Extracting Indices to Detect Mechanical Fault Extent in Transformers: A Probabilistic Approach

The evaluation of frequency response curves is an important problem in transfer function (TF) method to diagnose mechanical faults of transformer winding. Several numerical indices have been proposed by researchers to interpret TF of power transformers, but the researchers have not discussed on the origin of the selected indices. In this paper, a probabilistic approach has been used to show how an efficient numerical index originates, to detect axial displacement (AD) in windings of power transformers. The resulted group of indices presents a nearly linear mapping between frequency response curves and their related defect extent. To verify usefulness of this group of indices, it has been applied to some measured frequency response curves. It is illustrated that the extracted indices is able to determine the extent of the AD in transformer winding.

کلیدواژه ها:

Power transformer ، Transfer function (TF) ، Probabilistic reasoning ، Axial displacement ، Distance function