Harmonic domain modeling of laminated iron core

The steady-state modeling of a laminated saturating iron core is discussed. The modeling is in the harmonic domain, i.e. in terms of phasors for the different harmonics due to the nonlinear magnetization characteristic. The procedure is based on a polynomial approximation of the magnetization characteristic. In the harmonic domain the computations can then be performed by simply replacing time-domain multiplications by convolutions. The lamination is discretized, and Maxwell´s equations are written in terms of discrete local field quantities, B, H, and E. The end result is a matrix equation solved by linearization, which it yields harmonic-domain components of B and H over the cross-section of the lamination. The method can be used in practical problems, such as ferroresonance, for obtaining more accurate results than with presently available simple procedures.