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.

Design of external rotor switched flux memory machine with hybrid magnets

2016 ◽  
Vol 35 (2) ◽  
pp. 507-524 ◽  
Author(s):  
D. Wu ◽  
Z.Q. Zhu ◽  
X. Liu
Keyword(s):  
Optimal Choice ◽  
Direct Drive ◽  
Element Analysis ◽  
Content Type ◽  
Copper Loss ◽  
Design Considerations ◽  
Rotor Pole ◽  
Internal Rotor ◽  
External Rotor ◽  
Flux Weakening

Purpose – The purpose of this paper is to propose the design concepts of external rotor switched flux hybrid magnet memory machine (SFHMMM) to further increase the torque capability while keeping the merits of internal rotor SFHMMM, such as adjustable back-EMF, and good flux weakening performance, etc. Design/methodology/approach – The torque enhancing principle of external rotor SFHMMM, and the design considerations such as feasible stator and rotor pole numbers (Ns/Nr ) are discussed by equations. Then, the performances such as back-EMF, dq-axis inductances, torque and flux weakening performances are calculated and compared with the aid of finite element analysis software. Findings – The external rotor SFHMMMs have obviously larger torque capabilities compared with the internal rotor ones under the same copper loss and machine size. The main reason is that the external SFHMMs could fully utilize the inner space of stator, which offers higher slot area, larger split ratio and consequently the higher average torque. For the external rotor machines with larger rotor pole number Nr , the back-EMF adjust ratio as well as the maxim torque are better. However, leakage flux and losses also increase with Nr due to limited machine size and higher operation frequency. Considering torque capability and flux weakening performance (efficiency map), the external SFHMMM with Nr =2Ns +1, e.g. 6/13 Ns/Nr stator/rotor pole machine, is the optimal choice. Originality/value – This paper introduces the design concept and design considerations of external SFHMMM for the first time. The proposed machine could be a competent candidate for direct-drive electric vehicle applications.

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.

Analysis of a Tubular Linear Permanent Magnet Motor for Reciprocating Compressor Applications

2013 ◽  
Vol 448-453 ◽  
pp. 2114-2119 ◽  
Author(s):  
Izzeldin Idris Abdalla ◽  
Taib Ibrahim ◽  
Nursyarizal Mohd Nor
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Outer Radius ◽  
Design Parameters ◽  
Reciprocating Compressor ◽  
Permanent Magnet Motors ◽  
Permanent Magnet Motor ◽  
Element Analysis ◽  
Split Ratio ◽  
Single Coil

This paper describes a design optimization to achieve optimal performance of a two novel single-phase short-stroke tubular linear permanent magnet motors (TLPMMs) with rectangular and trapezoidal permanent magnets (PMs) structures. The motors equipped with a quasi-Halbach magnetized moving-magnet armature and slotted stator with a single-slot carrying a single coil. The motors have been developed for reciprocating compressor applications such as household refrigerators. It is observed that the TLPMM efficiency can be optimized with respect to the leading design parameters (dimensional ratios). Furthermore, the influence of mover back iron is investigated and the loss of the motor is computed. Finite element analysis (FEA) is employed for the optimization, and the optimal values of the ratio of the axial length of the radially magnetized magnets to the pole pitch as well as the ratio of the PMs outer radius-to-stator outer radius (split ratio), are identified.

Investigation of magnet segmentation techniques for eddy current losses reduction in permanent magnets electrical machines

2015 ◽  
Vol 34 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Belli Zoubida ◽  
Mohamed Rachid Mekideche
Keyword(s):  
Genetic Algorithm ◽  
Finite Elements ◽  
Eddy Current ◽  
Permanent Magnets ◽  
Skin Effect ◽  
Electrical Machines ◽  
Design Parameters ◽  
Finite Elements Analysis ◽  
Eddy Current Losses ◽  
Content Type

Purpose – Reducing eddy current losses in magnets of electrical machines can be obtained by means of several techniques. The magnet segmentation is the most popular one. It imposes the least restrictions on machine performances. This paper investigates the effectiveness of the magnet circumferential segmentation technique to reduce these undesirable losses. The full and partial magnet segmentation are both studied for a frequency range from few Hz to a dozen of kHz. To increase the efficiency of these techniques to reduce losses for any working frequency, an optimization strategy based on coupling of finite elements analysis and genetic algorithm is applied. The purpose of this paper is to define the parameters of the total and partial segmentation that can ensure the best reduction of eddy current losses. Design/methodology/approach – First, a model to analyze eddy current losses is presented. Second, the effectiveness of full and partial magnet circumferential segmentation to reduce eddy loss is studied for a range of frequencies from few Hz to a dozen of kHz. To achieve these purposes a 2-D finite element model is developed under MATLAB environment. In a third step of the work, an optimization process is applied to adjust the segmentation design parameters for best reduction of eddy current losses in case of surface mounted permanent magnets synchronous machine. Findings – In case of the skin effect operating, both full and partial magnet segmentations can lead to eddy current losses increases. Such deviations of magnet segmentation techniques can be avoided by an appropriate choice of their design parameters. Originality/value – Few works are dedicated to investigate partial magnet segmentation for eddy current losses reduction. This paper studied the effectiveness and behaviour of partial segmentation for different frequency ranges. To avoid eventual anomalies related to the skin effect an optimization process based on the association of the finite elements analysis to genetic algorithm method is adopted.

