Calculation of Rotor Critical Speeds from Permanent Magnet Synchronous Machine

This paper presents a calculation method of damped critical speeds of anisotropic supporting rotor-bearing system from 1120kW Permanent Magnet Synchronous Machine (PMSM). Transfer matrix adding time factor in shifted QR algorithm is founded. As the whirling of the rotor of PMSM in 1500rpm directly results in dynamic off-center of itself, it produces unbalancing magnetic traction, which makes the critical speeds fall and vibration response increase further. Therefore, the calculation of mechanical and electrical coupling problem is the crucial problem of determining dynamic characteristics of anisotropic supporting rotor-bearing system of the PMSM.