不同因素对变压器绝缘垫块热老化特性的影响研究  

Influence of different factors on thermal ageing characteristics of transformer insulating pads

作　　者：刘云鹏[1] 严才鑫 王博闻[1] 周旭东 LIU Yunpeng;YAN Caixin;WANG Bowen;ZHOU Xudong(Hebei Provincial Key Laboratory of Power Transmission Equipment Security Defense,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学河北省输变电设备安全防御重点实验室,河北保定071003

出　　处：《绝缘材料》2023年第4期52-59,共8页Insulating Materials

基　　金：国家电网有限公司科技项目(5200-201955095A-0-0-00)。

摘　　要：为了探究绕组预紧力对绝缘垫块热老化特性的影响,对4组绝缘垫块分别施加0、200、500、1000 N预紧力后进行135℃加速热老化试验并测试绝缘垫块的力学特性。同时,为了模拟绝缘垫块在实际工况中因受绕组振动影响而发生机械老化,在对绝缘垫块施加200 N预紧力进行加速热老化的同时对其施加幅值为5 N、频率为2 Hz的正弦循环机械载荷。结果表明:热老化使0 N预紧力下绝缘垫块的应力-应变曲线逐渐右移,弹性模量逐渐减小,在135℃下加速老化336 h,绝缘垫块的弹性模量下降为新垫块的79.935%;施加预紧力对绝缘垫块的热老化有减缓作用,预紧力越大,绝缘垫块的老化速率和老化程度越低;施加循环机械载荷会加速绝缘垫块的老化。研究成果对绝缘垫块老化和变压器振动研究有一定的参考和实际应用价值。In order to study the effect of winding preload on thermal ageing characteristics of insulating pads,four groups of insulating pads were conducted accelerated thermal ageing tests at 135℃after appling 0,200,500,and 1000 N of preload,respectively,and the mechanical properties of insulating pads were tested.At the same time,in order to simulate the mechanical ageing of insulating pad under the influence of winding vibration in the actual working condition,a sinusoidal cyclic mechanical load with 5 N of amplitude and 2 Hz was applied on the accelerated thermal ageing of insulating pad with 200 N of preloading force.The results show that that thermal ageing causes the stress-strain curve of insulating pad gradually shift to the right under 0 N preload,and its elastic modulus decreases gradually.The elastic modulus of insulating pad decreases to 79.935%of the new insulating pad after accelerated ageing for 336 h at 135℃.Applying preloading force can slow down the thermal ageing of insulating pad,and the greater the preloading force,the lower the ageing rate and ageing degree of insulating pad.But applying cyclic mechanical load will accelerate the ageing of insulating pad.The research results have certain reference and practical application value for the research of insulation pad ageing and transformer vibration.

关 键 词：绝缘垫块 热老化 影响因素 力学性能 

分 类 号：TM215[一般工业技术—材料科学与工程]