Minimization of cogging torque in permanent magnet motors by teeth pairing and magnet arc design using genetic algorithm

Eom, Jae-Boo; Hwang, Sang-Moon; Kim, Tae‐Jong; Jeong, Weui-Bong; Kang, Beom-Soo

doi:10.1016/s0304-8853(01)00053-1

Cited by 7 publications

(12 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is also simple and cost effective with minimal effects on the machine performance. In [17], teeth pairing and optimizing the pole-arc ratio reduced cogging torque by 99.2% in a linear analytical machine model. Slotopenings were displaced to ensure the cancellation of cogging torque.…”

Section: Ieee Transactions On Industrial Electronicsmentioning

confidence: 99%

“…In [4] the effect of the slot-openings on both parallel and trapezoidal-teeth stators was mentioned but not analysed, while in [23] the effect of slot-openings on trapezoidal-teeth stator was analysed. In most cases as proposed in [4], [17], [18] and [24], slot-openings and slots are often displaced as a way of mitigating cogging torque, but not by optimizing their width. It will be shown that the slot-opening width is very significant in the mitigating cogging torque in axial-flux PM machines, with parallel-teeth stators.…”

Section: Ieee Transactions On Industrial Electronicsmentioning

confidence: 99%

See 1 more Smart Citation

Influence of Slot Openings and Tooth Profile on Cogging Torque in Axial-Flux PM Machines

Wanjiku

Khan

Barendse

et al. 2015

IEEE Trans. Ind. Electron.

View full text Add to dashboard Cite

Slotted axial-flux machines have excellent power and torque densities. However, it is difficult to reduce their cogging torque due to the complexity associated with implementing classical techniques. In this paper, slot-opening widths and tooth-profiles will be shown to be significant in mitigating cogging torque in these machines. In particular, varying the slot-opening reduced it by 52 %, whereas a paralleltooth (rectangular) profile lowered it by 24 %, when compared to a conventional trapezoidal-tooth profile. An analytical quasi 3-D analysis was formulated and used to analyse and determine cogging torque. It was validated numerically and experimentally. Its versatility is in its ability to analyse different shapes of poles and slot-openings, which can be extended to model airgap nonuniformities. The paper also presents cogging torque minimization techniques that maintain the ease of manufacture of the parallelteeth stator. Experimental results showed a 73 % and 48 % reduction in cogging torque; achieved by the use of alternating pole-arcs and skewed poles. NOMENCLATURE aSlot-opening depth 0278-0046 (c)

show abstract

Section: Ieee Transactions On Industrial Electronicsmentioning

confidence: 99%

Section: Ieee Transactions On Industrial Electronicsmentioning

confidence: 99%

Influence of Slot Openings and Tooth Profile on Cogging Torque in Axial-Flux PM Machines

Wanjiku

Khan

Barendse

et al. 2015

IEEE Trans. Ind. Electron.

View full text Add to dashboard Cite

show abstract

“…The energy change in the PMs and iron is minimal compared to that of air. It is given as [8], [9] T I T…”

Section: Techniques Of Minimizing Cogging Torque In Axial-flux Pmentioning

confidence: 99%

“…For instance, teeth pairing, interpole design and teeth notching reduce G NL , while magnet shaping and pole-arc design reduce B NL . Increasing the cogging frequency, N L by the proper selection of the slot-pole combination reduces both G NL and B NL [9].…”

Section: Techniques Of Minimizing Cogging Torque In Axial-flux Pmentioning

confidence: 99%

“…Methods of mitigating cogging torque include: optimizing the pole-arc ratio, varying the PM pole shape, skewing of stator teeth and/or rotor PMs, magnet or pole shifting, alternating the PM pole-arc ratio, optimizing the pole-slot combination, teeth-pairing, dummy slots, varying the radial shoe depth, control strategy and graded airgaps [5], [8], [9], [10]. Most of these methods are elaborated in [5].…”

Section: Techniques Of Minimizing Cogging Torque In Axial-flux Pmentioning

confidence: 99%

See 1 more Smart Citation

Minimization of cogging torque in a small axial-flux PMSG with a parallel-teeth stator

Wanjiku

Jagau

Khan

et al. 2011

2011 IEEE Energy Conversion Congress and Exposition

View full text Add to dashboard Cite

A stator with a steel core is well suited for small, low speed PM machines, where core losses are much lower than copper losses. However, a slotted stator introduces cogging torque. A stator with parallel-teeth inherently lowers cogging torque but there is need to further reduce it. This is particularly important in wind generators since it raises the cut-in wind speed, thereby lowering the energy captured yield for a given installed capacity. Pulsating torques also produces noise and mechanical vibrations which accelerates the wear of the machine and its support structure. This paper presents some effective methods of minimizing cogging torque, which have minimal effects on the performance of the machine. Three PM rotor configurations were considered, which include: a pole-arc ratio of 0.80, alternating pole-arcs of 0.61 and 0.80, and skewed PM poles with a skew one slot-pitch. The 3 rotor configurations were simulated numerically using 3D Finite Element Analysis (FEA) and tested experimentally with the same stator. The machine topology with a rotor pole-arc ratio of 0.80 was used as the reference design. From the experimental results, the alternating pole-arcs effectively reduced coggingtorque by 73% whereas the skewed poles reduced it by 48%. The 3D-FEA and experimental cogging torque results are also comparable. The paper also compares cogging torque reduction techniques which are well suited for a parallel-teeth stator.Index Terms-Axial-Flux, Cogging torque, Finite element analysis, Parallel-teeth, Permanent Magnet, Ripple torque 978-1-4577-0541-0/11/$26.00 ©2011 IEEE

show abstract

Design, analysis, and fabrication of a direct drive permanent NdFeB magnet synchronous motor for precision position control

Hariri

Aliabad

Ghafarzadeh³

et al. 2020

IET Electric Power Applications

View full text Add to dashboard Cite

Direct drive motors have the excellent ability for precision position control due to their direct connection to load and elimination of the gearbox and pulley backlash. Among the direct drive motors, permanent NdFeB magnet synchronous motors (PMSMs) are the best choice for control systems due to their high efficiency, high power density, good dynamic behaviour, and excellent controllability. This study deals with the design, analysis, and fabrication of a direct drive PMSM for precision position control. To reach this aim, the designed motor should have very low cogging torque and torque ripple to avoid the motor deviation at the target point. To achieve these purposes, at first, a suitable combination of slot and pole has been selected for the motor and then the optimum shape of the magnets has been obtained by using the 2D finite element method. For the magnet shape, two important parameters of the magnet are optimised simultaneously. The designed motor has been fabricated and tested. Both simulation and experimental results show that the designed motor has a very good performance as the point of cogging torque and torque ripple views. Also, the experimental results validate the theoretical calculations.

show abstract

Minimization of cogging torque in permanent magnet motors by teeth pairing and magnet arc design using genetic algorithm

Cited by 7 publications

References 3 publications

Influence of Slot Openings and Tooth Profile on Cogging Torque in Axial-Flux PM Machines

Influence of Slot Openings and Tooth Profile on Cogging Torque in Axial-Flux PM Machines

Minimization of cogging torque in a small axial-flux PMSG with a parallel-teeth stator

Design, analysis, and fabrication of a direct drive permanent NdFeB magnet synchronous motor for precision position control

Contact Info

Product

Resources

About