Hamid Radmanesh - Department of Electrical Engineering, Amirkabir University of Technology (Tehran Polytechnic
Hamid Fathi
Seyed Usef Mosazade
Hossein Hosseinian

This paper studies the effect of iron core saturation characteristic degree on the occurrence of harmonic modes in an autotransformer. The selected transformer for study has arating of 50 MVA, 635.1 kV. The magnetization characteristic index of the autotransformer is chosen with q=5, 7, 11. Thelinear core loss is considered for transformer core. The MATLAB software is used for analyzing existence harmonic modes in the proposed power system. It is shown high orderharmonics are occurred when degree of core nonlinearity is gone from 5 to 11.

Linear core losses, Autotransformers, harmonic modes, nonlinear core degree