A Study on Improvement Magnetic Torque Characteristics of IPMSM for Direct Drive Washing Machine

This paper presents a research on magnetic torque improvement of interior permanent magnet synchronous motor (IPMSM) for a direct drive washing machine by considering various barrier shapes. For the direct drive of washing machine, the IPMSM must have high magnetic torque at low speed in the laundry mode. However, the magnetic torque of it is decreased and torque ripple is also increased at the same time, when current phase angle is increased. By using finite element analysis (FEA), several characteristics such as d-, q-axis inductance, back electromotive force (EMF), average torque, torque ripple, and cogging torque are presented. Besides, high-temperature demagnetization which can occur in manufacturing time is considered. Finally, the analysis results are compared with experimental results to verify the proposed design.