A Nonlinear Method for Hybrid Electromagnetic Suspension

This paper mainly presents a nonlinear control method for hybrid electromagnetic suspension. Targeting to keep a constant distance between the stator and load, model is researched and controlled in the perpendicular direction. Windings are added into the model to control the disturbance force; at last the load will reach a stable state and be kept in the appointed position in the zero-power control mode which is only permanent magnets´ attractive force suspend the levitated body and the steady currents of the electromagnets converge to zero by adjusting the levitation gap length corresponding to its loaded mass. The usefulness of the method is that using springs to analogize the electromagnet system on the base of nonlinear character in common, and calculate the stable position with the Lyapunov functions. So it is a novel method to solve the magnet levitation problem effectively with approximately zero-power in one dimension. The approach is demonstrated to be effective to control the nonlinear system by simulation