ELECTROMAGNETIC TORQUE RIPPLE MINIMIZATION OF SLOTTED DOUBLY-SALIENT-PERMANENT-MAGNET GENERATOR FOR WIND TURBINE APPLICATIONS

The aim of this work is to reduce the torque ripple of a low-speed/high-torque Doubly Salient Permanent Magnet (DSPM) generator for wind turbine applications. To do this, a combined design and control-based approaches are set up to improve the overall machine performance. The design-based approach helps to develop a form of small stator/rotor teeth combination, focusing on the shapes and dimensions of the teeth that will minimize torque ripple. On the other hand, in the second approach, a control technique is designed. It employs indirect torque control (Torque Sharing Function: TSF), including a PI-controller with gains adjusted continuously for regulating the reference current. The obtained results show that by combining these two approaches, the ripple rate of the electromagnetic torque for the studied DSPM is reduced to a minimum when the teeth shapes are trapezoidal in both the stator and rotor, and the command approach also allows an improvement in the total torque shape, such that the ripple rate decreases by about 96%.