交直流叠加电压下针板模型放电及产气特性  

Discharge and Gas Characteristics of Needle-Plate Model Under AC-DC Combined Voltage

作　　者：龙方宇 张晓涵[2] 陈禾 魏振[2] 刘凡栋 张鹏[2] 杨栋 齐波[2] 

机构地区：[1]南方电网超高压输电公司检修试验中心,广州510663 [2]高电压与电磁兼容北京市重点实验室(华北电力大学),北京102206

出　　处：《南方电网技术》2015年第3期46-50,共5页Southern Power System Technology

摘　　要：换流变压器内电场以交直流叠加电场为主,与交流变压器有明显区别,因此其局部放电和产气特性与交流变压器不同,已有的交流诊断依据不适用于换流变压器,需要重新对判定依据进行总结。搭建了一套交直流复合电压作用下油纸绝缘针板放电试验平台,通过分析放电特征的时间变化趋势及统计规律,总结不同时间的产气特性,得到了适用于换流变压器的诊断依据。研究结果表明:交直流复合电压作用下放电和产气特性表现出明显的阶段特征,整个过程可以划分为3个阶段:放电起始阶段、发展阶段及临近击穿阶段;根据局部放电和产气特性的规律及趋势可以作为换流变压器针板放电阶段的判定依据,即脉冲重复率很小,烃类气体产出极少为起始阶段;脉冲重复率明显增加,CH4产出量大为发展阶段;绝对产气速率超过0.5 m L/h,C2H2产出量最大,且出现C2H6时为临近击穿阶段。The AC/DC superimposed electric field in converter transformer is quite different from AC transformer, resulting in differ-ent partial discharge and dissolved gases in oil. The existing diagnosis bases are not suitable for converter transformer, and need to be updated. A set of test platform for needle-plate model under AC and DC combined voltage is built to analyze the trend and statistical laws of discharge characteristics as well as to summarize the feature of dissolved gas in oil. The results show that the characteristics of discharge and dissolved gas in oil under AC/DC superimposed voltage interaction have distinct differences with 3 stages changing, namely, the inceptive stage, the developing stage and the imminent breakdown stage. The pattern and trend of partial discharge and dissolved gas in oil can be used as the diagnostic basis for converter transformer, wherein during the inceptive stage, the repetition of pulse is very small with very little hydrocarbon gas discharge, during the developing stage, the repetition of pulse increase dramatically with CH4 as the main portion of the hydrocarbon gas discharge, during the imminent breakdown stage, the absolute hydrocarbon gas discharge exceeds 0. 5mL/h with C2 H2 as the main portion, and C2 H6 will be detected at this stage.

关 键 词：换流变压器 故障 诊断依据 针板 局部放电 产气特性 

分 类 号：TM862[电气工程—高电压与绝缘技术]