A New Concentrated Windings Surface Mounted Permanent Magnet Synchronous Machine for Wind Energy Application

The concentrated windings designs are often used in small BLDC motors as well as in AC servomotors due to their shorter end windings and smaller packing size. They are not yet frequently used in larger electrical machines due to concerns about torque density. For example, for a design with slot/ pole ratio of 1.5, the winding factor decreases to 0.866 which the penalty of smaller packaging size is translated to approximately 33.3% more copper losses as compared with a reference machine with winding factor of unity. In this paper, a new concentrated windings surface mounted permanent magnet machine for wind energy application with higher power density is proposed. The proposed machine utilizes 48 poles and 45 slots. The analysis shows while the proposed machine enjoys the privilege of shorter end windings and smaller packaging size, higher torque density is achieved through the winding factor of 0.952. This design with its novel pole and slot configuration, poses zero cogging torque and negligible torque ripple which these features make it a promising technology for wind energy applications. The mathematical model of the proposed machine is developed and is verified with finite element analysis