TY - JOUR N2 - This paper presents a methodology for the calculation of the flux distribution in power transformer cores considering nonlinear material, with reduced computational effort. The calculation is based on a weak coupled multi-harmonic approach. The methodology can be applied to 2D and 3D Finite Element models. The decrease of the computational effort for the proposed approach is >90% compared to a time-stepping method at comparable accuracy. Furthermore, the approach offers a possibility for parallelisation to reduce the overall simulation time. The speed up of the parallelised simulations is nearly linear. The methodology is applied to a single-phase and a three-phase power transformer. Exemplary, the flux distribution for a capacitive load case is determined and the differences in the flux distribution obtained by a 2D and 3D FE model are pointed out. Deviations are significant, due to the fact, that the 2D FE model underestimates the stray fluxes. It is shown, that a 3D FE model of the transformer is required, if the nonlinearity of the core material has to be taken into account. L1 - http://www.czasopisma.pan.pl/Content/85058/PDF/11_paper.pdf L2 - http://www.czasopisma.pan.pl/Content/85058 PY - 2015 IS - No 1 March EP - 138 DO - 10.1515/aee-2015-0012 KW - flux distribution KW - local flux variations KW - multi-harmonic FEM KW - nonlinear FEM KW - power transformer A1 - Riemer, Björn A1 - Hameyer, Kay PB - Polish Academy of Sciences VL - vol. 64 DA - 2015[2015.01.01 AD - 2015.12.31 AD] T1 - Multi-harmonic approach to determine load dependent local flux variations in power transformer cores SP - 129 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/85058 T2 - Archives of Electrical Engineering ER -