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 Performance Evaluation of a Permanent Magnet-Assisted Synchronous Reluctance Machine with Hybrid Magnets of Ferrite Magnets and Rare-earth PMs

2017 ◽  
Author(s):  
Xiping Liu ◽  
Ya Li ◽  
Zhangqi Liu
Keyword(s):  
Rare Earth ◽  
Permanent Magnet ◽  
Torque Ripple ◽  
Hybrid Magnet ◽  
Element Analysis ◽  
Cost Performance ◽  
Synchronous Reluctance Machine ◽  
Reluctance Machine ◽  
Output Torque ◽  
Loss Efficiency

In this paper, a novel permanent magnet-assisted synchronous reluctance machine (PMASynRM) with rare-earth PMs and ferrite magnets is proposed. The performance of PMASynRM is discussed with respected to the different magnet ratio of rare-earth PMs and ferrite magnets. Some characteristics including the flux density, output torque, cogging torque, output power, power factor, torque ripple, loss, efficiency, and demagnetization are calculated by 2-D finite element analysis (FEA). The analysis results show that the excellent performance can be obtained by using hybrid magnet of rare-earth PMs and ferrite magnets with the suitable magnet ratio, and provide some desirable cost-performance trade-off.

Optimal design of synchronous reluctance machine

2014 ◽  
Vol 33 (5) ◽  
pp. 1569-1586 ◽  
Author(s):  
Haiwei Cai ◽  
Bo Guan ◽  
Longya Xu ◽  
Woongchul Choi
Keyword(s):  
Rare Earth ◽  
Optimal Design ◽  
Permanent Magnet ◽  
Torque Ripple ◽  
Content Type ◽  
Synchronous Reluctance Machine ◽  
Reluctance Machine ◽  
Interior Permanent Magnet ◽  
Ipm Machine ◽  
Lower Torque

Purpose – The purpose of this paper is to present optimally designed synchronous reluctance machine (SynRM) to demonstrate the feasibility of eliminating the use of rare earth permanent magnet (PM) in electric machine for vehicle traction applications. Design/methodology/approach – A typical rare earth interior permanent magnet (IPM) machine is used as the benchmark to conduct the optimal design study. Based on the flux distribution, major changes are made to the rotor lamination design. Enhanced torque production and lower torque ripple are specifically targeted as the two main objectives of the proposed design approach. Findings – As a result, the optimally designed SynRM can achieve performance very close to that of the benchmark PM machine with a potential for further improvement. Originality/value – Discussions of IPM replacement by optimally designed SynRM in electrical and hybrid electrical vehicles are given in terms of performance and cost.

Analysis and design of a high power density permanent magnet-assisted synchronous reluctance machine with low-cost ferrite magnets for EVs/HEVs

2016 ◽  
Vol 35 (6) ◽  
pp. 1949-1964 ◽  
Author(s):  
Xiping Liu ◽  
Ya Li ◽  
Zhangqi Liu ◽  
Tao Ling ◽  
Zhenhua Luo
Keyword(s):  
Rare Earth ◽  
Permanent Magnet ◽  
Power Density ◽  
High Power ◽  
Low Cost ◽  
High Power Density ◽  
Content Type ◽  
Synchronous Reluctance Machine ◽  
Reluctance Machine ◽  
Rotor Structure

Purpose The purpose of this paper is to propose a permanent magnet-assisted synchronous reluctance machine (PMASynRM) using ferrite magnets with the same power density as rare-earth PM synchronous motors used in Toyota Prius 2010. Design/methodology/approach A novel rotor structure with rectangular PMs is discussed with respect to the demagnetization of ferrite magnets and mechanical strength. Some electromagnetic characteristics including torque, output power, loss and efficiency are calculated by 2D finite element analysis. Findings The results of the analysis show that a high power density and high efficiency for PMASynRM can be achieved using ferrite magnets. Originality/value This paper proposes a novel rotor structure of PMASynRM with low-cost ferrite magnets that achieves high power density as permanent machines with rare-earth PMs.

Comparative study on synchronous reluctance and PM machines

2016 ◽  
Vol 35 (2) ◽  
pp. 607-623 ◽  
Author(s):  
Shun Cai ◽  
Meng-Jia Jin ◽  
He Hao ◽  
Jian-Xin Shen
Keyword(s):  
Permanent Magnet ◽  
Power Factor ◽  
High Speed ◽  
High Performance ◽  
Permanent Magnets ◽  
Content Type ◽  
Synchronous Reluctance Machine ◽  
Advantages And Disadvantages ◽  
Reluctance Machine ◽  
The Poor

Purpose – The purpose of this paper is to comparatively study a synchronous reluctance machine (SynRM) and a permanent magnet assisted synchronous reluctance machine (PMASynRM) as alternatives of the interior permanent magnet synchronous machine (IPMSM), and to investigate the performance and conclude both advantages and disadvantages. Design/methodology/approach – A unified mathematical model is established for the IPMSM, SynRM and PMASynRM. Then finite element method (FEM) is used to compare the electromagnetic performance. Permeability-frozen method is utilized to distinguish basic electromagnetic torque and reluctance torque. Findings – The PMASynRM can improve the power factor of the SynRM, overcome the drawback of the IPMSM in the high-speed flux-weakening region and is more proper to operate over a wide speed region. The SynRM is mechanically robust for lacking of the permanent magnets, and the PMASynRM can keep similar rotor stress as the SynRM by optimizing the magnets. Assembly of the SynRM is the simplest, and the economic performance of the SynRM and PMASynRM could be much better than the IPMSM which even uses ferrite magnets. Practical/implications – The SynRM can produce identical torque and efficiency compared with the IPMSM except the poor power factor. The poor power factor could be improved by adopting the PMASynRM, which is proved to be able to act as an alternative of the IPMSM for low-cost high-performance application. Originality/value – This paper provides the theoretical model of the IPMSM, SynRM and PMASynRM in a unified format. The electromagnetic, mechanical and economic performances of the three kinds of synchronous motors are compared comprehensively. Then, both the advantages and disadvantages are summarized.

