Permanent Magnet Synchronous Motor Magnet Designs with Skewing for Torque Ripple and Cogging Torque Reduction

Author(s):  
R. Islam ◽  
I. Husain ◽  
A. Fardoun ◽  
K. McLaughlin
Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 362
Author(s):  
Shuhua Fang ◽  
Songhan Xue ◽  
Zhenbao Pan ◽  
Hui Yang ◽  
Heyun Lin

This paper proposes the use of a novel cylindrical arc permanent magnet synchronous motor (CAPMSM) in a large telescope, which requires high positioning accuracy and low torque ripple. A 2D finite element method was used to analyze the cogging torque of the CAPMSM. The CAPMSM can be an alternative for a rotating motor to realize direct drive. A new method is proposed to separate the cogging torque, Tcog, into the torque, Tslot, generated by the slotted effect and the end torque, Tend, generated by the end effect. The average torque and the torque ripple are optimized considering stator center angle, the angle between two adjacent stators and the unequal thickness of a Halbach permanent magnet. The torque ripple decreased from 31.73% to 1.17%, which can satisfy the requirement of tracking accuracy for large telescopes.


Author(s):  
Ravisankar B Et.al

Permanent magnet (PM) motors are rapidly replacing the squirrel cage induction motors for its energy efficient operation, smooth control and high power density. Although PM Motors are energy efficient, they are inherently affected by cogging torque and torque ripple. Magnetic alignment between teeth of stator and permanent magnet of rotors produce cogging torque. Torque ripple is a dynamic oscillation during steady-steady operation which leads to various mechanical anomalies like vibration, noise and rotor stress. Torque ripple is produced in PM motors because of non-sinusoidal distribution of flux, saturation, improper selection of slots etc., these ill effects will deteriorate the starting and steady-state performance of motors. So it is very vital to make analysis and prediction of cogging torque and torque ripples to make the motor more effective. Now a day's minimizing the torque ripples and cogging torque are gaining importance in PM motor designs. In this proposed work, the cogging torque analysis and torque ripple analysis of permanent magnet motor and line start permanent magnet motor has been done and reported.


2013 ◽  
Vol 712-715 ◽  
pp. 2757-2760
Author(s):  
Jun Li Zhang ◽  
Yu Ren Li ◽  
Long Fei Fu ◽  
Fan Gao

In order to deeply understand the characteristics of the permanent magnet synchronous motor direct torque control method, its mathematical models were established in the two-phase stationary coordinate system, the two-phase synchronous rotating coordinate system, and x-y stator synchronous rotating coordinate system. The implementation process of direct torque control method in varied stator winding connection was analyzed in detail. In order to improve the speed and torque performance of the permanent magnet synchronous motor, the direct torque control block diagram and the space voltage vector selection table were given. Finally, the summary and outlook of reducing torque ripple in the permanent magnet synchronous motor direct torque control methods.


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