This paper presents the analytical solution of levitation problem for both magnetically anisotropic and conductive balls. The magnetic field exerts eddy currents in magnetic and conductive balls. The forces, both Lorentz (of eddy current) and material (caused by inhomogeneity of reluctivity), lead to the levitation of the ball. The electromagnetic field is determined by means of variable separation method. The forces, both Lorentz and material acting upon the ball, are calculated. Power losses are calculated twice by means of Joule volume integral and Poynting surface integral. The total force is evaluated three times by Maxwell, coenergy, and Lorentz methods. Levitation force and power losses versus frequency are presented. Asymptotic relations for levitation force and power losses are derived. The comparison to levitating disk at the same volume is presented.

This paper has dealt with two theoretical problems of electromagnetic force/torque calculation in anisotropic regions. The first problem considers equivalence of both Maxwell and Lorentz methods for magnetically anisotropic and conductive region. The second problem deals with the independence of force/torque value calculated by the Maxwell method from the integration surface position. It formulated the sufficient condition for this independence for anisotropic and nonconductive region.

The paper presents an approach to differential equation solutions for the stiff problem. The method of using the classic transformer model to study nonlinear steady states and to determine the current pulses appearing when the transformer is turned on is given. Moreover, the stiffness of nonlinear ordinary differential state equations has to be considered. This paper compares Runge–Kutta implicit methods for the solution of this stiff problem.

Deals with the problem of the electromagnetic torque calculation in the case of either nonuniformity of the air‐gap or eccentricity of the rotor. The electromagnetic field distributions have been evaluated for drag‐cup motors. An analytical model has been introduced for linear motor based on the variation method for magnetic flux density magnitudes. The total torque and its components have been evaluated for the motors chosen. The decrease of the electromagnetic torque and increase of eddy‐current losses have been discussed due to either rotor circular asymmetry or its eccentricity.