scholarly journals On the Optimal Selection of Flux Barrier Reconfiguration for a Five-Phase Permanent Magnet Assisted Synchronous Reluctance Machine for Low-Torque Ripple Application

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Hamidreza Ghorbani ◽  
Mohammadreza Moradian ◽  
Mohamed Benbouzid
Keyword(s):  
Permanent Magnet ◽  
High Speed ◽  
Copper Wire ◽  
Implementation Process ◽  
Torque Ripple ◽  
Lumped Parameter Model ◽  
Optimal Model ◽  
Synchronous Reluctance Machine ◽  
Reluctance Machine ◽  
Low Torque

This paper aims to investigate the reconfigurations of rotor flux barriers for a five-phase Permanent Magnet Assisted Synchronous Reluctance Machine (PMASynRM). To precisely study the performance of the proposed configurations, a conventional PMASynRM with double-layer flux barriers is included in the study. Since the novel rotor schemes consume the same amount of rare-earth magnets, steel sheet materials, and copper wire, resulting in no extra manufacturing costs, the optimal reconfiguration should be determined, providing developed electromagnetic characteristics. Thus, all the proposed models are designed and analyzed under the same condition. The Lumped Parameter Model (LPM) is exported to the Finite Element Method (FEM) for precise analysis to reach developed torque and lower values of torque ripple. Based on the FEM results the model presenting the lowest torque fluctuations is selected as the optimal model and dynamically investigated. According to the results, in comparison with the conventional model, the introduced rotor designs provide a much lower value of torque fluctuations with a desirable amount of electromagnetic torque and power. In addition, the optimal model presents high values of power factor and efficiency, making it a vital alternative for low-torque ripple high-speed operations with no extra cost to the implementation process.

Torque ripple reduction of synchronous reluctance machines: using asymmetric flux-barrier

2015 ◽  
Vol 34 (1) ◽  
pp. 18-31 ◽  
Author(s):  
K. Wang ◽  
Z.Q. Zhu ◽  
G. Ombach ◽  
M. Koch ◽  
S. Zhang ◽  
...  
Keyword(s):  
Single Layer ◽  
Torque Ripple ◽  
Fe Method ◽  
Content Type ◽  
Synchronous Reluctance Machine ◽  
Reluctance Machine ◽  
Torque Ripple Reduction ◽  
Ripple Reduction ◽  
The Difference ◽  
The Impact

Purpose – The purpose of this paper is to reduce the torque ripple but not to decrease the average torque of synchronous reluctance machines by using one step or more than two axially laminated rotors with asymmetric flux-barrier. Design/methodology/approach – A 24-slot four-pole synchronous reluctance machine with overlapping windings and asymmetric flux-barrier in the rotor is, first, described and designed by finite element (FE) method for maximizing average torque. The dimensions of asymmetric flux-barrier including the pole span angle and flux-barrier angle will be optimized to minimize the torque ripple and its influence on the average torque is also investigated by FE analysis. The impact of current angle on the average torque and torque ripple are also analysed. The step laminations together with the asymmetric flux-barrier are employed for further torque ripple reduction which can consider the both rotation directions. Findings – The torque ripple of synchronous reluctance machine can be significantly reduced by employing asymmetric flux-barrier but the average torque is not reduced. 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. The 24-slot/four-pole synchronous reluctance machine with single-layer flux-barrier has been employed in this analysis, but this work can be continued to investigate the synchronous reluctance machine with multilayer flux-barrier. This asymmetric flux-barrier can be easily applied to permanent magnet (PM)-assisted synchronous reluctance machine and the interior PM machine with flux-barrier in the rotor, since the space which is used for PM insertion is the same as the SynRM machines. Originality/value – This paper has analysed the torque ripple and average torque of synchronous reluctance machines with asymmetric flux-barrier and step laminations with asymmetric flux-barrier. The torque ripple can be reduced by this flux-barrier arrangement. The difference of this technique with the other techniques such as stator/rotor skew is that the average torque can be improved.

scholarly journals A New Design Procedure for Rotor Laminations of Synchronous Reluctance Machines with Fluid Shaped Barriers

Electronics ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Federica Uberti ◽  
Lucia Frosini ◽  
Loránd Szabó
Keyword(s):  
Finite Element ◽  
Design Procedure ◽  
Optimization Procedure ◽  
Torque Ripple ◽  
Stator Winding ◽  
Post Processing ◽  
Processing Stage ◽  
Synchronous Reluctance Machine ◽  
Design And Optimization ◽  
Reluctance Machine

A new procedure for the design and optimization of the rotor laminations of a synchronous reluctance machine is presented in this paper. The configuration of the laminations is symmetrical and contains fluid-shaped barriers. The parametrization principle is used, which executes variations in the lamination geometry by changing the position, thickness and shape of the flux barriers. Hence, the optimization procedure analyzes the various configurations through finite element simulations, by means of the communication between MATLAB and Flux 2D. In the post processing stage, the best geometry which optimizes mean torque, torque ripple, efficiency and power factor is selected. Once the best rotor configuration is defined, further investigations allow improving its performance by modifying the current angle, the stator winding and the thickness of the radial ribs.

Sign in / Sign up

Export Citation Format

Share Document