Permanent magnet BLDC Motor designs with skewing for torque ripple and cogging torque reduction

2016 ◽  
Author(s):  
Bui Dinh Minh ◽  
Student Member IEEE
Keyword(s):  
Permanent Magnet ◽  
Torque Ripple ◽  
Bldc Motor ◽  
Cogging Torque

Reduction in Cogging Torque and Flux per Pole in BLDC Motor by Adapting U-Clamped Magnetic Poles

2017 ◽  
Vol 8 (1) ◽  
pp. 297 ◽  
Author(s):  
M. Arun Noyal Doss ◽  
S. Vijayakumar ◽  
A. Jamal Mohideen ◽  
K. Sathiah Kannan ◽  
N.D. Balaji Sairam ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Motor Performance ◽  
Torque Ripple ◽  
Direct Impact ◽  
Bldc Motor ◽  
Magnetic Pole ◽  
Element Analysis ◽  
Cogging Torque ◽  
Different Shapes ◽  
Magnetic Poles

A Permanent Magnet BLDC motor is designed for reduction in cogging torque and flux per pole. The cogging torque causes direct impact in permanent magnet BLDC motor performance by causing torque ripple problems. This paper proposes a new method for reducing cogging torque by adapting to U-clamped magnetic poles. Finite Element Analysis (FEA) is used to calculate the cogging torque and the flux per pole for different shapes of magnetic pole. It can be shown that the cogging torque could be greatly reduced by adapting to U-clamped magnetic poles. At the same time it is found that the flux per pole is also considerably reduced. The effectiveness of the proposed method is verified by comparing the cogging torque and flux per pole for various designs available in the literature.

scholarly journals Analysis of Torque Ripple and Cogging Torque Reduction in Electric Vehicle Traction Platform Applying Rotor Notched Design

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3053 ◽  
Author(s):  
Myeong-Hwan Hwang ◽  
Hae-Sol Lee ◽  
Hyun-Rok Cha
Keyword(s):  
Permanent Magnet ◽  
Torque Ripple ◽  
Field Analysis ◽  
Permanent Magnet Motors ◽  
Primary Methods ◽  
Cogging Torque ◽  
Electric Cars ◽  
Electric Control ◽  
Interior Permanent Magnet ◽  
Rotor Shape

Drive motors, which are used in the drive modules of electric cars, are interior permanent magnet motors. These motors tend to have high cogging torque and torque ripple, which leads to the generation of high vibration and noise. Several studies have attempted to determine methods of reducing the cogging torque and torque ripple in interior permanent magnet motors. The primary methods of reducing the cogging torque involve either electric control or mechanical means. Herein, the authors focused on a mechanical method to reduce the cogging torque and torque ripple. Although various methods of reducing vibration and noise mechanically exist, there is no widely-known comparative analyses on reducing the vibration and noise by designing a notched rotor shape. Therefore, this paper proposes a method of reducing vibration and noise mechanically by designing a notched rotor shape. In the comparative analysis performed herein, the motor stator and rotor were set to be the same size, and electromagnetic field analysis was performed to determine a notch shape that is suitable for the rotor and that generates reasonable vibration and noise.

The Method Pole of Width Modulation Reducing Cogging Torque in Permanent Magnet Motor

2012 ◽  
Vol 433-440 ◽  
pp. 4201-4206
Author(s):  
Yue Jun An ◽  
Wen Qiang Zhao ◽  
Li Ping Xue ◽  
Hong Liang Wen ◽  
Guo Ming Liu
Keyword(s):  
Permanent Magnet ◽  
Torque Ripple ◽  
Experimental Result ◽  
Testing System ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Motor ◽  
Surface Type ◽  
Angle Sensor ◽  
Cogging Torque ◽  
Simulation Results

Cogging torque is one of the most important parameters of permanent magnet motors, which causes torque ripple, vibration and noise. This paper describes the mechanism of cogging torque, introduces several methods of reducing cogging torque and points out the advantage of novel magnet arrayed permanent magnet motor in reducing cogging torque. Ansoft software is used to build the simulation of conventional surface-type permanent magnet motor and novel magnet arrayed permanent magnet motor and to calculate their cogging torque. a cogging torque testing system which included the angle sensor, permanent magnet motor, torque wrenches and other components are tested two different structures motors’ cogging torque .The experimental result is consistent with the simulation results, it shows that the method of novel magnet arrayed permanent magnet motor reducing cogging torque is correct. The new method compare with the same specification on the surface of permanent magnet motor can reduce more cogging torque.

scholarly journals Comparison of Three Analytical Methods for the Precise Calculation of Cogging Torque and Torque Ripple in Axial Flux PM Machines

