摘要
为研究极寒条件下热老化油的介电性能和击穿特性,以45#变压器油为研究对象,在146℃下加速热老化15天,制备出不同老化程度(酸值分别为0.034、0.181、0.215 mgKOH/g)的变压器油,搭建低温测试平台,对不同老化程度的变压器油的介电性能和击穿特性进行测量和分析。结果表明:随着温度的降低,热老化油样的相对介电常数呈线性增加,电导率和介质损耗因数先增大后减小,在-10℃附近达到峰值;击穿电压整体上呈先减小后增大的趋势,在-10℃附近达到极小值。随着老化天数的增加,油中酸值不断增大,油样的相对介电常数、电导率和介质损耗因数都有所增加,且酸值越大,增加幅度越明显;老化程度较低的油样击穿电压与原样差别不大,而老化程度较高的油样(酸值为0.215 mgKOH/g)击穿电压比原样平均降低了39.9%,最大降幅在-10℃附近可达53.6%。
In order to study the dielectric properties and breakdown characteristics of thermal ageing oil under extremely low temperature,we take 45#transformer oil as research object,and transformer oils with different ageing degrees(acid values are 0.034,0.181,0.215 mgKOH/g)were prepared by accelerating thermal ageing at 146℃for 15 days.And a low temperature test platform was built.The dielectric properties and breakdown characteristics of transformer oil with different ageing degrees were measured and analyzed.The results show that the relative dielectric constant of heat ageing oil increases linearly with the decrease of temperature.The conductivity and dielectric loss factor increase at first and then decrease,reaching the peak value near-10℃.On the whole,the breakdown voltage decreases at first and then increases,reaching a minimum value near-10℃.With the increase of ageing days,the acid value of oil increases continuously,the relative dielectric constant,conductivity,and dielectric loss factor of oil increase,and the bigger the acid value,the more obvious the increase amplitude.The breakdown voltage of the oil with low ageing degree has little difference with the breakdown voltage of original sample,while the breakdown voltage of the oil sample with high ageing degree(acid value is 0.215 mgKOH/g)is 39.9%lower than that of the original sample on average,and the maximum drop can reach 53.6%near-10℃.
作者
周文豪
苏振鹏
唐飞然
刘晓峰
郑怀
张宇
李欢欢
ZHOU Wenhao;SU Zhenpeng;TANG Feiran;LIU Xiaofeng;ZHENG Huai;ZHANG Yu;LI Huanhuan(Wuhan University,Wuhan 430072,China;Guangzhou Power Supply Bureau of Guangdong Grid Co.,Ltd.,Guangzhou 510000,China)
出处
《绝缘材料》
CAS
北大核心
2022年第12期69-74,共6页
Insulating Materials
基金
南方电网公司科技项目(GZHKJXM20180141)。
关键词
极寒条件
热老化油
酸值
介电性能
击穿电压
extremely low temperature
heat ageing oil
acid value
dielectric properties
breakdown voltage
