Abstract
This paper presents a method of increasing the load capacity of magnetic suspension system with a PID or zero-power controller. In the magnetic suspension systems, load capacity is determined by coil current and suspension gap. In the PID controlled system, the displacement is kept zero and the coil current increases when load is added to the floater. In the zero-power controlled system, the current is kept zero and the gap decrees. The load capacity is therefore determined by the current limit in the former and the gap limit in the latter. This paper shows that the load capacity can be increased by combining both the controls.
