摘要
大型发电机定子线棒主绝缘受潮是导致电机绝缘受损的重要因素之一,为探究环境湿度对电机主绝缘特性的影响,制作了不同厚度的绝缘试样,测试老化前后绝缘试样在不同环境湿度下受潮后的介质损耗特性。提出采用测试频域段的介质损耗因数积分值作为绝缘状态评估的特征参量,同时研究试样绝缘厚度和受潮程度对频域介电谱和频域介质损耗因数积分谱的影响和变化规律。结果表明:老化不会对绝缘受潮的介质损耗特性带来影响;随着频率升高,定子线棒绝缘的介质损耗因数逐渐降低;绝缘受潮程度较低时介质损耗因数曲线随频率增大具有相似的变化趋势;介质损耗因数积分值和频率的关系曲线具有饱和性。10-3 Hz处的介质损耗因数积分值与湿度具有线性相关;从理论上分析,厚度对介质损耗特性没有影响,但受限于制作工艺,试样内部空气无法完全排除,随着厚度增加介质损耗因数下降。
The main insulation of stator bar for large electric generator being moistened is one of the most important factors leading to the insulation damage in motors.In order to study the effect of ambient humidity on the properties of main insulation in motors,we made insulation samples with different thickness,and tested the dielectric loss characteristics of the insulation samples before and after ageing moistened in different environmental humidity.It is proposed to use the integral value of dielectric loss factor as a characteristic parameter for evaluating the insulation state,and the influence and variation of insulation thickness and moistened degree on the frequency domain dielectric spectrum and the frequency domain dielectric loss factor integral spectrum were studied.The results show that ageing has no effect on the dielectric loss characteristics of the moistened insulation.With the increase of frequency,the dielectric loss factor of the stator bar insulation decreases gradually.When the moistened degree is low,the dielectric loss factor curves show the similar variation trend with the increase of frequency.The curve of dielectric loss factor integral value and frequency shows a saturated trend.The integrated value of the dielectric loss at 10-3 Hz has a linear correlation with humidity.Theoretically,the thickness of dielectric has no effect on its dielectric loss characteristics.However,limited by the manufacturing process,the air inside dielectrics cannot be completely excluded,which results in the decrease of dielectric loss factor with the increase of thickness.
作者
韩英喆
王安东
孙福春
王继豪
刘骥
HAN Yingzhe;WANG Andong;SUN Fuchun;WANG Jihao;LIU Ji(Key Laboratory of Engineering Dielectric and Its Application,Ministry of Education,Harbin University of Science and Technology,Harbin 150080,China;State Grid Shandong Electric Power Company Electric Power Research Institute,Jinan 250002,China)
出处
《绝缘材料》
CAS
北大核心
2020年第10期103-107,共5页
Insulating Materials
基金
国网山东省电力公司科技项目(52062617002S)。
关键词
频域介电谱
介质损耗因数积分谱
环氧云母复合绝缘
定子线棒
frequency domain dielectric spectrum
dielectric loss factor integral spectrum
epoxy mica composite insulation
stator bar
