scholarly journals Design and Performance Assessment of a Small-Scale Ferrite-PM Flux Reversal Wind Generator

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5565
Author(s):  
Bharathi Manne ◽  
Malligunta Kiran Kumar ◽  
Udochukwu B. Akuru
Keyword(s):  
Rare Earth ◽  
Wind Energy ◽  
Permanent Magnet ◽  
Torque Ripple ◽  
Small Scale ◽  
Cogging Torque ◽  
Flux Reversal ◽  
Wind Generator ◽  
Rotor Pole ◽  
Flux Reversal Machine

Currently, there is increasing research interest in harnessing wind energy for power generation by means of non-conventional electrical machines e.g., flux-reversal machines. The flux reversal machine is usually designed using scarce rare–earth permanent magnet material which may be unattractive in terms of machine cost. In this study, an attempt is made to re-design the flux reversal machine with non-rare-earth ferrite permanent magnet for wind energy applications. Because these machines possess high cogging torque, which results in vibration and noise, that are detrimental to the machine performance, especially at low speeds, a novel combined skewed and circumferential rotor pole pairing method is developed. The proposed cogging torque reduction method is implemented in 2-dimensional finite element analysis modeling and comparatively analyzed with other existing stand-alone methods viz., skewing, and rotor pole pairing. The results show that the proposed method led to 94.8% and 71% reduction in the cogging torque and torque ripple compared to the reference generator, respectively. However, the calculated torque density is reduced by 13%. Overall, the electromagnetic performance of the proposed ferrite PM machine exhibits desirable qualities as an alternative design for the direct drive wind generator.

scholarly journals The effect of static and dynamic eccentricities on the performance of flux reversal permanent magnet machine

2020 ◽  
Vol 11 (2) ◽  
pp. 634
Author(s):  
Ahlam Luaibi Shuraiji
Keyword(s):  
Permanent Magnet ◽  
Magnetic Force ◽  
Torque Ripple ◽  
Operating Conditions ◽  
Flux Reversal ◽  
Three Phase ◽  
Rotor Pole ◽  
Dynamic Eccentricity ◽  
Static Eccentricity ◽  
Undesirable Feature

This study investigates the effect of static and dynamic eccentricities on the performances of flux reversal permanent magnet (FRPM) machine with even rotor pole number, i.e. FRPM machine with 12/10 stator/rotor combination. No-load and load performances of the machine are investigated under three rotor operating conditions including centricity, static eccentricity and dynamic eccentricity. The investigation has been carried out using 2D-FEA. It has been revealed that the 12/10 FRPM machine under normal operating condition has no unbalanced magnetic force, due to the even pole number of the rotor. On the other hand, such undesirable feature would be presented in the 12/10 FRPM machine as a result of the existing of static and dynamic eccentricities.  Both static and dynamic eccentric machines exhibit unbalanced three-phase flux linkage as well as back-EMF.  Moreover, three operating conditions of the investigated machine have the same fundamental cogging torque harmonic. However, low order harmonics are existed in the static and dynamic centric machines and are not found in the centric machine. Furthermore, about 16% less torque ripple delivered by the centric machine compared with both static and dynamic counterparts.

scholarly journals Design of dual rotor axial flux permanent magnet generators with ferrite and rare-earth magnets

2020 ◽  
Vol 33 (4) ◽  
pp. 553-569
Author(s):  
Jawad Faiz ◽  
Tohid Asefi ◽  
Mohammad Khan
Keyword(s):  
Rare Earth ◽  
Permanent Magnet ◽  
Three Dimensional ◽  
Torque Ripple ◽  
Population Based ◽  
Axial Flux ◽  
Energy Applications ◽  
Rotor Pole ◽  
Mass Minimization ◽  
Population Based Algorithm

This article addresses dual rotor axial flux Ferrite permanent magnet (PM) generator, as an alternative to a surface mounted and spoke types Nd-Fe-B generator which have concentrated windings. The performance parameters of all generators, particularly the efficiency, are identical. The design objective function is the generators mass minimization using a population-based algorithm. To predict the performance of the generators a finite element (FE) technique is applied. Besides, the aims of the design include minimizing cogging torque, examining different rotor pole topologies and different pole arc to pole pitch ratios. Three-dimensional FE technique is employed. It is shown that the surface mounted Ferrite generator topology cannot develop the rated torque and also has high torque ripple. In addition, it is heavier than the spoke type generator. Furthermore, it is indicated that the spoke type Ferrite PM generator has favorable performance and could be an alternative to rare-earth PM generators, particularly in wind energy applications. Finally, the performance of the designed generators is experimentally verified.

