Electromagnetic design of an ultra‐high‐speed bearingless permanent magnet synchronous motor

Abstract Aiming at the problem of high‐speed motors being limited by multiple physical fields, which makes it difficult to achieve ultra‐high‐speed stable operation and develop towards higher speeds and higher power, an ultra‐high‐speed bearingless permanent magnet synchronous motor (UBPMSM) is proposed. Based on the mathematical model of suspension force for the bearingless permanent magnet motor considering the rotor eccentricity and load condition, the electromagnetic design method for UBPMSM is proposed. According to this method, the topology, torque system and suspension force system of a 10 kw 100k r/min UBPMSM are theoretically designed. The finite element method (FEM) is used to analyse the electromagnetic performance, which verifies the correctness of the proposed design method for UBPMSM. Further analysis and selection of winding span combinations are conducted to obtain better torque and suspension performance.