高频方波电场-温度场作用下环氧树脂介电特性劣化协同效应  

Synergistic Effect of Epoxy Resin Dielectric Properties Deterioration Under the Action of High-frequency Square Wave Electric Field-temperature Field

作　　者：司剑 文韬 赵毅 马波 黄辛毅 孙绪乾 SI Jian;WEN Tao;ZHAO Yi;MA Bo;HUANG Xinyi;SUN Xuqian(School of Electrical and Automation Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学电气与自动化工程学院,合肥230009

出　　处：《高电压技术》2024年第9期4007-4018,共12页High Voltage Engineering

基　　金：国家重点研发计划(2022YFB2404103)。

摘　　要：高频变压器环氧树脂固封绝缘系统长期承受高频方波电压应力和热应力,环氧树脂在高频方波电压应力和热应力下的绝缘性能劣化严重制约着高频变压器的运行可靠性。以往研究多在交流正弦电场与温度场作用下对环氧树脂介电特性进行分析,缺乏环氧树脂在高频方波电场-温度场作用下介电特性变化的研究。搭建高频方波电压与温度联合老化实验平台,对不同老化电场强度、温度条件下环氧树脂样片进行介电特性研究,并将电热联合老化结果与单独热老化、电老化结果进行对比分析。实验结果表明,电热联合老化对环氧树脂介电特性的影响更显著,且大于电、热的叠加作用,即电热联合老化过程中存在着协同效应。通过构建环氧树脂在高频方波电压下的极化损耗计算模型,阐明了在高频方波电场作用下,由环氧树脂极化损耗引起的样片温度升高是加剧环氧树脂介电特性劣化的重要原因。该研究结果可为高频变压器绝缘状态评估提供参考。The epoxy resin sealing insulation in high-frequency transformers has been exposed to prolonged high-frequency square wave voltage stress and thermal stress.The deterioration of the insulation performance within the epoxy resin under these conditions significantly hampers the operational reliability of the transformers.Previous studies primarily focused on analyzing the dielectric properties of epoxy resins under alternating current sinusoidal electric fields and temperature fields,however,the studies on the change of dielectric properties of epoxy resin under the action of high-frequency square-wave electric field and temperature field are rarely available in the literature.In this paper,a high-frequency square-wave voltage and temperature joint aging experimental platform is set up to study the dielectric properties of epoxy resin samples under different aging electric field strengths and temperatures,and the results of the combined electro-thermal aging are compared with the results of the separate thermal aging and electric aging.The ex-perimental results show that the effect of electro-thermal joint aging on the dielectric properties of epoxy resin is more significant and greater than the superimposed effect of electricity and heat,indicating there is a synergistic effect in the process of electro-thermal joint aging.By constructing the polarization loss simulation model of epoxy resin under high-frequency square-wave voltage,it is clarified that the temperature increase of the sample caused by the polarization loss of epoxy resin under the action of high-frequency square-wave electric field is an important reason to aggravate the deterioration of the dielectric properties of epoxy resin.The results of this study can provide a reference for the evaluation of the insulation state of high-frequency transformers.

关 键 词：环氧树脂 方波电压 介电特性 极化损耗 协同效应 

分 类 号：TM433[电气工程—电器]