Analysis of Characteristics of Attractive Type Magnetic Levitation System with 3.PHI. AC Electro-Magnets.

Abstract

This paper is investigating characteristics of an attractive type magnetic levitation system with 3φ AC electro-magnets. The system has iron rails with primary windings on the ground and levitation magnets with secondary windings placed on the levitated object, and the object is levitated by feed-back control of magnetically induced current of the levitation magnet. In this system, the levitated object has no part contacting the ground and needs no on-board battery.In the paper, dynamic and static characteristics of the AC levitation system with 3φ AC magnets are analyzed and a transfer function of the system is given. The transfer function is determined by the magnet constants which can measured by using the method to measure constants of a transformer. The dependency of the system characteristics and stability on the magnet and the feed-back constants are discussed based on the analysis. To investigate the validity of the analysis, an experiment has been performed by making a one-point support model system. Experimental results well agreed with the analytical results considering that the system is non-linear and has AC coupling circuit, and we consider that the analysis described in the paper is valid.