Comparative Study of Dual PM Vernier Machines

In this paper, two types of dual permanent magnet (PM) machines, i.e., stator slot dual-PM (SSDPM) machine and split-tooth dual-PM (STDPM) machine, are investigated and compared. Both machines have consequent pole structure with Halbach array PMs. Their difference lies in the position of stator PM. The SSDPM machine has Halbach array PMs in the stator slots, while the STDPM machine has PMs between the split teeth. Torque characteristics, i.e., average torques and torque ripples, of different slot/pole number combinations of the two machines are compared. The 24 stator slots/20 rotor slots/4 armature pole pair (24S20R4Pa) SSDPM machine with distributed windings and the 24 stator slots/10 rotor slots/4 armature pole pair (12S20R4Pa) STDPM machine with concentrated windings are compared under both open-circuit and on-load conditions. The results show that the SSDPM machine is more competitive by delivering higher torque density and higher power density.

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Partitioned stator flux reversal machines having Halbach array PMs

COMPEL The International Journal for Computation and Mathematics in Electrical and Electronic Engineering ◽

10.1108/compel-12-2015-0442 ◽

2016 ◽

Vol 35 (2) ◽

pp. 396-406 ◽

Cited By ~ 1

Author(s):

M. Zheng ◽

Z.Z. Wu ◽

Z.Q. Zhu

Keyword(s):

Torque Ripple ◽

Open Circuit ◽

Fe Method ◽

Content Type ◽

Torque Density ◽

Flux Reversal ◽

Halbach Array ◽

Stator Flux ◽

Electromagnetic Performance ◽

Good Agreement

Purpose – In this paper, the partitioned stator flux reversal permanent magnet (PM) (PS-FRPM) machines with Halbach array PMs are investigated to compare with the machine having the conventional parallel magnetized PMs, and conventional FRPM machine. This paper aims to discuss these issues. Design/methodology/approach – The Halbach array PM machines with 2-, 3-, and 4-segment and ideal Halbach array PMs have similar topology and designed based on the PS-FRPM with parallel magnetized PMs. The open circuit analysis and electromagnetic performance has been calculated and compares with the aid of finite element (FE) method, and validated by experiments. Findings – The PS-FRPMs with Halbach array PMs have higher back-EMF and torque performance, as well as lower cogging torque and torque ripple, all having significantly higher torque density than the FRPM machine with single stator. The experimental results and FE predicted results of the 2-segment Halbach PM prototype machine are compared and good agreement is achieved. Originality/value – This paper introduces the new concept and design of PS-FRPMs having Halbach array PMs with different PM segments and idea PM array. The comparison with conventional FRPM and PS-FRPM with parallel magnetized PMs shows the benefits with PS-FRPMs with Halbach array PMs.

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Adaline-Based Control Schemes for Non-Sinusoidal Multiphase Drives—Part II: Torque Optimization for Faulty Mode

Energies ◽

10.3390/en15010249 ◽

2021 ◽

Vol 15 (1) ◽

pp. 249

Author(s):

Duc Tan Vu ◽

Ngac Ky Nguyen ◽

Eric Semail ◽

Hailong Wu

Keyword(s):

Harmonic Distortion ◽

Experimental Tests ◽

Open Circuit ◽

Permanent Magnet Synchronous Machine ◽

Torque Density ◽

Control Scheme ◽

Control Schemes ◽

Demonstration Video ◽

Torque Ripples ◽

Copper Losses

Fault tolerance has been known as one of the main advantages of multiphase drives. When an open-circuit fault happens, smooth torque can be obtained without any additional hardware. However, a reconfiguration strategy is required to determine new reference currents. Despite advantages of non-sinusoidal electromotive forces (NS-EMFs) such as high torque density, multi-harmonics existing in NS-EMFs cause more challenges for control, especially under faulty conditions. Therefore, to guarantee high-quality vector control of multiphase drives with multi-harmonic NS-EMFs, this two-part study proposes control schemes using adaptive linear neurons (Adalines) to adaptively eliminate torque ripples. The proposed simple Adalines are efficient because of taking advantage of the knowledge of rotor position and of torque harmonic rank induced by the NS-EMFs. The control scheme using an Adaline for healthy mode was described in part I of this study. In this second part, the control scheme using another Adaline for an open-circuit operation, under the impacts of multi-harmonics in NS-EMFs, is proposed. Notably, smooth torque and similar copper losses in the remaining healthy phases can be obtained. Experimental tests are carried out on a seven-phase permanent magnet synchronous machine (PMSM) with a high total harmonic distortion (THD = 38%) of NS-EMFs. A demonstration video is provided with this paper.

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Design and Analysis of a Dual Airgap Radial Flux Permanent Magnet Vernier Machine with Yokeless Rotor

Energies ◽

10.3390/en14082311 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2311

Author(s):

Mudassir Raza Siddiqi ◽

Tanveer Yazdan ◽

Jun-Hyuk Im ◽

Muhammad Humza ◽

Jin Hur

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Permanent Magnet ◽

Flux Linkage ◽

Element Analysis ◽

Cogging Torque ◽

Torque Density ◽

Stator Windings ◽

Radial Flux ◽

Torque Ripples

This paper presents a novel topology of dual airgap radial flux permanent magnet vernier machine (PMVM) in order to obtain a higher torque per magnet volume and similar average torque compared to a conventional PMVM machine. The proposed machine contains two stators and a sandwiched yokeless rotor. The yokeless rotor helps to reduce the magnet volume by providing an effective flux linkage in the stator windings. This effective flux linkage improved the average torque of the proposed machine. The competitiveness of the proposed vernier machine was validated using 2D finite element analysis under the same machine volume as that of conventional vernier machine. Moreover, cogging torque, torque ripples, torque density, losses, and efficiency performances also favored the proposed topology.

