Improvement of transverse flux linear induction motors performances with third order harmonics current injection

摘要

A noncontacting steel plate conveyance system using the transverse flux linear induction motor (TFLIM) is studied. The steel plate makes up the secondary of TFLIM. A combined control principle of levitation and propulsion for TFLIM is proposed. The output capacity of the power converter for control is limited by its maximum current, but the performance of TFLIM depends on its fundamental component. Then a third harmonic current injection scheme is considered for the drive system, in order to increase the fundamental component, keeping the value of the maximum current invariant. TFLIM characteristics are calculated both for the levitation and propulsion forces acting on the secondary steel plate, on the basis of a 3D electromagnetic field analysing program (J-MAG Studio). In comparison with a sinusoidal current excitation, the propulsion and levitation force of TFLIM increases by 33% and 37%, respectively, when the harmonic current injection level is optimized. Thus, the harmonic current injection scheme is shown to be an effective and practical mean to realize a steel plate conveyance system.