Analysis and Calculation of Iron Loss in Electrical Motors With High Silicon Steel Considering Multi-Physics Coupling

High-silicon steel 10JNEX900 is often considered as a good core material for high-speed motors due to its low losses. However, cores are often operated under the multi-physics coupling (rotating and harmonic magnetic field, temperature, mechanical stress) resulting in variations in iron loss, which directly affects the modeling accuracy of the motor. In order to accurately predict the 10JNEX900 motor loss, this paper conducts iron loss tests under multi-physics coupling on two kinds of silicon steel materials, high silicon steel 10JNEX900 (6.5% Si) and conventional silicon steel ST100 (3.0% Si), and analyzed the differential change rule of 10JNEX900 loss. On this basis, the article proposes a model for calculating the iron loss of 10JNEX900 motor considering multi-physics coupling factors, and calculates the iron loss of silicon steel sheet. Meanwhile, the magnetic field, temperature field and stress field of the permanent magnet synchronous motor were calculated by the finite element method. The differences in motor performance before and after considering the multi-physics field factors are also compared. Finally, the motor prototype is fabricated and tested. The difference between the predicted and measured iron loss in the motor at no-load is lower than 10%.