Robust fractional order proportion-plus-differential controller based on fuzzy inference for permanent magnet synchronous motor

Owing to the simplicity and effectiveness, the proportional-integral-differential (PID) controller is widely used in the control of permanent magnet synchronous motor (PMSM). However, the disadvantage of the PID controller is its poor capacity in dealing with system uncertainties. The authors propose a robust fractional order proportion-plus-differential (FOPD) controller for the control of PMSM. To enhance the robustness, the control effort of FOPD controller acts on an acted function (AF) instead of tracking error directly. A tuning method is used for the gains of FOPD controller and a fuzzy logic inference algorithm (FLIA) is designed to obtain the parameters of AF. Some simulation and experimental results show that the proposed control scheme not only achieves favourable tracking performance, but also is robust with regard to external load disturbance and parameter variation.