Simulation of a three-phase transformer using an improved anisotropy model

The nonlinear and anisotropic behavior of grain-oriented ferromagnetic materials enters numerical field computations via the reluctivity tensor. In this paper, an improved reluctivity tensor model is discussed. It is pointed out in which way this model is integrated in a Newton iterative solver. However, to retain the attractive properties of the conjugate gradient algorithm, it is required to modify the definition of the Jacobian matrix. Several simulations of a three-phase transformer are performed and compared, in order to demonstrate the properties of the reluctivity model and the proposed Newton solver.