Finite-Element Analysis of the Magnetic Field in a Magnetic Gear Mechanism

2013 ◽  
Vol 479-480 ◽  
pp. 230-233
Author(s):  
Yi Chang Wu ◽  
Bo Syuan Jian
Keyword(s):  
Magnetic Field ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnets ◽  
Design Parameters ◽  
Element Analysis ◽  
Magnetostatic Field ◽  
Gear Mechanism ◽  
Magnetic Gear ◽  
The Magnetic Field

This paper presents finite-element analysis (FEA) of the magnetic field of a magnetic gear mechanism. An external type magnetic gear mechanism, which consists of two identical magnetic gears with sector-shaped permanent magnets, is introduced first. Then, the magnetostatic field distribution and transmitted torque of the magnetic gear mechanism are simulated by a commercial FEA package Ansoft/ Maxwell. Next, the effects of design parameters, including the air-gap length, the number of magnetic pole pairs, and the height of permanent magnets, on the maximum transmitted torque are discussed. The results of this work are beneficial to the design of magnetic gear mechanisms.

Sinusoidal PWM Techniques in Rotor Pole Segmentation to Reduce Permanent Magnet Synchronous Machine Torque Ripple

2020 ◽  
Author(s):  
Khristian M. de Andrade Jr ◽  
Hugo E. Santos ◽  
Wellington M. Vilela, ◽  
Geyverson T. de Paula
Keyword(s):  
Permanent Magnets ◽  
Torque Ripple ◽  
Synchronous Machine ◽  
Element Analysis ◽  
Cogging Torque ◽  
Torque Ripple Reduction ◽  
Rotor Poles ◽  
Rotor Pole ◽  
Ripple Reduction ◽  
Torque Ripples

Torque ripples can cause mechanical stress in electrical machines, among otherproblems. The present paper proposes three methods to reduce these ripples in the permanent magnets synchronous machine considering rotor poles design. These methods consist in segmenting the rotor poles, with width and distances between segments obtained by SPWM techniques. The modulating wave is a sinwave which has the same frequency as the air gap flux density fundamental harmonic. Method 1 contemplates the unipolar SPWM technique, whereas methods 1 and 2 used the bipolar SWPM technique. Furthermore, the equations used to predict the cogging torque behavior are presented and verified by means of a finite element analysis. The torque ripple reduction is achieved due to the elimination of back-electromotive force harmonics and the decrease in the cogging torque peak. Method 1 has proved to be the most effective, reducing the torque ripple by 51.38% and 76.61% for the 4-pole and 8-pole machines, respectively. In addition, the magnet volume utilized has been reduced by 22.55% for the 4-pole machine, but the average torque value has been reduced by 18.7%. It is worth mentioning that the proposed methods do not require skewing to reduce the torque ripple.

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.

Novel linear switched-flux PM machine with 9/10 primary/secondary pole number combination

2015 ◽  
Vol 34 (6) ◽  
pp. 1656-1672 ◽  
Author(s):  
Qinfen Lu ◽  
Yanxin Li ◽  
Yunyue Ye ◽  
J.T. Chen ◽  
Z.Q. Zhu
Keyword(s):  
Permanent Magnet ◽  
Thrust Force ◽  
Load Condition ◽  
Design Parameters ◽  
Force Density ◽  
Direct Drive ◽  
Low Thrust ◽  
Element Analysis ◽  
Content Type ◽  
Force Ripple

Purpose – Due to linear structure, linear switched flux permanent magnet machines (LSFPMMs) also may have odd pole primary, such as 9, 15, 21, etc., without unbalanced magnetic force in equivalent rotary machines. The paper aims to discuss these issues. Design/methodology/approach – In order to increase the thrust force density, the influence of some major design parameters, including split ratio, PM thickness, primary slot width and secondary pole width, are investigated by finite element analysis. For reducing the thrust force ripple under on-load condition, the end auxiliary teeth are adopted and their positions are also optimized. Findings – This novel 9/10 primary/secondary poles LSFPMM has high average thrust force and low thrust force ripple by optimization. The results demonstrate that the odd pole primary may be a good candidate for long-stroke linear direct drive application. Originality/value – A novel 9/10 primary/secondary poles linear switched flux permanent magnet machine is developed in this paper. The similar conclusions could be obtained for other LSFPMMs with odd pole primary.

Design and analysis of a hybrid-excited wound field synchronous machine with high reluctance torque utilization

2020 ◽  
Vol 64 (1-4) ◽  
pp. 931-939
Author(s):  
Wenping Chai ◽  
Byung-il Kwon
Keyword(s):  
Finite Element Analysis ◽  
Magnetic Flux ◽  
Permanent Magnets ◽  
Synchronous Machine ◽  
Operating Conditions ◽  
Current Phase ◽  
Flux Linkage ◽  
Element Analysis ◽  
Rotor Pole ◽  
Maximum Field

The paper proposes a hybrid-excited wound field synchronous machine (HE-WFSM), which can achieve high reluctance torque utilization. The key of the proposed HE-WFSM is that two permanent magnets (PMs) assist each rotor pole in forming an additional magnetic flux circle. It is opposite to the magnetic flux circle along the q-axis in the WFSM. The reduction of the q-axis flux can help to improve the saliency ratio and reluctance torque. Additionally, the asymmetrical flux linkage achieves a closest current phase angle between the maximum field torque and the maximum reluctance torque. To highlight the advantages of the proposed HE-WRSM, a general WFSM was adopted as the basic machine and analyzed under the same operating conditions. All performances of the basic machine and proposed HE-WFSM were predicted using finite element analysis (FEA) in Jmag-Designer. Finally, it was confirmed that the proposed HE-WRSM can achieve high reluctance torque utilization.

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