Research and Experiments on Electromagnetic Field Induced by Two Coaxial Solenoid Coils of Axially Mag-lev Driving Needle

The movement of mag-lev driving needle depends on the interaction of magnetic fields between two solenoid coils and magnet. Inside single cylinder, two solenoid coils are placed vertically and coaxially while the magnet is laid at the bottom of the needle base. Based on magnetic-levitation theory and Biot-Savart Law, this paper taking into account the impacts of mutual inductance caused by double coils analyzed and computed magnetic force when these two coaxial coils were separated into different air-gap heights. By using Gauss meter to measure the magnetic field induced by two coils, we attains that the measuring data accords well with computing results. Besides, the electromagnetic-permanent driving model has been built through electromagnetic coupling module in ANSYS, and through FEM simulation, the curve of electromagnetic force exerted on the magnet as the air-gap height was achieved, and the magnetic field distribution map of this model was also attained.