International Journal of Applied Electromagnetics and Mechanics 13 (2001/2002) 451–456 451 IOS Press Performance characteristics improvement of a PM disk motor by using soft magnetic composite material Goga Cvetkovski a , Lidija Petkovska a , Milan Cundev a and Sinclair Gair b a Sts. Cyril & Methodius University, Faculty of Electrical Engineering, P.O. Box 574, 1000 Skopje, Macedonia Tel.: +389 2 399 143; Fax: +389 2 364 262; E-mail: gogacvet@yahoo.co.uk b Napier University, School of Engineering, 219 Colinton Road, Edinburgh EH14 1DJ, UK Abstract. The paper presents a comparison of the magnetic field and magnetic characteristics of a PM disk motor with laminated magnetic stator open slot core, laminated magnetic stator closed slot core with soft magnetic composite and soft magnetic composite stator core. The data for this analysis is provided by a 2D FEM calculation of the magnetic field. After the proper modelling of the motor a calculation of the magnetic field for no load and current load is performed, for the three models. The results of the magnetic field distribution, air gap flux density distribution and the values of the magnetic and electric parameters for the three models are also presented. 1. Introduction The object applied in the research is a brushless three phase synchronous permanent magnet disk motor fed by an inverter and battery or fuel cell. The motor is a double sided axial field motor with two stators with 36 slots and a centred rotor with 8 skewed neodium-iron-boron permanent magnets. The stator cores of the permanent magnet disk motor (PMDM) have been made of wound strip cores with open stator slots. In this type of motor the slots are not easily placed in a laminated core since the laminations need to be spirally wound and the slots become progressively farther apart as the laminations occupy a greater diameter. For the PMDM prototype the slots were cut into the previously wound stator cores, which as a procedure brings a big risk of damaging the cores. The reduction of the torque pulsation due to the stator slot openings is very important due to the fact that this type of motor is designed for a direct wheel drive in electric vehicles. It is evident that the research should be focused on reducing the torque pulsation and reducing the complexity of the stator core production. 2. Soft magnetic composite materials application Powder metallurgy techniques have been in use for nearly three decades and their main application is as cores in the high frequency excitation range of magnetic circuit devices. In this, their relatively high permeability and low loss values at high frequencies, have provided significant cost and performance advantages over other materials, especially their isotropic characteristics along all three axes. Although 1383-5416/01/02/$8.00  2001/2002 – IOS Press. All rights reserved