首页|流动变压器油中金属微粒分布规律及其对击穿电压的影响机制

流动变压器油中金属微粒分布规律及其对击穿电压的影响机制

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作为对变压器液相绝缘危害最严重的污染杂质,金属微粒若在油间隙内部发生聚集,由于其强导电性,会大大缩短油隙的绝缘有效距离,甚至在外加电场的持续作用下引发绝缘击穿.为此构建了流动油中金属微粒分布与击穿特性测试平台,开展了交流电压下流动变压器油中金属微粒的分布规律与击穿特性试验,结合仿真,讨论了金属微粒分布特征对绝缘油击穿电压的影响机制,试验结果表明:一旦变压器油开始流动,微粒将难以在高场强区域聚集.随着电场场强的提升,微粒的聚集浓度增大.随着预压场强的增加,击穿电压的 Weibull 分布曲线均向左移动,其中位于低流速区的曲线偏移更为显著.仿真得到金属微粒在电极间的聚集情况,进一步分析了微粒在电极间的受力情况,理清了金属微粒聚集特性对击穿特性的影响机制.
Distribution Characteristics of Metallic Particles in Flowing Transformer Oil and Its Influence Mechanism on Breakdown Voltage
Metal particles,as the most detrimental contaminants to the liquid insulation of transformers,pose a significant threat when they accumulate within oil gaps.Due to their high conductivity,such accumulation drastically reduces the ef-fective insulation distance of the oil gap,potentially leading to insulation breakdown under the sustained application of an external electric field.We established a test platform for the distribution and breakdown characteristics of metal particles in flowing transformer oil.Experiments were conducted under AC voltage to investigate the distribution patterns and breakdown behavior of metal particles in flowing transformer oil.Combining experimental data with simulations,the mechanisms underlying the influence of metal particle distribution characteristics on the breakdown voltage of insulating oil were discussed.The results indicate that,once the transformer oil begins to flow,particles become less likely to accu-mulate in high-field-strength regions.As the electric field strength increases,so does the concentration of particle accumulation.Moreover,the Weibull distribution curves of breakdown voltage shift leftward with the rise of the pre-stressing field intensity,with more pronounced shifts observed in the low flow velocity region.Simulations reveal the aggregation of metal particles between electrodes,the forces acting on these particles are further analyzed,and the mecha-nisms by which metal particle aggregation characteristics impact breakdown characteristics are clarified.

flowing transformer oilAC voltagemetal particlesaccumulation characteristicsbreakdown characteristic

高晨洋、潘成、姚雨杭、于梦悦、唐炬

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武汉大学电气与自动化学院,武汉 430072

流动变压器油 交流电压 金属微粒 聚集特性 击穿特性

国家电网公司科技项目

52053023001T

2024

高电压技术
中国电力科学研究院 中国电机工程学会

高电压技术

CSTPCD北大核心
影响因子:2.32
ISSN:1003-6520
年,卷(期):2024.50(10)