Improvement of rotor structure of concentrated surface permanent magnet synchronous motor

Abstract

A new surface permanent magnet synchronous motor is developed by using concentrated permanent magnet arrangement. In this motor, the same magnetic poles of the assembling permanent magnets are faced to each other to generate larger magnetic flux density in the air gap. We call this the concentrated surface permanent magnet synchronous motor (CSPMSM). In order to realize higher torque and lower cogging, we examined to generate larger amplitude of sinusoidal magnetic flux in the air gap by changing the radius of rotor and the thickness of magnets. In the next step, we suggested a combination of the radial neodymium magnets and the circumferential ferrite magnets. We called this ¿hybrid type CSPM¿ (HCSPM). Their torque characteristics are analyzed with the finite element method and compared in detail.