Influence of end-effect on torque-speed characteristics of various switched flux permanent magnet machine topologies

2016 ◽  
Vol 35 (2) ◽  
pp. 525-539 ◽  
Author(s):  
M,M.J, Al-ani ◽  
Z.Q. Zhu
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
End Effect ◽  
Content Type ◽  
Constant Torque ◽  
Rotor Pole ◽  
Lower Torque ◽  
Power Capability ◽  
Electromagnetic Performance ◽  
Flux Leakage

Purpose – The purpose of this paper is to investigate and compare the influence of end-effect on the torque-speed characteristics of three conventional switched flux permanent magnet (SFPM) machines having different stator/rotor pole combinations, i.e. 12/10, 12/13 and 12/14 as well as three novel topologies with less permanent magnets (PMs), i.e. multi-tooth, E-core and C-core. Design/methodology/approach – SFPM machines combine the advantages of simple and robust rotor and easy management of the temperature due to the location of the PMs and armature windings on the stator. However, due to spoke location of the PMs a large flux leakage in the end region, i.e. end-effect, can be observed which could result in a large reduction in the electromagnetic performance. Therefore, the influence of end-effect on the torque-speed characteristics is investigated. 3D-finite element analyses (FEA) results are compared with their 2D-FEA counterparts in order to account for the end-effect influence. Findings – It has been concluded that due to end flux leakage, lower torque capability in the constant torque region is observed in the six machines. However, improved flux-weakening capability in the conventional machines can be exhibited at high current levels, whereas due to the large inductance lower power capability in the multi-tooth, E-core and C-core machines is obtained. Research limitations/implications – The influence of temperature rise on the performance is not included. Originality/value – This paper has analysed the influence of end-effect on the torque-speed characteristics of several SFPM machines.

scholarly journals Wind Micro-Turbine Networks for Urban Areas: Optimal Design and Power Scalability of Permanent Magnet Generators

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2759 ◽  
Author(s):  
Marco Palmieri ◽  
Salvatore Bozzella ◽  
Giuseppe Cascella ◽  
Marco Bronzini ◽  
Marco Torresi ◽  
...  
Keyword(s):  
Permanent Magnet ◽  
Urban Areas ◽  
Permanent Magnets ◽  
Design Procedure ◽  
Circuit Board ◽  
Small Scale ◽  
Electrical Machine ◽  
Direct Drive ◽  
Original Design ◽  
Power Capability

This work is focused on the design optimization of electrical machines that are used in small-scale direct-drive aerogenerators. A ducted wind turbine, equipped with a diffuser, is considered due to its enhanced power capability with respect to bare turbines. An annular type Permanent Magnet brushless generator is integrated in the turbine structure: the stator coils are placed in the internal part of the diffuser, whereas the permanent magnets are on an external ring connected to the turbine blade tips. Moreover, as regards the stator windings, the Printed Circuit Board (PCB) technology is investigated in order to exploit its advantages with respect to conventional wire coils, such as the increased current density capacity, the reduction of costs, and the enhanced precision and repeatability of the PCBs. An original design procedure is presented together with some scalability rules. An automated tool has been developed in order to aid the electrical machine designer in the first design stages: the tool performs multi-objective optimizations (using the Matlab Genetic Algorithm Toolbox), coupled to fast Finite Element analysis (through the open-source software FEMM) for the evaluation of the electromagnetic torque and field distribution. The proposed procedure is applied to the design of an annular PM generator directly coupled to a small-scale turbine for an urban application.

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.

Novel switched flux machine with radial and circumferential permanent magnets

2016 ◽  
Vol 35 (2) ◽  
pp. 473-492 ◽  
Author(s):  
M.M.J. Al-ani ◽  
Z.Q. Zhu
Keyword(s):  
Permanent Magnets ◽  
Outer Region ◽  
Optimization Procedure ◽  
Design Parameters ◽  
Element Analysis ◽  
Content Type ◽  
Copper Loss ◽  
Rotor Pole ◽  
Internal Rotor ◽  
External Rotor

Purpose – The paper purposes a novel SFPM machine topology with radial and circumferential permanent magnets (PMs). The paper aims to discuss this issue. Design/methodology/approach – In order to reduce the flux leakage in the stator-outer region and consequently achieve higher magnetic material utilization in switched flux permanent magnet (SFPM) machine, a novel topology with radial and circumferential PMs is proposed. This topology (SFRCPM) has the same structure as conventional SFPM (CSFPM) machine except of the additional set of radially magnetized PMs located around the back iron and surrounded by a laminated ring frame. Using finite element analysis (FEA) the influence of the design parameters on the performance is investigated in order to obtain an effective optimization procedure. Internal and external rotor SFRCPM machines with either NdFeB or ferrite magnets are investigated, optimized and compared with the CSFPM machine having the same size, copper loss and stator/rotor pole combination. Findings – It is concluded that comparing SFRCPM with its CSFPM machine counterpart, internal rotor SFRCPM machine can achieve high PM flux-linkage per magnet volume, however reduced slot area leads to low output torque, whereas external rotor SFRCPM machine can produce higher torque and torque per magnet volume. Originality/value – This paper proposes a novel SFPM machine topology.

