Effect of Magnetic Properties of Non-Oriented Electrical Steel on Characteristics of Interior-Permanent-Magnet Synchronous Motor

摘要

The torque characteristics and the motor efficiency of Interior-Permanent-Magnet synchronous motor (IPMSM), in which core materials were our conventional non-oriented electrical steel 35SX250 and our developed steel 35SXH300 with high permeability, were measured by motor test equipment. The torque characteristics of the motor with developed steel were superior to that of conventional steel. On the other hand, the effect of magnetic properties of electrical steels on motor efficiency was rather complicated. In the case of high speed condition such as 3000rpm, the efficiency of the conventional steel motor was superior to that of the developed steel motor. However, the efficiency of the developed steel motor was higher than that of the conventional steel motor at low speed condition such as 900rpm. As a result of motor loss separation analysis, the advantage of the efficiency of conventional steel motor at high speed condition was due to low core loss, while that of developed steel motor at low speed condition was due to low copper loss. These results mean that the developed steel is useful for motors under the condition of large ratio of copper loss to total motor loss such as high torque and low speed condition.