Design and analysis of a new axial flux permanent magnet synchronous generator for wind

Abstract The paper deals with a new design of a low-speed disk permanent magnet axial flux synchronous machine for decentralized power generation, which has improved weight-size parameters. In the new design the value of the air gap value is reduced by removing all inter-coil connections from the gap and also a concentrated winding with a high winding coefficient is applied. A two-rotor prototype of this design is created (150 W, 83 V, 250 rpm) and its magnetic circuit and the concentrated windings arrangement are described, as well as the results of the machine experimental study. The 2D finite element analysis is used to determine the effect of the air gap value effect on the disk slotless generator parameters. The method of rational choice of the machine main dimensions and the parameters of its winding according to nominal data and electromagnetic loads limitations are presented. Comparison of parameters and characteristics of a 20-pole-pair 5 kW synchronous wind generator with the new design and cylindrical one with tangential magnetization is performed. The proposed slotless design exceeds the cylindrical one in efficiency and requires less material costs. The limitations are the higher value of the outer machine diameter and the required large magnets mass.