LPV Gain-Scheduled Output-Feedback Tracking Control for PMSMs with Inexact Rotor Position Measurement

In this paper, a novel gain-scheduled output-feedback (GSOF) controller is designed to address the rotor speed tracking issue for permanent magnet synchronous motors (PMSMs) with inexact rotor position measurement. The PMSMs speed tracking control issue is transformed to study the LPV system control design issue in nonlinear torque modulation without direct-quadrature transformation. By choosing the rotor position as scheduling parameters, a kind of LPV GSOF controller is proposed to stabilize the tracking error system. Affected by external disturbances or faults in the position sensors, exact values of rotor position may not be available for the design of LPV GSOF controller. By using the Lyapunov function approach, sufficient conditions with less conservatism are obtained with the line search, such that the corresponding error systems are globally uniformly exponentially stable and satisfy an upper bound of l(2)-gain performance indexes. Finally, the effectiveness and applicability of the developed approaches are validated via a class of PMSMs system.