Optimum magnetic bearing design considering performance limitations

Magnetic bearings are subject to three practical performance limitations: the peak force capacity, force slew rate limitation, and displacement sensitivity. In conventional designs, we usually first design a feasible bearing, and then investigate these three limitations. Unfortunately, one usually fails to design the most suitable magnetic bearing in actual cases. In this paper, a methodology for dealing with the performance limitations through the concept of optimum design is presented. The objective functions are to maximize the force slew rate limitation and to minimize the displacement sensitivity under several design constraints. Using the optimization solver software package, we developed a systematic method for determining the characteristics of magnetic hearings. By considering the performance limitations and design constraints, we achieve a better design than that produced using the conventional trial-and-error method.