Multi-physics analysis and rotor loss optimization of high-speed magnetic suspension PM machine

To improve the overall performance of high-speed magnetic suspension PM machine and obtain the optimal design parameters, an electromagnetic filed, rotor dynamics and rotor strength analysis was conducted on a magnetic suspension machine (30 kW, 48 000 rpm), and a size optimization method based on such multi-physics analysis was put forward. Used ANSYS and ANSOFT to carry out modeling and finite element analysis on the motor, and then completed the integrated optimization designed by adopting the ISIGHT software, taking the impact of dimensional change on the rotor model and rotor strength into consideration, with the minimum rotor loss as the optimization goal, geometric dimension of the motor as the design variable, and dimension, magnetic performance and mechanical performance as the constraint conditions. After such optimization, rotor loss of the motor was decreased by 16.7%, with other performances in compliance with the design requirements. Then a back-to-back test and temperature rise test were carried out in the model machine based on the optimization design results. The test results verify the reasonability of such optimization design and correctness of the method put forward in this paper.