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Design and Analysis of a Novel Axial-Radial Flux Permanent Magnet Machine with Halbach-Array Permanent Magnets

Energies ◽

10.3390/en14123639 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3639

Author(s):

Rundong Huang ◽

Chunhua Liu ◽

Zaixin Song ◽

Hang Zhao

Keyword(s):

Permanent Magnet ◽

Permanent Magnets ◽

Torque Ripple ◽

Axial Flux ◽

Element Analysis ◽

Torque Density ◽

Axial Forces ◽

Halbach Array ◽

Radial Flux ◽

High Torque

Electric machines with high torque density are needed in many applications, such as electric vehicles, electric robotics, electric ships, electric aircraft, etc. and they can avoid planetary gears thus reducing manufacturing costs. This paper presents a novel axial-radial flux permanent magnet (ARFPM) machine with high torque density. The proposed ARFPM machine integrates both axial-flux and radial-flux machine topologies in a compact space, which effectively improves the copper utilization of the machine. First, the radial rotor can balance the large axial forces on axial rotors and prevent them from deforming due to the forces. On the other hand, the machine adopts Halbach-array permanent magnets (PMs) on the rotors to suppress air-gap flux density harmonics. Also, the Halbach-array PMs can reduce the total attracted force on axial rotors. The operational principle of the ARFPM machine was investigated and analyzed. Then, 3D finite-element analysis (FEA) was conducted to show the merits of the ARFPM machine. Demonstration results with different parameters are compared to obtain an optimal structure. These indicated that the proposed ARFPM machine with Halbach-array PMs can achieve a more sinusoidal back electromotive force (EMF). In addition, a comparative analysis was conducted for the proposed ARFPM machine. The machine was compared with a conventional axial-flux permanent magnet (AFPM) machine and a radial-flux permanent magnet (RFPM) machine based on the same dimensions. This showed that the proposed ARFPM machine had the highest torque density and relatively small torque ripple.

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Comparative Study of Stator-Consequent-Pole Permanent Magnet Machines With Different Stator-Slot Configurations

IEEE Transactions on Magnetics ◽

10.1109/tmag.2019.2896602 ◽

2019 ◽

Vol 55 (7) ◽

pp. 1-8 ◽

Cited By ~ 4

Author(s):

Ya Li ◽

Hui Yang ◽

Heyun Lin ◽

Shukang Lyu ◽

Zhenbao Pan

Keyword(s):

Comparative Study ◽

Permanent Magnet ◽

Permanent Magnet Machines ◽

Consequent Pole

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Comparative Study Between C-Core/E-Core SFPMM with Consequent Pole SFPMM

2019 International Symposium on Recent Advances in Electrical Engineering (RAEE) ◽

10.1109/raee.2019.8886946 ◽

2019 ◽

Author(s):

Wasiq Ullah ◽

Faisal Khan ◽

Noman Ullah ◽

Muhammad Umair ◽

Bakhtiar Khan ◽

...

Keyword(s):

Comparative Study ◽

Consequent Pole

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Design Issues for Claw Pole Machines with Soft Magnetic Composite Cores

Energies ◽

10.3390/en11081998 ◽

2018 ◽

Vol 11 (8) ◽

pp. 1998 ◽

Cited By ~ 3

Author(s):

Chengcheng Liu ◽

Jiawei Lu ◽

Youhua Wang ◽

Gang Lei ◽

Jianguo Zhu ◽

...

Keyword(s):

Special Kind ◽

Magnetic Composite ◽

Design Issues ◽

Soft Magnetic ◽

Torque Density ◽

Soft Magnetic Composite ◽

Torque Coefficient ◽

3D Finite Element Method ◽

Consequent Pole ◽

Machine Analysis

By using global ring winding, the torque coefficient of the transverse flux machine (TFM) is proportional to its number of pole pairs, and thus the TFM possesses high torque density ability when compared with other electrical machines. As a special kind of TFM, the claw pole machine (CPM) can have more torque due to its special claw pole teeth. The manufacturing of CPM or TFM with silicon steels was very difficult in the past, and is a handicap for the progress of this kind of machine. Thanks to the advent of soft magnetic composite (SMC) materials, the manufacturing process of CPM has become more and more simple. More attention has been paid to this kind of technology, and some mass production CPMs with SMC cores have appeared. However, there are few works that discuss the key design issues for this kind of machine. In this paper, a small CPM with SMC is used as as a research benchmark. Various design methods that can be adopted to improve its performance have been studied, including unequal stator claw pole teeth, a skewing magnet design, consequent pole design, and etc. The 3D finite element method (FEM) is used for the machine analysis, and it is verified by the experimental results of a CPM with SMC cores.

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