Acceleration-Performance Optimization for Motors With Large Air Gaps

This paper presents an optimization-procedure yielding for minimal acceleration times for different speed ranges using the example of a magnetically levitated slice motor with a large air gap. The optimization is based on a set of analytical equations together with selected 3-D finite element method simulations with the aim to optimize both the stator geometry and the number of drive turns. It is shown that the use of 3-D instead of 2-D simulation tools is obligatory for motors with large air gaps for achieving sufficient simulation accuracy. The relevant equations for the optimization are derived, and the accuracy of the proposed method is verified by measurements on a prototype system.