Characterization of transformer harmonic behavior using finite element analysis and discrete wavelet transforms

This paper investigates the harmonic behavior of three phase power transformer under non linear load condition. The terminal behavior of the transformer was obtained by coupling the transformer transient FE model and external electric circuits. Such a technique would allow the physical representation of the nonlinear magnetization behavior of the transformer as well as the strong frequency dependence of the transformer parameters. The harmonic behavior of the transformer currents and the dc load current were analyzed using discrete wavelet transform (DWT). The results of applying the DWT are discussed.