重复脉冲电压下变频牵引电机绕组绝缘的电树枝特性  

Electrical Tree Characteristics in Winding Insulation for Inverter-fed Traction Motor Under Repetitive Impulse Voltages

作　　者：唐艳霞 刘学忠[1] 王景娜 郭玉柱 刘嬿 李丹 TANG Yanxia;LIU Xuezhong;WANG Jingna;GUO Yuzhu;LIU Yan;LI Dan(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China;Guangzhou Power Supply Company,Guangdong Power Grid Corporation,Guangzhou 510620,China;CRRC Yongji Electric Co.,Ltd.,Xi’an 710016,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [2]广东电网有限责任公司广州供电局,广州510620 [3]中车永济电机有限公司,西安710016

出　　处：《高电压技术》2023年第6期2625-2633,共9页High Voltage Engineering

摘　　要：变频牵引电机在快速发展的轨道交通运输中起重要作用,其在运行时需要承受高频脉冲电压的冲击,且绕组的绝缘温升较高,需采用高耐热性绝缘浸渍漆和绝缘带构成的复合绝缘系统。为此选用了两种常用的C级耐热浸渍漆,配合3种绝缘带构成层状复合绝缘电树枝试样,在不同重复率的双极性方波脉冲电压下,试验实时观测了电树枝的引发、形态特征和生长过程,对比研究了不同层状复合绝缘的电树枝化特征和破坏机理。试验对比和研究分析表明:电树枝在聚丁二烯树脂浸渍漆中的引发时间较长,径向生长速率明显更快,而有机硅树脂浸渍漆中的电树枝更容易引发,但引发后生长速度较慢;随脉冲电压重复率提高,电树枝更易引发,径向生长速率更快,但两种浸渍漆中电树枝的形态变化不同;3种绝缘带对电树枝的生长都具有显著的界面阻碍作用,且玻璃布补强云母带与聚酰亚胺薄膜和聚酰亚胺薄膜补强云母带相比,对电树枝生长的抑制效果最突出,更适用于高频脉冲电压作用下的变频电机或高频变压器绝缘系统。The inverter-fed traction motor plays an important role in the rapidly developing railway transportation,and needs to withstand the impact of high-frequency pulse voltage;moreover,its temperature rise of winding insulation during operation is high,which requires a composite insulation system composed of high heat-resistant insulating impregnating varnish and insulating tape.In this paper,two commonly used impregnating varnishes with the thermal class of C are selected,and three kinds of insulating tapes are composed to prepare different layered composite insulation samples of electrical tree.In order to study the electrical tree characteristics and failure mechanism in different composite insulations,the initiation and morphological characteristics and growth process of electrical tree under the bipolar square wave impulse voltage with different repetitive rates were experimentally investigated and observed with a real-time microscope digital imaging system.By comparison of experiments and research analysis,it is shown that the initiation time of electrical trees in polybutadiene impregnating varnish is much longer than that of the silicone impregnating varnish,and the radial growth rate is significantly faster.The electrical trees in silicone impregnating varnish are more easy to initiate,however,their growth rates after the initiation are slower.With the increase of the impulse voltage repetitive rate,the electrical trees are more easy to initiate and the radial growth rate is faster,whereas,the morphological changes of the electrical trees in two impregnating varnishes are different.The three kinds of insulating tapes have excellent interfacial hindering effect on the growth of electrical trees.Among them,the glass cloth reinforced mica tape,compared with the polyimide film and polyimide film reinforced mica tape,has the most prominent inhibitory effect on the growth of electrical tree,so it is more suitable to be used for the insulation system of the inverter-fed traction motor or high-frequency transformer,w

关 键 词：电树枝 变频牵引电机 重复脉冲电压 聚丁二烯树脂 有机硅树脂 

分 类 号：U264[机械工程—车辆工程]