The fault detection of transformer windings' deformation based on Vibration frequency response analysis

Abstract

Windings' deformation is one of the most common transformer faults. The paper proposes a new method of Vibration frequency response analysis (VFRA) in order to effectively detect the deformation. A series of experiments have been conducted on a large power transformer to validate its efficiency by testifying its repetitiveness and sensitivity. The first series of experiments used VFRA on phase A under the same status in different time. VFRA was used in the second series of experiments on phase C with purposely removing its insulation pressboard. The third used VFRA to test phase C with manmade radial deformation. All the first series of experimental results are nearly the same, which shows the good repetitiveness for this method. The second and third results with the artificial faults were compared with those in normal status, which shows that VFRA can effectively detect the windings' deformation. Compared with short-circuit reactance measurement, VFRA is more sensitive.