基于改进三平台测向原理的变压器局放超声定位研究

Ultrasonic Location of Partial Discharge in Transformer Based on Improved Three-platform Direction Finding Principle

由局放定位原理分析得出方位角和俯仰角误差会导致定位误差随着局放源与测向平台之间距离的增加而被放大,而局放源与测向平台之间的距离可根据实验室模拟变压器局放实验求得的超声信号峰值的平均值随局放源与测向平台之间距离的变化曲线求得,在此基础上提出一种基于改进三平台测向原理的变压器局放超声定位方法。利用3条测向线可以确定3个辅助定位点(即由误差放大原理在两两测向线公垂线上求得,其到测向线的距离与局放源到测向平台之间的距离成正比),根据统计学中取平均值可以在最大程度上减小随机误差对测量结果影响的原理,取3个辅助定位点确定的平面圆的圆心为局放源的位置。实验结果证实了文中所提方法可以提高局放源的定位成功率和精度,具有较大的实际应用价值。

An ultrasonic location method of partial discharge（PD）in transformer based on the improved threeplatform direction-finding principle is proposed. The method takes it into consideration that azimuth and elevation error will enlarge positioning error with the increase of the distance between PD source and platform. The distance between the auxiliary anchor point and the direction finding line is proportional to the average of the maximum peaks of received signals. The average of the maximum peaks of received signals from different sensors in same array is measured through laboratory simulation experiment, and the experiment needs to be conducted for several times if the distance between PD source and platform is different. When the average of the maximum peaks is obtained, the distance between PD source and platform can be easily achieved on the basis of the relationship curve. Considering that the position of auxiliary anchor point is on the common perpendicular and the distance between auxiliary anchor point and direction finding line is proportional to the average of the maximum peaks, a plane circle can be determined by three auxiliary anchor points following the three-platform direction-finding principle, and the center of the circle is taken as the position of PD source. Experiment verifies that the proposed method can improve the location success rate and accuracy of transformer PD position.