Influence of the shape of squirrel-cage bars on the dimensions of permanent magnets in an optimized line-start permanent magnet synchronous motor

2017 ◽  
Vol 36 (1) ◽  
pp. 298-308 ◽  
Author(s):  
Łukasz Knypiński ◽  
Cezary Jedryczka ◽  
Andrzej Demenko
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Permanent Magnet Synchronous Motor ◽  
Particle Swarm ◽  
Additional Term ◽  
Electric Circuit ◽  
Pso Algorithm ◽  
Synchronous Motor ◽  
Particle Swarm Algorithm ◽  
Content Type

Purpose The purpose of this paper is to compare parameters and properties of optimal structures of a line-start permanent magnet synchronous motor (LSPMSM) for the cage winding of a different rotor bar shape. Design/methodology/approach The mathematical model of the considered motor includes the equation of the electromagnetic field, the electric circuit equations and equation of mechanical equilibrium. The numerical implementation is based on finite element method (FEM) and step-by-step algorithm. To improve the particle swarm optimization (PSO) algorithm convergence, the velocity equation in the classical PSO method is supplemented by an additional term. This term represents the location of the center of mass of the swarm. The modified particle swarm algorithm (PSO-MC) has been used in the optimization calculations. Findings The LSPMSM with drop type bars has better performance and synchronization parameters than motors with circular bars. It is also proved that the used modification of the classical PSO procedure ensures faster convergence for solving the problem of optimization LSPMSM. This modification is particularly useful when the field model of phenomena is used. Originality/value The authors noticed that to obtain the maximum power factor and efficiency of the LSPMSM, the designer should take into account dimensions and the placement of the magnets in the designing process. In the authors’ opinion, the equivalent circuit models can be used only at the preliminary stage of the designing of line-start permanent magnet motors.

A new optimal design of surface mounted permanent magnet synchronous motors with integral slot per pole

2018 ◽  
Vol 37 (1) ◽  
pp. 136-152
Author(s):  
Behrooz Rezaeealam ◽  
Farhad Rezaee-Alam
Keyword(s):  
Magnetic Field ◽  
Optimal Design ◽  
Permanent Magnet ◽  
Permanent Magnets ◽  
Air Gap ◽  
Permanent Magnet Synchronous Motors ◽  
Cogging Torque ◽  
Content Type ◽  
Synchronous Motors ◽  
Air Gap Magnetic Field

Purpose The purpose of this paper is to present a new optimal design for integral slot permanent magnet synchronous motors (PMSMs) to shape the air-gap magnetic field in sinusoidal and to reduce the cogging torque, simultaneously. Design/methodology/approach For obtaining this new optimal design, the influence of different magnetizations of permanent magnets (PMs), including radial, parallel and halbach magnetization is investigated on the performance of one typical PMSM by using the conformal mapping (CM) method. To reduce the cogging torque even more, the technique of slot opening shift is also implemented on the stator slots of analyzed PMSM without reduction in the main performance, including the air-gap magnetic field, the average torque and back-electromotive force (back-EMF). Findings Finally, an optimal configuration including the Hat-type magnet poles with halbach magnetization on the rotor and shifted slot openings on the stator is obtained through the CM method, which shows the main reduction in cogging torque and the harmonic content of air-gap magnetic field. Practical implications The obtained optimal design is completely practical and is validated by comparing with the corresponding results obtained through finite element method. Originality/value This paper presents a new optimal design for integral slot PMSMs, which can include different design considerations, such as the reduction of cogging torque and the total harmonic distortion of air-gap magnetic field by using the CM method.

Characterization of rotor losses in permanent magnet machines

2020 ◽  
Vol 39 (5) ◽  
pp. 1215-1226
Author(s):  
Antomne Caunes ◽  
Noureddine Takorabet ◽  
Sisuda Chaithongsuk ◽  
Laurent Duranton
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
High Speed ◽  
Permanent Magnets ◽  
Eddy Currents ◽  
Computing Time ◽  
Element Model ◽  
Permanent Magnet Machines ◽  
Content Type ◽  
Rotor Losses

Purpose The purpose of this paper is to present a synthesis of the analysis and modeling of the rotor losses in high speed permanent magnets motors. Design/methodology/approach Three types of losses are as a result of eddy currents in the conductive parts of the rotor. The analysis includes their characterization and the setup of a numerical model using finite element method. The adopted methodology is based on the separation of the losses which allows a better understanding of the physical phenomena. Each type of losses will be modeled and computed separately. Findings It is possible to make a precise estimate of the different losses in the rotor while keeping a relatively short computing time. Research limitations/implications The analysis is applied on a high-speed permanent magnet motor for avionic application. The model is validated with the commercial finite element model (FEM) software Flux2D. Originality/value The developed model allows an important save in terms of CPU-time compared to commercial FEM software while staying accurate. The separation of each losses and their sources is important for motor engineers and was requested for them to improve the designs more easily.

