局部放电作用下变压器匝间油纸绝缘加速劣化规律  

Development Rules of Accelerated Degradation of Oil-Paper Insulation between Turns in Transformer Windings Induced by Partial Discharge

作　　者：程养春[1] 魏金清[1] 李成榕[2] 荣智海[1] 王广真 马振丽[1] 

机构地区：[1]华北电力大学高电压与电磁兼容北京市重点实验室,北京102206 [2]华北电力大学新能源电力系统国家重点实验室,北京102206

出　　处：《电工技术学报》2015年第18期203-212,共10页Transactions of China Electrotechnical Society

基　　金：国家重点基础研究发展计划(973计划)(2009CB724508)资助项目

摘　　要：为研究变压器内油纸绝缘材料局部放电作用下劣化缺陷的发展规律及其与局部放电特征量的关联性,构建了匝间局部放电模型,进行了多组不同加压时间长度的恒压试验,并记录了试验过程中的局部放电信号。利用匝间绝缘纸带可层层拆解的结构特点,获得了匝间绝缘在加速电劣化下炭化通道发展的统计性规律。研究结果表明,恒压加速电劣化作用下匝间油纸绝缘局部放电缺陷即炭化通道沿宏观电场的纵向发展过程呈现增长、停滞和击穿三个基本阶段;脉冲重复率和脉冲1s内总放电量可以宏观地表征匝间油纸绝缘电劣化缺陷的发展状况,为油纸绝缘局部放电严重程度阶段性的准确划分提供参考依据。Tests based on the inter-turn partial discharge model are conducted to study the development rules of oil-paper insulation material defects generated by partial discharge in power transformers and its possible correlation with the characteristics of partial discharge. The constant voltage is adopted in this series of tests. High voltage is applied on the inter-turn electrode specimens with different time length in different groups of tests. Real-time detection is conducted to record conventional impulse current signals from partial discharge. After tests, insulation tapes were stripped from inter-turn electrodes lay by layer. In this way, the statistical laws about the development rules of the carbon channels generated by accelerated degradation between turns are acquired. The results show that the development of the carbon channels generated by accelerated degradation under a high constant voltage can be divided into three basic stages： growth, stagnation, and breakdown. The pulse repetition rate and the summation of pulse amplitude per second can reflect the insulate degradation development state of the inter-turn oil paper system. Based on these results, the severity of partial discharge in the oil-paper insulation can be assessed accurately.

关 键 词：变压器 油纸绝缘 局部放电 加速电劣化 炭化通道 发展规律 

分 类 号：TM835[电气工程—高电压与绝缘技术]