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The variations in the longitudinal drag force on a magnet close to a slowly moving strip sample of electrical steel have provided sensitive, nondestructive indications of local inhomogeneity in the permeability, dimensions and hysteresis loss of the sample. The measurements of both grain-oriented and nonoriented electrical steels have shown drag force variations of unexpectedly large amplitude for movements of just a few millimeters.

The optimal geometry of a passive shield for the reduction of the magnetic stray field of an axisymmetric induction heater is found. The currents in the shield are found by solving an electrical circuit and space mapping combines both models to obtain the optimal passive shield fast and accurately.

An optimization of a multilayered material is presented for the shielding of sinusoidal magnetic fields. The results show that both the optimal shield thickness and the fraction of steel decrease with the frequency.

A method is developed to calculate the core loss in a switched reluctance machine and the magnetic circuit of the motor is described as a magnetic network. Using the numerical routines, the local core loss in the different motor sections is calculated and the global core loss is compared with the experimentally determined core loss.

Analytical expressions are presented to find the shielding effectiveness and the losses of a shield consisting of ferromagnetic, isotropic, nonlinear, and hysteretic material, characterize by the Preisach distribution function in the Rayleigh region. The nonlinear shield is divided into a sufficient number of piecewise linear sublayers with a permeability that is constant and complex.