正极性电晕在空气中的起始判据

Onset Criterion for Positive Corona in Air

将电晕损耗和电晕效应控制在合理的水平是高压输电线路设计的一项关键内容,而电晕放电的起始条件对于电晕控制来说至关重要。为此,针对同轴电极结构,介绍了一种考虑光电离的常用正电晕起始判据的推导和简化过程,阐明了判据中各个参数的物理含义,并且给出了表征光子在圆柱导体电离层内吸收过程的面积因子及其展开式。比较了由正电晕起始判据及其简化形式得到的计算结果,同时与Peek的实验结果做了比较。在很大的导体半径范围内,该起始判据与其简化形式在相同条件下的差异非常小,并且该判据的计算结果与Peek的实验结果也都非常符合。

It is a key step for the design of the high voltage transmission line to control the corona loss and the corona effects under a reasonable level.The evaluation of the corona onset is especially important for the corona control.We present the derivation and the simplification of a widely used criterion for coaxial cylinders considering the photoemission,and clarify the physical significance of every parameter in the criterion.Moreover,a geometric factor and its expanded expressions characterizing the photo absorption in the ionization region of the cylindrical electrode are proposed.The results by the criterion and its simplified form under different conductor radii are compared and the difference between them is significantly small under the same conditions.The results by the criterion also well agree with Peek＇s experimental data for a wide range of conductor radii.