Modulated wave characteristics of two-phase magnetic levitation induction linear motor

We discuss the shifting magnetic field generated by a two-phase modulated wave composed of a basic wave of 60 Hz and a higher harmonic wave in terms of its use in a magnetic levitation induction linear motor. In addition, we present measurements of the propulsive and levitation forces generated by the modulated wave. When the order of the higher harmonic wave is 4, the basic wave mainly generates a propulsive force, while the higher harmonic wave generates a levitation force alone. Thus, the propulsive and levitation forces can be easily and almost independently controlled by changing the amplitude of the basic wave and that of the higher harmonic wave, respectively. When the order of the higher harmonic wave is 3 or 5, the forces can also be easily controlled, if the phase of the higher harmonic wave is the same between two phases. Index Terms--Higher harmonic wave, levitation force, linear motor, modulated wave, open core, propulsive force, two-phase electric source.