Title :
Modelling and analysis of electromagnetic torque in direct drive PM machines with rotor eccentricity
Author :
Kimiabeigi, M. ; Zhu, Z.Q.
Author_Institution :
Dept. of Electron. & Electr. Eng., Univ. of Sheffield, Sheffield, UK
Abstract :
The influence of rotor eccentricity on torque oscillations as well as average output torque of permanent magnet (PM) machines with integral number of slots per pole per phase has been studied using 1-dimensional (1D) analytical modelling and 2-dimensional (2D) finite element (FE) method. It is shown that cogging and ripple torque are amplified by rotor eccentricity due to the contribution of new flux density components created by eccentricity, while this amplification follows a quadrature function against the eccentricity degree. Furthermore, it is shown that the average electromagnetic torque can be increased by rotor eccentricity provided that magnetic saturation is negligible. The analytical predictions have been validated by FE analysis of a direct drive PM machine.
Keywords :
electric drives; electromagnetic devices; electromagnetic oscillations; finite element analysis; permanent magnet machines; rotors; torque; 1-dimensional analytical modelling; 1D analytical modelling; 2-dimensional finite element method; 2D FE method; average output torque oscillation; cogging torque; direct drive PM machine; direct drive permanent magnet machine; electromagnetic torque; flux density component; magnetic saturation; quadrature function; ripple torque; rotor eccentricity; slot per pole per phase integral number; Average torque; direct drive; eccentricity; torque oscillations;
Conference_Titel :
Power Electronics, Machines and Drives (PEMD 2012), 6th IET International Conference on
Conference_Location :
Bristol
Electronic_ISBN :
978-1-84919-616-1
DOI :
10.1049/cp.2012.0278
