Study on localization of transformer partial discharge source with planar arrangement UHF sensors based on singular value elimination

The large-scale power transformer gap leakage electromagnetic wave partial discharge detection method belongs to the external UHF detection method. This method can perform partial discharge insulation detection on the large-scale power transformer that is running without any modification of the power transformer, and the principle is simple and convenient to use. We have studied the reliability and the leakage electromagnetic wave propagation characteristics. However, this method requires UHF sensors in the same gap plane. When performing PD localization, it has the shortcomings of large positioning error and easy deviation of positioning results due to on-site noise pollution. For this problem, this paper proposes a PD source localization method based on singular value elimination. This method maps the three-dimensional coordinate sample set of the PD source to one-dimensional coordinates, and uses the improved box-plot diagram method to eliminate the singular values. Then the least square method is used to find the optimal coordinate of the real PD source. The proposed method has the advantages of greatly improving the data utilization efficiency of the PD sample set and effectively eliminating the singular values. Finally, the experimental verification of the proposed new method is carried out. The experimental results show that the proposed localization method can effectively improve the localization accuracy of PD source.