Cogging Torque Reduction Based on a New Pre-Slot Technique for a Small Wind Generator

Abstract

Cogging torque is a pulsating, parasitic and undesired torque ripple intrinsic of the design of a permanent magnet synchronous generator (PMSG), which should be minimized due to its adverse effects: vibration and noise. In addition, as aerodynamic power is low during start-up at low wind speeds in small wind energy systems, the cogging torque must be as low as possible to achieve a low cut-in speed. A novel mitigation technique using compound pre-slotting, based on a combination of magnetic and non-magnetic materials, is investigated. The finite element technique is used to calculate the cogging torque of a real PMSG design for a small wind turbine, with and without using compound pre-slotting. The results show that cogging torque can be reduced by a factor of 48% with this technique, while avoiding the main drawback of the conventional pre-slotting technique: the reduction of induced voltage due to leakage flux between stator teeth. Furthermore, through a combination of pre-slotting and other cogging torque optimization techniques, 84%, cogging torque can be eliminated for a given design.

Study and analysis the effect of variable applied voltage on SCIM performances based on FEA

“…Due to high power density, efficiency, high power factor and mall size, it becomes a good choice instead of other conventional motors. [1][2][3]. A study of the basic 1231 guidelines to develop a coupled FEM for the study of electromagnetic phenomena in I.M presented in [4].…”