Robust stabilizing regions of fractional-order PI controllers for permanent magnet synchronous motor control system

Abstract

The application of fractional order calculus in motor control systems has got much attention recently, and one of the major research is using fractional-order PIλDμ controllers instead of integral-order PIλDμ controllers. Moreover, there are many approaches to obtain the suitable parameters of fractional-order PIλDμ controllers, commonly according to different performance indexes or amplitude and phase margin conditions. This paper presents a graphical approach to determine the stabilizing regions of fractional-order PIλ controllers, for robust speed control of the Permanent Magnet Synchronous Motors. Based on D-decomposition method, the stabilizing regions in terms of the real root boundary(RRB) curves, complex root boundary(CRB) curves and infinite root boundary(IRB) lines are investigated for a given stability degree. Compared with the well-tuned PI controller, experiment results verify that the fractional-order PIλ controller has better effects on improving robustness of system against the disturbances.