A novel wind energy system

A novel wind energy system is proposed and studied in this paper. An axial-flux permanent-magnet synchronous generator (AFPMSG) is directly coupled to a vertical-axis wind turbine (VAWT), which can be an H-Darrieus, Savonius, Hunt turbine, or others. The AFPMSG has an outer-rotor construction for convenient mounting to the turbine rotor structure. The coreless armature winding design eliminates cogging torque and unbalanced magnetic pull, giving smooth operation with low losses. Performance of a prototype generator is studied. The magnetic field distribution of the AFPMSG is studied using a two-dimensional finite element method (FEM) and analytical methods. By using the concept of image magnetic charges, we show that the normal component of flux density is reduced appreciably at the inner and outer circumferential regions.