基于声学性能的发电机定子线棒主绝缘热老化特性研究  

Research on thermal ageing characteristics of main insulation for generator stator bar based on acoustic performance

作　　者：刘向东 李青 聂靓靓 杨航 黄明浩 凌鹏 王韦玉 金海云[2] LIU Xiangdong;LI Qing;NIE Liangliang;YANG Hang;HUANG Minghao;LING Peng;WANG Weiyu;JIN Haiyun(Maintenance and Test Company,CSG Power Generation Co.,Ltd.,Guangzhou 511400,China;State Key Laboratory of Electrical Insulation and Power Equipment,Xi′an Jiaotong University,Xi′an 710049,China;State Grid Zhejiang Electric Power Company Hangzhou Power Supply Company,Hangzhou 310000,China)

机构地区：[1]南方电网调峰调频发电有限公司检修试验分公司,广东广州511400 [2]西安交通大学电力设备电气绝缘国家重点实验室,陕西西安710049 [3]国网浙江省电力有限公司杭州供电公司,浙江杭州310000

出　　处：《绝缘材料》2023年第9期60-65,共6页Insulating Materials

基　　金：中国南方电网有限责任公司调峰调频发电公司科技项目(022200KK52190007)。

摘　　要：基于超声波测试原理,以发电机VPI定子线棒为研究目标,设计加速热老化试验,对各老化温度下试样的超声声速、超声频谱、超声缺陷波形图等进行分析,同时在绝缘试样中引入人为孔洞缺陷和杂质缺陷,探讨缺陷的引入对试样超声波形的影响。结果表明:随着热老化试验的进行,定子线棒主绝缘中的超声声速整体呈下降趋势,其原因是定子线棒主绝缘试样在热老化过程中,内部结构的分层会导致声波传播过程出现折反射与耗散,造成声波在绝缘试样内部传播速度变小。通过超声回波可以检测到缺陷并对其进行准确定位,表明声学性能检验法在定子线棒主绝缘诊断方面具有较好的适用性。An accelerated thermal ageing test was designed for the main insulation sample of a generator VPI stator bar,and the ultrasonic velocity,ultrasonic spectrum,and ultrasonic defect waveform of samples were analyzed at various ageing temperatures on the basis of the principle of ultrasonic testing.At the same time,artificial hole defects and impurity defects were introduced into the insulation samples to explore the effect of defect introduction on the ultrasonic waveform of the samples.The results show that as the thermal ageing test progresses,the overall ultrasonic velocity in the main insulation of stator bar shows a decreasing trend.The reason is that during the thermal ageing process of the stator bar main insulation sample,the layering of internal structure can cause refraction,reflection,and dissipation of the sound wave during propagation process,resulting in the propagation speed of the sound wave in the insulation sample decrease.The defects can be detected and accurately located through ultrasonic echoes,which indicates that the acoustic performance testing method has good practicality in the diagnosis of stator bar main insulation.

关 键 词：绝缘老化 超声声速 超声频谱 超声缺陷波形 

分 类 号：TM303.4[电气工程—电机]