Torque Ripple Reduction Using Hierarchical-like Fuzzy Controller of a Five-Phase Salient Pole Permanent Magnet Synchronous Motor Drive

The objective of this paper is to implement a hierarchical-like fuzzy controller of a five-phase salient pole permanent magnet synchronous motor (FP-PMSM) drive aiming to reduce the torque ripple. The fuzzy controller was developed as an intrinsically hierarchical controller, i.e., the controller controls both the speed and the pulsating torque through quadrature axis voltage. The speed control has priority over the torque ripple control. This feature is achieved by properly choosing the inputs and defining the fuzzy rules. The rules for torque ripple control are fired only when the speed has reached its desired value. This is possible only because of the speed sluggishness, against torque fastness, and the fuzzy controller fastness. One of the advantages of the fuzzy controllers, including the one proposed in this paper, is that it is developed without the need of the machine model. The paper is organized as follows: i) motivation and discussion of previous works, ii) system overview, iii) five-phase inverter SVPWM description, iv) description of the prototype composed by an 11 kW FP-PMSM, retrofitted from a three-phase PMSM, driven by a FP-IGBT VFI, 200 Vdc, and a mechanical load, v) experimental results. The experimental results show that the torque ripple using the PI controller is around 6.0 Nm peak-to-peak while using a fuzzy controller is around 2.0 Nm (3 times reduction).