含金属微粒流动变压器油的直流局部放电与击穿特性研究  

DC partial discharge and breakdown characteristics of flowing transformer oil containing metal particles

作　　者：王金铜 温刚 姜东飞 黄志强 张玉辉 潘卓洪 WANG Jintong;WEN Gang;JIANG Dongfei;HUANG Zhiqiang;ZHANG Yuhui;PAN Zhuohong(Ultra High Voltage Branch of State Grid Xinjiang Electric Power Co.,Ltd.,Urumqi 830002,China;Hebei Key Laboratory of Power Transmission and Transformation Equipment Safety Defense,North China Electric Power University(Baoding),Baoding 071003,China)

机构地区：[1]国网新疆电力有限公司超高压分公司,新疆乌鲁木齐830002 [2]华北电力大学(保定)河北省输变电设备安全防御重点实验室,河北保定071003

出　　处：《绝缘材料》2023年第9期66-70,共5页Insulating Materials

基　　金：国网新疆电力有限公司科技项目(SGTYHT/21-JS-223)。

摘　　要：自由金属微粒通常被视为换流变压器液相绝缘中危害最大的污染杂质之一,可导致设备的局部放电(PD)起始电压与击穿电压显著降低。本文构建了变压器油循环系统,开展含金属微粒变压器油在不同油流速度下的直流局部放电与击穿试验,并提取PD特征量,获取了特征击穿电压随油流速度的变化,然后结合油隙的微粒分布影像,讨论油流速度对局部放电和击穿特性的影响机制。结果表明:油静止时,含金属微粒变压器油的局部放电程度最高,随着油流速度的增大,局部放电起始电压升高,放电重复率和单位时间累积放电量降低;油静止时,含金属微粒变压器油的击穿电压最低,随着油流速度的增大,击穿电压的Weibull分布曲线右移,特征击穿电压升高,即油流动提升了变压器油的绝缘性能,大幅降低了击穿发生的可能性。Free metal particles are usually regarded as one of the most hazardous contaminants in the liquid-phase insulation of converter transformers,which can lead to the partial discharge(PD)initial voltage and breakdown voltage of equipment decrease obviously.In this paper,a transformer oil circulation system was constructed,and DC partial discharge and breakdown experiments were conducted on the transformer oil containing metal particles at different oil flow velocity.The PD characteristic parameters were extracted,and the variation of characteristic breakdown voltage with oil flow velocity was obtained.Then the affecting mechanisms of oil flow velocity on the PD and breakdown characteristics were discussed combined with the particle distribution images between electrodes.The results show that when the oil is static,the partial discharge degree of the transformer oil containing metal particles is highest.With the increase of oil flow velocity,the PD initial voltage increases,and the discharge repetition rate and the accumulation discharge magnitude per unit time decrease.When the oil is static,the breakdown voltage of the transformer oil containing metal particles is lowest.With the increase of oil flow velocity,the Weibull distribution curve of breakdown voltage shifts to the right,and the characteristic breakdown voltage increases,that is,the flowing of oil improves the insulating properties of transformer oil and reduces the breakdown possibility remarkably.

关 键 词：金属微粒 直流 变压器油 局部放电 击穿特性 

分 类 号：TM214[一般工业技术—材料科学与工程]