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Ahmed Hemeida ◽  
Bert Hannon ◽  
Hendrik Vansompel ◽  
Peter Sergeant
Keyword(s):  
Permanent Magnet ◽  
Lateral Force ◽  
Torque Ripple ◽  
Analytical Models ◽  
Permanent Magnet Synchronous Machines ◽  
Axial Flux ◽  
Cogging Torque ◽  
Precise Calculation ◽  
Analytical Tools ◽  
2D And 3D

A comparison between different analytical and finite-element (FE) tools for the computation of cogging torque and torque ripple in axial flux permanent-magnet synchronous machines is made. 2D and 3D FE models are the most accurate for the computation of cogging torque and torque ripple. However, they are too time consuming to be used for optimization studies. Therefore, analytical tools are also used to obtain the cogging torque and torque ripple. In this paper, three types of analytical models are considered. They are all based on dividing the machine into many slices in the radial direction. One model computes the lateral force based on the magnetic field distribution in the air gap area. Another model is based on conformal mapping and uses complex Schwarz Christoffel (SC) transformations. The last model is based on the subdomain technique, which divides the studied geometry into a number of separate domains. The different types of models are compared for different slot openings and permanent-magnet widths. One of the main conclusions is that the subdomain model is best suited to compute the cogging torque and torque ripple with a much higher accuracy than the SC model.

Effect of Additional Harmonics of Driving Current on Torque Ripple and Unbalanced Magnetic Force of the BLDC Motors With Stator and Rotor Eccentricities

2014 ◽  
Author(s):  
S. J. Sung ◽  
G. H. Jang ◽  
K. J. Kang ◽  
J. Y. Song
Keyword(s):  
Magnetic Force ◽  
Torque Ripple ◽  
Bldc Motor ◽  
Cogging Torque ◽  
Driving Current ◽  
Rotor Eccentricity ◽  
Commutation Torque Ripple

This paper investigates the characteristics of the torque ripple and UMF in the BLDC motor with stator and rotor eccentricities due to additional harmonics of the driving current. Torque ripple can be divided into cogging torque due to the interaction between poles and slots, and commutation torque ripple due to driving current. Additional harmonics of driving current affect the characteristics of torque ripple. UMF is not generated in rotational symmetric motors with respect to pole, slot and winding configurations. However, stator and rotor eccentricities of BLDC motors generate additional harmonics on cogging torque and UMF. This research theoretically and numerically investigates the effects of driving current on the torque ripple and UMF of a BLDC motor with rotor and stator eccentricities. It shows that additional harmonics of the driving current, the stator eccentricity, and the rotor eccentricity independently affect the torque ripple. It also shows that additional harmonics of the driving current generate additional harmonics in UMF if BLDC motors have the stator or rotor eccentricities.

scholarly journals Low cogging torque design and simplified model-free predictive current control for radial-flux dual three-phase permanent magnet electric machines

2019 ◽  
Vol 11 (12) ◽  
pp. 168781401989164
Author(s):  
Hsing-Cheng Yu ◽  
Hung-Wei Lai ◽  
Li-Jhen Chen ◽  
Cheng-Kai Lin
Keyword(s):  
Permanent Magnet ◽  
Control Method ◽  
Torque Ripple ◽  
Electric Machines ◽  
Current Control ◽  
Simplified Model ◽  
Cogging Torque ◽  
Model Free ◽  
Radial Flux ◽  
Three Phase

This study presents two improved designs of eccentric-shaped permanent magnets and teeth-shaped stators in radial-flux dual three-phase permanent magnet electric machines to reduce cogging torque and torque ripple. The finite element analysis (ANSYS Electromagnetics) has been adopted in simulation, and real radial-flux dual three-phase permanent magnet electric machines have been fabricated in experiment to verify the study. Using the radial-flux dual three-phase permanent magnet electric machines in electric machine systems can improve the reliability and obtain higher output torque. In electrical drives and control, a simplified model-free predictive current control method has been proposed and implemented to drive the radial-flux dual three-phase permanent magnet electric machines, and the control law has been achieved by a TMS320F28377S microcontroller of Texas Instruments. The simplified model-free predictive current control method is senseless to parameter variations and back electromotive force of the permanent magnet electric machines, and only needs current sensors to detect six-phase current. The optimal one has been chosen by 14 various switching modes, which has the minimum cost function, and then the converter can be directly driven and controlled in the next sampling period. The features of the simplified model-free predictive current control method can reduce the algorithm calculation and avoid the defect of conventional model-based predictive current control scheme. A proportional-integral speed controller has also been designed to achieve the speed response of the fixed-speed tracking effect. Finally, the feasibility and effectiveness of the proposed simplified model-free predictive current control method for the dual three-phase permanent magnet electric machines can be verified in the experimental and quantitative results.

Sign in / Sign up

Export Citation Format

Share Document