Diagnostics of power transformer using 3D FEM and SFRA measurements

Summary

This paper deals with options of power transformer diagnostic. The paper describes pros and cons of various commonly used diagnostic options approaches. Further, a novel approach of power transformers diagnostics is proposed and described in this paper. This approach identifies the exact location and the range of a fault in the transformer and helps to reduce operation costs related to handling of the faulty transformer, its disassembly and repair, which is very expensive in practise. The advantage of the approach is a possibility to simulate healthy transformer and also all faults, which can occur in transformer during its operation without its disassembling, which is very expensive in practice. The approach is based on creating frequency dependent impedance of the transformer by sweep frequency response analysis measurements and by 3D finite element (FE) parametric modeling of the fault in the transformer. The parameters of the 3D FE model are the position and the range of the axial short circuit. Then, by comparing the frequency dependent impedances of the parametric models with the measured ones, the location and the range of the fault is identified. The approach was tested on a real transformer and showed high coincidence between the real fault and the simulated one.

Additional informations

Authors

Yoshida Takashi, Shimizu Yoshinori, Torii Hirotaka