Modelling of winding failures identification using the frequency response analysis (FRA) method

The frequency response analysis method of investigation of windings is one of the methods being introduced more and more, recently. It is being used for the identification of dislocations and deformations of transformer windings as well as for the early detection of winding failures in electrical machines. This method is based on the comparison of the transfer function with reference measurements. The application of this method in the investigation of windings is determined by a measurement of the transfer function and by mathematical modelling. Both methods of determining the transfer function of the windings are being refined and developed. The numerical simulations are aiming at determining the sensitivity of this method and developing the recognition criteria with regard to the type and range of the deformations. This paper presents a numerical simulation method of the frequency dependences of transfer function of windings. The calculation results of the transfer function performed on the different winding of transformers and electrical machine are presented. Theoretical results are compared to the experimental ones. (C) 2009 Elsevier B.V. All rights reserved.