Differential-geometric methods for control of electric motors

Abstract

The differential-geometric techniques of nonlinear control developed over the last 20 years or so include static and dynamic feedback linearization, input–output linearization, nonlinear state observers and disturbance decoupling. The theory has now reached a level of maturity where control practicioners are making effective use of the techniques for electric motors. Indeed, DC and AC motors have well-defined nonlinear mathematical models which often satisfy the structural conditions required of the differential-geometric theory. In this paper, the application of various differential-geometric methods of nonlinear control is shown by way of examples including DC motors (series, shunt and separately excited), induction motors, synchronous motors and DC–DC converters. A number of contributions are surveyed which show the benefits of the methods for the design of global control laws by systematic means. © 1998 John Wiley & Sons, Ltd.