Rotor Synchronous Response Control: Approaches for Addressing Speed Dependence

Abstract

Three new approaches to the design of synchronous response controllers for magnetic-bearing- supported rotors operating over a range of speeds are developed. Previously reported methods have the disadvantage of requiring either on-line estimation or gain scheduling via a look-up table. Both of these approaches increase controller complexity and cost. The controllers presented herein are either robust to operating speed variation or are gain scheduled via a simple function. In either case, the implementation of the synchronous response control algorithm is greatly simplified and, in some cases, may be achieved with simple analog circuits. An example problem is considered, and four synchronous response controllers are synthesized. Extension of the synthesis methods to provide robustness with respect to plant uncertainty is straightforward and is briefly examined.