球–球电极下变压器油冲击放电的尺寸效应  

Scale Effect of Impulse Breakdown in Transformer Oil with Sphere-sphere Electrodes

作　　者：袁炜雄 张乔根[1] 王同磊 倪鹤立 高萌[1] 丁玉琴[1] YUAN Weixiong;ZHANG Qiaogen;WANG Tonglei;NI Heli;GAO Meng;DING Yuqin(School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710049,China)

机构地区：[1]西安交通大学电气工程学院

出　　处：《高电压技术》2018年第12期3958-3965,共8页High Voltage Engineering

摘　　要：油浸式电力设备的冲击绝缘强度与结构尺寸有关。为得到尺寸效应对变压器油冲击放电的影响,实验研究了陡前沿冲击电压下球–球电极油间隙随电极面积、间隙距离的放电特性,并利用统计学方法对实验数据进行了分析。总结实验结果,给出了变压器油平均击穿场强关于电极面积A、间隙距离d的经验公式,同时得到三参数Weibull分布形状参数与电极直径、间隙距离之间的关系。通过计算有效作用面积Aeff并与实际放电蚀坑面积对比,结果表明利用三参数Weibull分布形状参数计算得到的有效作用面积与实际情况更为符合。最终建立了三参数Weibull分布形状参数m与电场利用系数η的关系,进而获得了电极尺寸与有效作用面积的关系,为其绝缘设计提供重要参考。The impulse breakdown electric strength of oil-immersed power equipment is related to the physical dimension significantly. In order to study the size effect in transformer oil under steep front voltage, we studied the electrical breakdown characteristics of transformer oil under different electrode area and inter-electrode distance in the sphere-sphere electrodes using a statistical method. The empirical formulas of the dependence of the average electric strength on different stressed electrode areas and interelectrode distances were obtained according to experimental results. The relationships between the shape parameter m and electrode diameter as well as interelectrode distance were also acquired. By comparison of the calculated Aeff and the pit area, it is shown that the Aeff obtained by using 3-parameter Weibull distribution’s shape parameter m is tally with the actual situation. The field utilization factor η as a function of shape parameter m has been calculated so that the relationship of electrode physical dimension and stressed area is established, which can be used for its insulation design.

关 键 词：变压器油 冲击放电 Weibull分布函数 尺寸效应 稍不均匀场 绝缘设计 

分 类 号：TM855[电气工程—高电压与绝缘技术]