Comparative Study of Laminated Core Permanent Magnet Hybrid Stepping Motor with Soft Magnetic Composite Core Claw Pole Motor

This paper presents the comparison and analysis of cogging torque and core losses of permanent magnet hybrid (PMH) stepping motor made up of laminated steel core with claw pole (PM) motor made up of soft magnetic composite core. The material used as permanent magnet in both the machines is NdFeB. Basic analysis was done using equivalent magnetic circuit for both machines and refined analysis is carried on claw pole (PM) machine using finite element magnetic field analysis. Cogging torque is found to be double in claw pole machine than that of PMH machine. Core losses are more at normal frequencies and reduced to one-third at higher frequencies for soft magnetic core PM.