不同因素影响下的油纸绝缘直流击穿特征

DC Breakdown Characteristics of Oil-paper Insulation Under Influence of Different Factors

由于系统性原因,换流变压器阀侧在实际运行过程中长期承受直流电场分量作用,油纸绝缘在直流电压下的耐受能力是换流变压器设计过程中的重要关注点。文中考虑谐波含量、油温、含气量、油纸介电常数、纸板浸渍程度等各种潜在因素,开展了油纸绝缘直流击穿特征的基础试验研究,并用初始电子发射、空间电荷、杂质小桥等电介质理论对结果予以合理阐释,相关结论可对换流变压器阀侧绝缘结构优化和场强设计提供一定的参考。

For certain systematic reasons,the valve side of converter transformer bears DC electric field component over a long time in the actual operation process.The tolerance of oil-paper insulation under DC voltage is an important concern in the design process of converter transformer.Considering various potential factors such as harmonic content,oil temperature,gas content,oil-paper dielectric constant,paper impregnating degree and oil-gap spacing,the basic experimental study on DC breakdown characteristics of oil-paper insulation is carried out,and the dielectric theories such as initial electron emission,space charge and impurity bridge are used to explain the results reasonably.Relevant conclusions can provide some references to the valve side insulation structure optimization and field strength design of the converter transformer.