Investigation Cogging Torque of PMM with rotor and Stator optimization for renewable energy application

Abstract

This paper proposes the cogging torque reduction by using the optimization of the slotting method on the stator and the cutting edge of the rotor side magnet of the Permanent Magnet Machiene (PMM), of the Synchrounous Generator (PMSG). Here, the effect on the cross-sectional area of the magnetic poles and the additional width of the slot opening will lead to an improvement in the reduction of cogging torque for the investigated of the machine. The proposed machine has 6 poles and 18 slots with a fixed slot opening widths on the stator and modified magnetic poles on the rotor. The software used to investigate and analyze the saturation of the induced cores in the stator and rotor of machine is the magnetic finite element method (FEMM 4.2). The most cost-effective method to minimize the presence of cogging torque of any PMSG is to conduct the modification of the rotor where the magnets are located and modify the stator structure despite the complexity and cost of manufacturing the stator. Here, the cutting of magnetic edge structure using a simple cutting method is implemented. This is a different method from that already widely implemented for cutting the edge of the magnet surface. The simulation results show that the PMSG cogging torque by cutting the magnetic edge and adding a dummy slot can significantly minimize the cogging torque. It is found that the cogging torque reduction is 99.47 percent. This condition as the low cogging torque and low PMG speed can be used for reference design and PMSG construction for renewable energy plants such as in geothermal power plants.