Gain-scheduled PI speed controller for PMSM drive

In this paper, we propose a gain-scheduled scheme for a proportional-integral controller for speed control of a permanent-magnet synchronous motor (PMSM) drive. A conventional fixed-gain linear proportional-integral (PI) controller fails to provide satisfactory transient performance under varying operating conditions. In the proposed gain-scheduled scheme, the proportional and integral gains are allowed to vary within a pre-determined range and therefore alleviates the problems faced by the fixed-gain PI controller. The performance of the proposed scheme has been studied extensively through digital simulation studies for speed control application. Simulation results obtained so far show improvements in transient as well as steady-state responses over conventional fixed-gain PI controller.