Investigation of flat and V-shaped magnets in interior permanent magnet machine for direct drive wind turbine application

This paper presents a systematic design comparison of an interior permanent magnet machine (IPMM) with a flat shaped and a V-shaped magnet rotor structure applicable for direct drive wind turbine. It also discusses various steps that were taken to minimize the cogging torque, torque ripple and the overall size of the machine using two dimensional finite element (FE) analysis. The torque ripple and cogging torque of the flat shaped IPMM were found to be lower than the V-shaped IPMM when the machine volumes are kept same. All the basic parameters and output characteristics for both the designs are compared using CEDRAT FLUX 2D FEA.