Nonlinear control of electric machines: an overview

Due to the increasing availability of improved power electronics and digital processors at reduced costs, there has been a trend to seek higher performance from electric machine systems through the design of more sophisticated control systems software. There exist significant challenges in the search for improved control system designs, however, since: the dynamics of most electric machine systems exhibit significant nonlinearities; not all state variables are necessarily measured; and the parameters of the system can vary significantly from their nominal values. In recent years, a wide range of nonlinear methods for feedback control, state estimation, and parameter identification have emerged, and some of these results are reviewed and summarized.<>