Mat-1.3656 Seminar on numerical analysis and computational science

Monday, Oct 3, 2011, room U322 at 14.15, Eirola & Stenberg

Paavo Rasilo, A"
Modeling of iron losses in electrical machines by FEM

Electrical machines are commonly analyzed with the 2-D finite element method (FEM) by solving Ampere's law in the cross-sectional domain in terms of the magnetic vector potential. In the iron core of the machine, ferromagnetic hysteresis causes the material properties to be history-dependent which makes it difficult to find the solution using the Newton-Raphson method. In addition, the eddy currents induced into the core are typically 3-D in nature and thus difficult to be modeled in the 2-D domain. Due to these difficulties, the hysteresis and eddy-current effects have usually been omitted from the FE solution. In this presentation, some methods of modelling these phenomena within the 2-D FEM are described.