Torque and Efficiency Improvement of High-Speed Cooling-Fan Motor

Abstract

  This paper presents torque and efficiency improvement of high-speed permanent magnet (PM) motors for cooling-fans from the view point of the rotor structure. The first candidate is surface permanent magnet (SPM) motor, which has bonded Nd-Fe-B polar anisotropic magnets in order to obtain large torque and low iron loss. The second one is interior permanent magnet (IPM) motor, which has a two-layer-type rotor in order to obtain large reluctance torque. The both PM motors are compared in terms of torque and efficiency by using three-dimensional finite element method (3D-FEM). The IPM motor, which demonstrates higher efficiency, is prototyped and demonstrates lager torque and higher efficiency in comparison with a previous cooling-fan motor.