高压直流导线表面粗糙度与电晕放电时粗糙系数的关系

Relationship Between the HVDC Conductor Surface Roughness and the Roughness Coefficient of Corona Discharge

高压输电线路表面磨损会对线路电晕放电造成影响。粗糙系数是根据导线表面状态预测起晕场强的重要参数。文中研究了表面粗糙度与高压直流导线起晕场强以及粗糙系数之间的关系,基于触针法测量了圆截面导线的表面粗糙度,利用圆柱电晕笼获得了导线正负极直流起晕电压,得到了粗糙系数与导线表面粗糙度之间的变化规律。导线粗糙度在0.5μm到2.5μm的范围内变化时,粗糙系数随表面粗糙度增大而减小。与正极相比,表面粗糙度对负极电晕放电影响更大。表面粗糙度越大,粗糙度变化对粗糙系数的影响越明显。

The surface wear of high voltage transmission lines will influence the corona discharge characteristics.The roughness coefficient is an important parameter to predict the corona initial electric field according to the surface condition of conductors.In this paper,the relationship between the conductor surface roughness and the DC corona initial electric field or the roughness coefficient is researched.The surface roughness of conductors with circular cross-section is measured with contact stylus method.Positive and negative corona initial voltages of conductors are analyzed by using a cylindrical corona cage.The functional relation between surface roughness and roughness coefficient is presented.It is revealed that the roughness coefficient decreases with the increase of the surface roughness from 0.5μm to 2.5μm.Compared with positive corona discharge,the surface roughness has a stronger effect on negative corona discharge.The influence of surface roughness on roughness coefficient is more significant with the surface roughness becoming larger.