Diagnostics of a Transformer's Active Part With Complementary FRA and VM Measurements

This paper presents the concept of complementary measurements with the use of two methods that allow for a more detailed assessment of the mechanical condition of a transformer's active part. These methods are frequency-response analysis (FRA) and vibroacoustic method (VM). The VM was interpreted separately in steady and transient conditions, thus allowing, together with the FRA measurements, the determination of possible source of vibrations. This paper presents a theoretical introduction, experimental measurements performed on a real transformer with introduced controlled deformations and, finally, an example of a practical application.