Study the Combining Magnet Edge Shaping and Dummy Slot on the Performance of PMG for Wind Power Applications

Abstract

The effects of the shaping of magnet edge combining with dummy slots in stator core are studied in this paper. A permanent magnet generator is one of the electrical machine types greatly implemented in engineering and science applications. The permanent magnet generator performance refers to normal and tangential flux density and cogging torque. They can be forecasted depend on the quality and quantity of the distribution of the flux magnetic air gap. The most critical issue for the applications in the permanent magnet generator that needs to be contemplated is the value of cogging torque. The cogging torque is produced by the magnetic flux force from the magnet in the rotor core to the slot opening in the stator core. It is due to both the density of normal flux and the density of tangential flux in the air gap. Since many factors in a very stage influenced to produce the cogging torque, includes structure, material, and imperfection in manufacturing, hence the cogging torque in a permanent magnet generator is one of the difficult tasks to be reduced, especially for integral slot numbers. This work focused on the probe of magnet structure on the permanent magnet generator performance. In the study, a permanent magnet generator of 24 slot/ 30 pole has been chosen. By applying the finite element analysis of FEMM, it has been found that the tangential flux density can be reduced effectively. As an outcome, the cogging torque of the permanent magnet generator becomes decline, leads to the performance of the machine can be increased. The cogging torque of the permanent magnet generator with combining the shape of the magnet edge and dummy slot in the core of the stator can be brought down to 99.35 % contrasted with the initial structure..