Temperature suppression of metal panel in electromagnetic field

Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 317-324
Author(s):  
Guochao Zheng ◽  
Fuli Wang ◽  
Baiping Yan ◽  
Runting Cheng
Keyword(s):  
Permanent Magnet ◽  
Magnetic Induction ◽  
Permanent Magnets ◽  
Magnetic Field Intensity ◽  
Metal Plate ◽  
Content Type ◽  
Magnetic Induction Intensity ◽  
Metal Panels ◽  
The Magnetic Field ◽  
Field Intensity Distribution

Purpose The purpose of this study is to suppress the temperature rise of high voltage wall bushing metal plate. Design/methodology/approach First, the authors built a model of a traditional metal plate and got the magnetic field intensity distribution by FEA tools. Optimized according to the magnetic field intensity distribution, the authors slot the traditional metal plate and embed permanent magnets in the slot. Finally, the authors got the temperature distribution diagrams of the above three cases at different current levels by FEA tools. Findings Slotted metal plate is beneficial to suppress magnetic induction intensity, but the improvement of the magnetic induction intensity uniformity is not obvious. The method of embedding a permanent magnet in a slotted metal plate can optimize the magnitude and uniformity of the magnetic induction intensity in the metal plate. The larger the current passing through the metal plate, the better the temperature suppression effect of the slotted metal plate and the slotted metal plate embedded in the permanent magnet. Originality/value The effect of structural factors, slotting plate and setting permanent magnets on slots on the temperature of supporting plate is studied. The paper proposes two methods, slotting metal panels and embedding permanent magnet metal panels, to solve the problems of eddy current loss and high calorific value of the panel, which is of great significance to the safety of the grid equipment.

Design and finite element analysis of modular C-Core stator tubular linear oscillating actuator for miniature compressor

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sumeet Khalid ◽  
Faisal Khan ◽  
Zahoor Ahmad ◽  
Basharat Ullah
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnets ◽  
Performance Comparison ◽  
Design Parameters ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Content Type ◽  
Static And Dynamic Analysis ◽  
Electromagnetic Performance

Purpose For compactness and ease in assembling, a novel miniature size tubular moving magnet linear oscillating actuator (MT-MMLOA) design for miniature linear compressor application is proposed in this paper. Design/methodology/approach This MT-MMLOA design possesses a modular C-core stator structure having separation at the middle. Axially magnetized tubular permanent magnets are accommodated on the mover. To improve the output parameters of the linear oscillating actuators (LOA), all the design parameters are optimized using a parametric sweep. Finite element analysis of the proposed design is performed to examine the magnetic flux density as well as thrust force under both static and dynamic analysis within the intended stroke range. Findings Compared to conventional LOA for miniature compressors, the motor constant of the proposed LOA is 37 N/A that is 85% greater while keeping the same size of LOA. Permanent magnet volume used in the investigated topology of LOA is 26% reduced. Additionally, the overall volume of the machine is 10.3% decreased. Furthermore, the proposed topology is simple, inexpensive and easy to manufacture. Originality/value Electromagnetic performance comparison with different topologies proposed earlier in literature is carried out to prove the performance superiority of the proposed design.

Influence of design parameters on inductances of e-core axial field flux-switching permanent magnet machines

2016 ◽  
Vol 35 (2) ◽  
pp. 493-506 ◽  
Author(s):  
Zhang Wei ◽  
Lin Ming Yao
Keyword(s):  
Permanent Magnet ◽  
Fault Tolerant ◽  
Short Circuit ◽  
Open Circuit ◽  
Design Parameters ◽  
Axial Field ◽  
Content Type ◽  
Copper Loss ◽  
Tooth Width ◽  
Rotor Pole

Purpose – Axial field flux-switching permanent magnet machine (AFFSPMM) can be applied in the field of electric and hybrid electric vehicles because of short axial size, large torque density, and high-power density. The purpose of this paper is to improve the reliability of AFFSPMM itself, the design parameters have to be considered for attaining high self-inductances and reduced mutual-inductances. Design/methodology/approach – The original parameters of E-core AFFSPMM are designed with reference to a 600 W prototype, on the basis of which the 3-D model of the original AFFSPMM is established, and the inductances are calculated by finite element method. The influence of these parameters on the inductances, including combinations of stator and rotor pole numbers, spilt ratio, stator side tooth width, magnet thickness, and rotor pole width etc., are respectively investigated and analyzed under the constant copper loss. Findings – The relationships of rotor pole numbers and inductances are deduced on the condition of the fixed stator poles. It is found that the rotor pole numbers has significant effects on the ratio of mutual-inductance to self-inductance, and the self-inductance is mainly affected by the rotor pole numbers, the split ratio, the stator tooth width, and the rotor pole width. The asymmetry of back-EMF can be largely reduced by optimizing the rotor tooth width. In this paper, the static characteristics are compared and analyzed for the original and optimal 6/14-pole AFFSPMM. Meanwhile, the open-circuit and short-circuit fault are investigated by transient analysis. The results show that the optimized E-core AFFSPMM has good fault tolerance. Originality/value – The research of inductance characteristics for E-core AFFSPMM is valuable to design the fault-tolerant machine, by which the cost of control and manufacture can be largely saved.

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