基于测向线公垂线中点的局部放电相控超声几何定位算法研究

Research on Algorithm for Ultrasonic Array Geometric Location of PD Based on Common Perpendicular Midpoint of Direction Finding Lines

局部放电的定位检测是电气设备质量监控与状态检修的关键项目,良好的阵列定位原理及算法是保证定位精度的前提条件。传统局放超声阵列定位算法将所得的两条测向线投影交点的法线与两条测向线的交点视为放电源,这种近似处理方法原理简单、计算方便。但是,由于超声信号在变压器中的折反射和各类测向误差的影响,两条测向线是不可能交汇于局放源这一点,因此实际两条测向线为异面直线,近似处理为相交,会导致由于测向不准带来的定位精度下降,而且会出现多个不唯一解的情况,无法满足工程实际需要。因此笔者提出了一种基于测向线公垂线中点的局部放电相控超声几何定位算法,该方法将两条测向线公垂线的中点作为局放源位置,使得局放定位结果唯一、稳定,同时也提高了定位精度。实验结果验证了文中方法的正确性和优越性。

Detection of partial discharge（PD） location is the crucial project of electrical equipment＇s quality monitoring and transformer＇s condition maintenance, good array location principle and the algorithm are the precondition for the guarantee of the location accuracy research. It regards the point of the intersection of two direction measuring lines and their projection as PD source in traditional algorithm for ultrasonic array location of PD. The theory of this method is simple and the calculation is not complicated. However, as the influences of ultrasonic signal＇s refraction and reflection, and of variety of measurement errors, the two direction measuring lines are in different planes, approximately treated as the intersection, a lot of problems may be caused, such as bringing down the positioning accuracy. Furthermore, this could not get the unique solution which could not meet the actual engineering needs. Based on the midpoint of perpendicular public of direction measuring lines, in this paper, the author presents a new algorithm for ultrasonic array geometric location of PD. This method regards the public perpendicular midpoint of direction measuring lines as the location of PD source which could obtain the unique solution of the location result and improve the positioning accuracy. The experimental results verify the correctness and superiority of this proposed method.