多层环绕油纸绝缘中水分迁移特性及温度影响研究

发布时间：2018-04-15 06:40

  本文选题：电容芯子 + 多层环绕油纸绝缘　； 参考：《华北电力大学(北京)》2017年硕士论文

【摘要】：外界水分入侵导致的绝缘受潮是变压器油纸绝缘套管事故频发的主要原因之一。目前现场对于套管受潮缺陷的监测存在困难,套管的受潮特性并不清晰。为了能够准确评估套管受潮状态,建立受潮缺陷与电气测量参数之间的联系,需要研究套管的受潮过程。构成变压器套管主绝缘的电容芯子属于多层环绕油纸绝缘结构,侵入套管的水分会逐渐在油纸绝缘内部进行扩散和迁移,同时迁移的方向和速率受与温度关系密切。有必要研究水分在多层环绕油纸绝缘结构中的水分迁移特性及温度影响,这对于评估油纸绝缘套管的受潮状态,实现对其受潮缺陷的监测具有重要的理论意义和工程价值。本文设计了与实际套管电容芯子相似的多层环绕油纸绝缘模型,建立了受潮特性研究平台以模拟受潮缺陷并实现温度控制,测量并分析了模型在受潮后经历不同静置时间的绝缘油和绝缘纸的含水量情况,提出了用于描述模型平均受潮程度的表征量——平均含水量和用于描述芯子模型受潮含水量分布情况的表征量——分散度。研究结果表明,室温20℃下多层环绕油纸绝缘中水分迁移具有如下特性:模型油中微水浓度在静置前期会迅速上升,在静置中后期油中微水浓度会因水分迁移入纸而逐渐下降;模型绝缘纸含水量分布具有区域特性。模型上端区域含水量分布分散性大,其余四个区域各自含水量分布均匀,区域间含水量水平差距明显;模型绝缘纸吸湿速率具有区域特性,各区域间含水量增长速率差异明显。温度对多层环绕油纸绝缘中水分迁移特性的影响包括:温度升高会改变模型油中微水浓度变化趋势,使其先上升,然后在平衡值附近波动;温度变化对模型含水量分布的区域特性基本没有影响,且各区域含水量大小排序不变;温度会改变模型整体吸湿速率数值和局部吸湿速率数值。
[Abstract]:Damp insulation caused by water invasion is one of the main reasons for frequent accidents of transformer oil-paper insulating sleeving.At present, it is difficult to monitor the dampness of casing in the field, and the moisture characteristic of casing is not clear.In order to accurately evaluate the damp state of casing and to establish the relationship between moisture imperfection and electrical measurement parameters, it is necessary to study the damp process of casing.The capacitive core which constitutes the main insulation of transformer casing belongs to the multi-layer surrounding oil-paper insulation structure. The moisture content invading the casing will gradually diffuse and migrate inside the oil-paper insulation and the direction and speed of migration are closely related to temperature.It is necessary to study the moisture migration characteristics and temperature effects in the multi-layer surrounding oil-paper insulation structure, which is of great theoretical significance and engineering value in evaluating the damp state of oil-paper insulating sleeving and realizing the monitoring of dampproof defects.In this paper, a multi-layer oil-paper insulation model, which is similar to the practical casing capacitor core, is designed, and a research platform is established to simulate the damped defects and achieve temperature control.The moisture content of insulating oil and insulating paper which experienced different static time after damp was measured and analyzed.The characterizing quantity-average moisture content used to describe the average moisture content of the model and the representation quantity-dispersion degree used to describe the distribution of moisture content in the core model were proposed.The results show that the moisture migration in multi-layer surrounding oil paper insulation at room temperature 20 鈩，

本文编号：1753000