Iron Core Modeling For Electrical Transients

A model for the magnetizing branch of the single phase transformer or iron core reactor is presented for the calculations of transients. Eddy currents in the core and saturation are taken into account. The finite dimensional model results from the numerical approximation of the nonlinear partial differential equations representi the diffusion of the electromagnetic field in the laminations of the core [1]1. Second order central difference formulae, trapezoidal integrtiona (with damping, if desired ( 2D, and Newton's method are used for the numerical solution. A Norton/Thevenin equivalent for the core is developed to permit using it as a component in a complete transformer or reactor model.