Ladder‐Wise calculation method for <i>z</i>‐coordinate of transformer PD source based on planar layout UHF antenna sensors

Abstract

In locating a transformer partial discharge (PD) source, there is a large fluctuation error in the z ‐coordinate of the location, which results with planar layout ultrahigh‐frequency (UHF) antenna sensors. For the large fluctuation error, this paper first theoretically analyzes the reason. According to the theoretical analysis results, a ladder‐wise calculation method of the PD source z ‐coordinate is proposed: first, the x ‐ and y ‐coordinates of the PD source are calculated, then the univariate equation f ( z ) is derived, and the z ‐coordinate of the PD source is obtained by f ( z ). Finally, the positioning effect of the ladder‐wise calculation method for PD source z ‐coordinate is verified experimentally. Experimental results show that the proposed method can reduce the fluctuation of the z ‐coordinate of the PD source from 0.6 to 0.2, and when the PD location sample set is ≥10, the average absolute error of the z ‐coordinate is reduced from about 0.4 m to less than 0.1 m. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley &amp; Sons, Inc.