Affiliations: [a] State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, Xi’an, China
Correspondence:
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Corresponding author: Haipeng Geng, School of Mechanical Engineering, Xi’an Jiaotong University, No. 28, Xianning West Road, Xi’an 710049, Shaanxi, China. E-mail: genghaipeng@mail.xjtu.edu.cn
Abstract: The electromagnetism and rotor dynamics have been drawing great research interest due to their significance in the design of the high speed permanent magnet synchronous motor. However, it is challenging but essential to study the rotor supported by air foil bearings with cylindrical permanent magnet. Here the approach is reported to analyze a high speed PMSM rotor at the rating of 28.5 kW and 96,000 rpm. Through the analytic method and the finite element simulation, the expression for the magnetic flux density is obtained. Based on the rotor-bearing system discrete model, the critical speed is calculated by Campbell diagram. It comes to the conclusion that the radius and length of cylindrical permanent magnet is reciprocally related to the magnetic flux density and critical speed values. Finally, results of the PMSM experimental device operating at 96,000 rpm are represented by rotor frequency spectrum and orbit diagram.
Keywords: High speed motor, cylindrical permanent magnet, magnetic field, rotor critical speed, air foil bearing
