were used as a substitute for the real insulator's umbrella skirts and ribs.By adjusting the length and width of the glass panels,it was possible to create test models that mimicked different insulator structures accurately. Secondly,a test platform for arc path shooting was constructed.The arc path shooting platform comprised a pressurized platform designed to meet the International Electrotechnical Commission(IEC)flashover test standard and a high-speed camera.The insulator test model was subjected to multiple flashover tests,which involved smearing and voltage application following the procedures outlined in the IEC standards. Finally,the high-speed camera was carefully positioned to align with the vertical plane between the insulator umbrellas.This enabled the camera to capture the path of the arc as it propagated across the insulator.The recorded images were subsequently processed using image processing techniques,and the arc paths were precisely segmented using mesh segmentation algorithms.This method facilitated the efficient and accurate acquisition of a substantial volume of arc path data,enabling the generation of comprehensive arc path summary charts.By employing this approach,the researchers were able to gather a significant amount of data on the arc propagation patterns across the insulator.This allowed for detailed analysis and evaluation of the influence of different structural parameters on insulation performance. Two coefficient representations are proposed to evaluate insulator structures.These coefficients include the depth coefficient of the inter-umbrella space depth,which is calculated by dividing the umbrella spacing by the umbrella extension,and the maximum umbrella rib structure coefficient,obtained by dividing the umbrella rib length by the umbrella spacing.The findings of the study indicate that the arc paths between insulator umbrellas mainly fall into two categories:cling-surface arcs and air-jump arcs.The probability of these different arc path formations is influenced by the structural parameters of the insulator.Based on the research results,it is recommended to maintain an inter-umbrella space depth coefficient(umbrella spacing/umbrella extension)within the range of 0.8～1.2.A smaller coefficient leads to a higher probability of air-jump arc development,whereas a larger coefficient implies under-utilization of the available space.Further more,the study suggests a reference range of 0.4～0.5 for the maximum umbrella rib structure coefficient(umbrella rib length/umbrella spacing).When this coefficient exceeds the recommended range,the creepage distance is not optimally utilized,resulting in reduced flashover voltage.The paper highlights that positioning the maximum umbrella rib at the edge of the umbrella skirt results in lower flashover voltage compared to when it is placed inside the skirt.关键词
交流电压/绝缘子/污秽闪络/局部电弧/闪络电压Key words
AC voltage/insulator/pollution flashover/partial arc/flashover voltage分类
信息技术与安全科学引用本文复制引用
宋治波,杨昊,申巍,肖康泰,薛建鹏..交流电压下伞型结构对染污绝缘子电弧路径及绝缘性能的影响[J].电工技术学报,2024,39(13):4116-4126,11.基金项目
国家自然科学基金项目(52007138)和国网陕西省电力有限公司科技项目(5226KY22001G)资助. （52007138）
