Fuzzy Logic Speed Controller with Adaptive Voltage Feedback Controller of Permanent Magnet Synchronous Machine

In this paper, based on a non-salient permanent synchronous machine (PMSM), the adaptive control parameter of the voltage feedback controller used for flux weakening is firstly obtained in the torque control mode. However, in the speed control mode, the speed controller could induce more ripples in the current command, which consequently leads to more voltage ripples. It also indicates that voltage ripples vary with operation regions. Due to the limited voltage control margin, the increased voltage ripples deteriorate flux-weakening performance and may cause oscillation. In order to obtain both fast dynamics and less steady state ripples especially in the flux-weakening region, a simple adaptive fuzzy logic (FLC) speed controller is designed and compared with conventional proportional and integral (PI) speed controller. Experiments verify that the system with adaptive FLC can achieve both fast dynamics and less steady state ripples. Consequently, DC-link voltage utilization and flux-weakening capability can be further increased.