热应力与电-热复合应力下油纸绝缘老化特性的比较研究(英文)  

Comparative Research of Oil-paper Aging Characteristics Under Thermal Stress and Combined Thermo-electrical Stresses

作　　者：王世强 吴凤娇 许昊 张冠军 

机构地区：[1]State Key Lab of Electrical Insulation and Power Equipment,Xi'an Jiaotong University

出　　处：《高电压技术》2011年第11期2807-2813,共7页High Voltage Engineering

基　　金：Supported by National High Technology Research and Development Program of China(2007AA04Z411);National Basic Research Program of China(2009CB724505-1);Open Fund of State Key Laboratory of Power Transmission Equipment & System Security and New Technology(2007DA10512709405)

摘　　要：During the operation of power transformer,its oil-paper insulation is continuously subjected to various stresses,c.g.,the thermal,electrical,mechanical,and chemical stresses,which cause insulation aging gradually.It has been considered that the combined thermal and electrical stresses are the most important and unavoidable factors that induce insulation materials aging.In this work,accelerated aging experiments of oil-impregnated pressboards under combined thermal(130℃) and electrical stresses(4 kV/mm) are performed,while the aging experiments under single thermal stress are also carried out at the corresponding temperature(130℃).The electrical and physic-chemical properties of oil,including dielectric losses factor tanδ,resistivity,acid value and pH value etc.,are measured during the aging process.Dissolved gasses in oil and polymerization degree of cellulose are also measured.The relationship between these properties of oil-paper insulation and aging time is investigated.The results show that dissolved gases in oil,resistivity,tanδof oil under combined thermal and electrical stresses are obviously different from that tinder thermal stress during aging process while some other properties show similar changing trend.For cellulose, compared with the single thermal aging results,it even shows a slower degradation rate in the presence of electrical stress.During the operation of power transformer, its oil-paper insulation is continuously subjected to various stresses, e. g. , the thermal, electrical, mechanical, and chemical stresses, which cause insulation aging gradually. It has been considered that the combined thermal and electrical stresses are the most important and unavoidable factors that induce insulation materials aging. In this work, accelerated aging experiments of oil-impregnated pressboards un der combined thermal （130℃） and electrical stresses （4 kV/mm） are performed, while the aging experiments under single thermal stress are also carried out at the corresponding temperature （130 ℃）. The electrical and physic-chemical properties of oil, including dielectric losses factor tanδ resistivity, acid value and pH value etc. , are measured during the aging process. Dissolved gasses in oil and polymerization degree of cellulose are also measured. The relationship between these properties of oil-paper insulation and aging time is investigated. The results show that dissolved gases in oil, resistivity, tanδ of oil under combined thermal and electrical stresses are obviously different from that under thermal stress during aging process while some other properties show similar changing ：trend. For cellulose, compared with the single thermal aging results, it even shows a slower degradation rate in the presence of elec trical stress.

关 键 词：AGING combined thermal and electrical stresses dissolved gas polymerization degree oil paper insulation oil impregnated pressboard TRANSFORMER 

分 类 号：TM855[电气工程—高电压与绝缘技术]