高寒条件下变压器油击穿特性试验  

Experimental Research on Breakdown Characteristics of Transformer Oil at Extremely-low Temperature

作　　者：徐征宇[1] 程涣超[1] 汪可[1] 遇心如 赵晓宇[1] 李光范[1] 

机构地区：[1]中国电力科学研究院,北京100192

出　　处：《高电压技术》2015年第4期1342-1348,共7页High Voltage Engineering

基　　金：国家电网公司科技项目(GY71-12-027)~~

摘　　要：对变压器油在低温环境下击穿特性的研究有助于确保高寒地区变压器的运行可靠性。为此建立了高压低温试验系统,利用该系统试验研究了在-50-10℃温度范围内,不同电压形式、电极模型、水分体积分数下的油隙击穿特性;并根据试验结果给出了高寒条件下对变压器投运及交接试验的建议。结果表明：交流电压和直流电压下,油隙击穿电压随温度的变化曲线呈U形,冲击电压下则无明显规律;平板电极模型、球–板电极模型和针–板电极模型击穿电压随温度的变化曲线均呈U形,且击穿电压值受电极间电场均匀程度的影响;低温下水分体积分数会对油隙的低温击穿电压产生直接影响,且在-10-0℃范围内影响最为显著。To analyze the breakdown characteristics of transformer oil under extremely-low temperatures so as to ensure the reliability of transformer operation in cold regions, we established a high voltage experimental system which could simulate extremely-low temperatures. On the basis of this system, we tested the breakdown characteristics of oil gap with various voltage waveforms, electrode models, or volume fractions within-50-10℃, and proposed suggestions on transformer energizing and test commissioning under extremely-low temperatures according to the results. It is obtained that, under AC/DC voltages, the waveform of breakdown voltage of oil gap vs temperature is U-shaped, but shows little tendency under impulse voltages. This waveform keeps U-shaped under several electrode models, including plate-to-plate, sphere-to-plate, and needle-to-plate models, and the breakdown voltage is determined by uniformity of the electrical field between the electrodes. At a low temperature, especially in the range of-10-0 ℃,the breakdown voltage is greatly affected by the volume fraction of water in transformer. The results can be used as references for securing transforms to operate safely in cold regions.

关 键 词：高寒 油隙 击穿 电压形式 电极模型 水分体积分数 

分 类 号：TM855[电气工程—高电压与绝缘技术]