scholarly journals Wind Generator Impedance Matching in Small-Scale Passive Wind Energy Systems

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 22558-22568
Author(s):  
Casper J. J. Labuschagne ◽  
Maarten J. Kamper
Keyword(s):  
Wind Energy ◽  
Impedance Matching ◽  
Energy Systems ◽  
Small Scale ◽  
Wind Generator ◽  
Wind Energy Systems

Cogging Torque Analysis of Novel Dual-Rotor Axial Field Flux-Switching Permanent Magnet Machine

2013 ◽  
Vol 416-417 ◽  
pp. 276-280 ◽  
Author(s):  
Li Hao ◽  
Ming Yao Lin ◽  
Da Xu ◽  
Xing He Fu ◽  
Wei Zhang
Keyword(s):  
Permanent Magnet ◽  
Design Parameters ◽  
Original Design ◽  
Axial Field ◽  
Cogging Torque ◽  
Tooth Width ◽  
Rotor Pole ◽  
Torque Analysis ◽  
Slot Opening ◽  
3D Finite Element Method

The cogging torque of a novel dual-rotor axial field flux-switching permanent magnet (DRAFFSPM) machine is investigated in this paper. The analytical equation of the DRAFFSPM machine is deduced. Based on 3D finite element method, the influences of the design parameters on the cogging torque are analyzed. The H-shaped stator tooth with slot chamfer is proposed and the slot opening width and chamfer thickness are optimized to reduce the cogging torque. It shows that the cogging torque is the minimum when the stator tooth width and stator magnet width equal to 8o and 7.5o mech., respectively. The cogging torque can be reduced by ~64% when the rotor pole width is 1.6 times that of the original design. The cogging torque can be reduced by ~80% when the chamfer is added in the stator slot.

Torque ripple reduction of synchronous reluctance machines

2015 ◽  
Vol 34 (1) ◽  
pp. 3-17 ◽  
Author(s):  
K. Wang ◽  
Z.Q. Zhu ◽  
G. Ombach ◽  
M. Koch ◽  
S. Zhang ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Double Layer ◽  
Torque Ripple ◽  
Content Type ◽  
Synchronous Reluctance Machine ◽  
Barrier Layers ◽  
Reluctance Machine ◽  
Output Torque ◽  
Rotor Pole ◽  
Cage Induction Motor

Purpose – The purpose of this paper is to investigate the influence of stator and rotor pole number combinations together with the flux-barrier layers number on the performance of synchronous reluctance machine with emphasis on output torque capability and torque ripple. Design/methodology/approach – AC synchronous reluctance machine (SynRM) or permanent magnet assisted SynRM presently receives a great deal of interest, since there is less or even no rare-earth permanent magnet in the rotor. Most of SynRM machines employ a stator that is originally designed for a standard squirrel cage induction motor for a similar output rating and application, or the SynRM machine with 24-slot, four-pole are often directly chosen for investigation in most of the available literature. Therefore, it is necessary to investigate the influence of stator and rotor pole number combinations together with the flux-barrier layers number on the performance of SynRM machine with emphasis on output torque capability and torque ripple. Findings – The average torque decreases with the increase of the pole numbers but remain almost constant when employing different stator slot numbers but with the same pole number. In addition, the torque ripple decreases significantly with the increase of the stator slot number. The machine with double-layer flux-barrier in the rotor has the biggest average torque, while the machines with three- and four-layer flux-barrier in the rotor have almost the same average torque but their value is slightly smaller than that of machine with double-layer flux-barrier. However, the machine with three-layer flux-barrier has the lowest torque ripple but the highest torque ripple exists in the machine with double-layer flux-barrier. Research limitations/implications – The purely sinusoidal currents are applied in this analysis and the effects of harmonics in the current on torque ripple are not considered in this application. Originality/value – This paper has analyzed the torque ripple and average torque of SynRMs with considering slot/pole number combinations together with the flux-barrier number.

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