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 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.

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.

scholarly journals Torque characteristics of double-stator permanent magnet synchronous machines

2017 ◽  
Vol 66 (4) ◽  
pp. 815-828
Author(s):  
Chukwuemeka Chijioke Awah ◽  
Ogbonnaya Inya Okoro
Keyword(s):  
Comparative Study ◽  
Permanent Magnet ◽  
Magnetic Force ◽  
Fault Tolerant ◽  
Synchronous Machine ◽  
Synchronous Machines ◽  
Permanent Magnet Synchronous Machines ◽  
Rotor Position ◽  
Rotor Pole ◽  
Static Torque

Abstract The torque profile of a double-stator permanent magnet (PM) synchronous machine of 90 mm stator diameter having different rotor pole numbers as well as dual excitation is investigated in this paper. The analysis includes a comparative study of the machine’s torque and power-speed curves, static torque and inductance characteristics, losses and unbalanced magnetic force. The most promising flux-weakening potential is revealed in 13- and 7-rotor pole machines. Moreover, the machines having different rotor/stator (Nr/Ns) pole combinations of the form Nr = Ns ± 1 have balanced and symmetric static torque waveforms variation with the rotor position in contrast to the machines having Nr = Ns ± 2. Further, the inductance results of the analyzed machines reveal that the machines with odd rotor pole numbers have better fault-tolerant capability than their even rotor pole equivalents. A prototype of the developed double-stator machine having a 13-pole rotor is manufactured and tested for verification.

scholarly journals Performances analysis of interior permanent magnet motors having different rotor iron pole shapes

2021 ◽  
Vol 12 (4) ◽  
pp. 1999
Author(s):  
Ahlam Luaibi Shuraiji ◽  
Buraq Abdulhadi Awad
Keyword(s):  
Permanent Magnet ◽  
Torque Ripple ◽  
High Energy ◽  
Electromagnetic Torque ◽  
Permanent Magnet Motors ◽  
Element Analysis ◽  
Magnet Material ◽  
Interior Permanent Magnet ◽  
Rotor Pole ◽  
Permanent Magnet Material

<p><span lang="EN-US">Interior permanent magnet motors (IPMMs) have been increasing in popularity, since the emergence of permanent magnet material with high energy products, i.e. rare earth permanent magnet material. This paper analyses the performances of IPMMs having different rotor iron pole shapes including eccentric, sinusoidal and sinusoidal with 3th order harmonic injected rotor pole arc shapes IPMMs. Cogging torque, static torque, torque ripple, torque-speed and power-speed curves of the mentioned motors have been compared. It must be noted that the mentioned motors have been designed with the same stator, PM shape and the same dimensions, in order to highlight the effect of the rotor pole arc shape on the performance of the such motors. Two-dimensional (2D) finite element analysis (FEA) has been utilized to design and analyze the mentioned machines. It has been found that rotor iron pole shape of the IPM has notably influence on the machine performance, practically on output electromagnetic torque and its ripple. The highest value of average electromagnetic torque as well as torque capability in the constant torque reign is delivered by 3th order harmonic injected rotor pole arc shapes machine, while the lowest torque ripple is obtained by the sinusoidal rotor pole arc machine.</span></p>

scholarly journals Direct Torque Control of Dual Three-Phase Permanent Magnet Synchronous Motor

2021 ◽  
Vol 297 ◽  
pp. 01017
Author(s):  
Fouad Labchir ◽  
Mhammed Hasoun ◽  
Aziz El Afia ◽  
Karim Benkirane ◽  
Mohamed Khafallah
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Direct Torque Control ◽  
Torque Ripple ◽  
Synchronous Motor ◽  
Torque Control ◽  
Stator Windings ◽  
Torque Control Strategy ◽  
Three Phase ◽  
Low Torque

In this paper a direct torque control strategy for dual three-phase permanent magnet synchronous motor (DTP-PMSM) is presented, the machine has two sets of three-phase stator windings spatially phase shifted by 30 electric degrees. In order to reduce the stator harmonic current, torque and flux are controlled based on regulators and Vector Space Decomposition technique. The proposed approach has the benefits of low stator current distortion and low torque ripple. The validity and the efficiency of the selected technique are confirmed by simulation results.

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.

scholarly journals Electromagnetic Torque Analysis of SRM 12/8 by Rotor/Stator Pole Angle

2021 ◽  
Vol 11 (3) ◽  
pp. 7187-7190
Author(s):  
D. B. Minh ◽  
L. D. Hai ◽  
T. L. Anh ◽  
V. D. Quoc
Keyword(s):  
Switched Reluctance Motor ◽  
Simulation Method ◽  
Torque Ripple ◽  
Ripple Effect ◽  
Switched Reluctance ◽  
Leakage Flux ◽  
Model And Simulation ◽  
Three Phase ◽  
Reluctance Motor ◽  
Rotor Pole

This paper presents the harmonic torque reduction by the different rotor pole angles of a three-phase 12/8 switched reluctance motor via an analytical model and simulation method. Improving torque performance by stator and rotor angles was applied for three-phase switched reluctance motor at stator pole/rotor pole ratios of 6/4, 8/12, 18/12, and 24/18. The average torque and the torque ripple effect by stator and rotor pole embrace have been recently studied in many projects. Due to the fact that leakage flux, flux density, and inductance are affected by the stator and rotor pole angles non-linear and linear leakage flux curves occur. Many stator and rotor pole angle combinations for the three-phase switched reluctance motor have already been done via a finite element method. In this paper, turn-on and turn-off angles will be figured based on stator and rotor pole embraces.

scholarly journals Static Eccentricity Fault Recognition in Three-Phase Line Start Permanent Magnet Synchronous Motor Using Finite Element Method

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mahdi Karami ◽  
Norman Mariun ◽  
Mohammad Rezazadeh Mehrjou ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Norhisam Misron ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Current Signal ◽  
Stator Current ◽  
Three Phase ◽  
Static Eccentricity ◽  
Element Method

This paper is dedicated to investigating static eccentricity in a three-phase LSPMSM. The modeling of LSPMSM with static eccentricity between stator and rotor is developed using finite element method (FEM). The analytical expression for the permeance and flux components of nonuniform air-gap due to static eccentricity fault is discussed. Various indexes for static eccentricity detection using stator current signal of IM and permanent magnet synchronous motor (PMSM) are presented. Since LSPMSM is composed of a rotor which is a combination of these two motors, the ability of these features is evaluated for static eccentricity diagnosis in LSPMSM. The simulated stator current signal of LSPMSM in the presence of static eccentricity is analyzed in frequency domain using power spectral density (PSD). It is demonstrated that static eccentricity fault generates a series of low frequency harmonic components in the form of sidebands around the fundamental frequency. Moreover, the amplitudes of these components increase in proportion to the fault severity. According to the mentioned observations, an accurate frequency pattern is specified for static eccentricity detection in three-phase LSPMSM.

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