预紧力对变压器油纸绝缘热老化影响研究  

Study on the influence of preload on the thermal aging of transformer oil-paper insulation

作　　者：刘骥[1] 王凡予 LIU Ji;WANG Fan-yu(Key Laboratory of Engineering Dielectrics and Application of Ministry of Education,Harbin University of Science and Technology,Harbin 150080,China)

机构地区：[1]哈尔滨理工大学工程电介质及其应用教育部重点实验室,哈尔滨150080

出　　处：《电机与控制学报》2020年第6期127-134,共8页Electric Machines and Control

基　　金：国家自然科学基金青年基金项目(51407051)。

摘　　要：为了研究预紧力对变压器油纸绝缘热老化的影响,采用模拟变压器绕组压紧工作状态的方法,建立饼间绝缘垫块径向单元试验模型,搭建试验系统,进行预紧力对油纸绝缘热老化影响的试验研究。并给出在130℃试验温度,不同预紧力作用下,每隔15 d提取试验试样的测试结果。研究发现,随着预紧力的增加,试样扫描电镜纤维结构有变窄趋势、聚合度数值降低幅度有减弱趋势、频域介电谱坐标曲线有平移趋势。依据晶体学和自由体积基本理论,构建绝缘纸力学模型,研究油纸绝缘热老化机理,分析水分和小分子酸对油纸绝缘热老化的作用,发现预紧力作用使变压器油纸绝缘热老化相对减弱。In order to study the effect of preload on the thermal aging of transformer oil-paper insulation,this paper uses the method of simulating the working state of the transformer winding compaction.A radial unit test model of the inter-insulation insulation pad was established,a test system was built,and an experimental study on the effect of pretension on the thermal aging of oil-paper insulation was carried out.The test results of extracting tested samples every 15 d under the test temperature of 130℃and different preload were given.The study found that with the increase of the preload,the fiber structure of the sample scanning electron microscope has a tendency to narrow,the degree of polymerization value reduction has a tendency to weaken,and the frequency domain dielectric spectrum coordinate curve has a tendency to shift.Based on the basic theory of crystallography and free volume,a mechanical model of insulation paper was constructed to study the thermal aging mechanism of oil-paper insulation.The effect of moisture and small molecular acids on the thermal aging of oil-paper insulation was analyzed.It was found that the effect of pretension on the thermal aging of oil-paper insulation of transformers was relatively weakened.

关 键 词：变压器 油纸绝缘 预紧力 老化 微观形貌 介质损耗 

分 类 号：TM85[电气工程—高电压与绝缘技术]