A Stable Nonlinear Observer Design for Permanent-Magnet Synchronous Motors

Abstract The application of vector control techniques in ac drives demands accurate position and speed feedback information for the current control and servo control loops. This paper describes the design of a stable speed observer system suitable for use with the permanent-magnet synchronous motors (PMSM) as a software transducer. The observer is developed from the dq model of the machine. A technique employing state detection and eigenvalues confinement is used to achieve global stability and consistent convergency of the observer system.