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The Study of Emerging Electrical Machine Technologies and Their Applications

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A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "F: Electrical Engineering".

Deadline for manuscript submissions: closed (28 February 2023) | Viewed by 29326

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Special Issue Editors

Prof. Dr. Rong-Jie Wang

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Guest Editor

Department of Electrical and Electronic Engineering, Stellenbosch University, Stellenbosch 7600, South Africa
Interests: special electrical machines; cooling design and analysis; electric traction and renewable energy systems

Prof. Dr. Maarten J. Kamper

E-Mail Website
Guest Editor

Department of Electrical Engineering, Stellenbosch University, Stellenbosch, South Africa
Interests: electrical machine design; electrical drives and control; renewable energy generator systems; electric vehicle propulsion
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

We kindly invite you to contribute an article to the Special Issue of the MDPI journal Energies on the topic “The Study of Emerging Electrical Machine Technologies and Their Applications.” The central theme of this Special Issue focuses on novel electrical machine technologies that have potential as next-generation electrical machines and their potential industry applications.

Topics of interest may include but are not limited to:

Novel permanent magnet (PM) machines;
Flux-modulated electrical machines ;
High-speed electrical machines;
Reluctance and PM-assisted synchronous machines;
Novel linear machines and applications;
Wound field machines for electric vehicles;
Novel induction machines;
Axial flux machines;
Permanent magnet or hybrid excited vernier machines;
Numerical techniques and optimization strategies.

We look forward to receiving your contributions. It is recommended to send a tentative title and a short summary of the manuscript to Energies Editor Ms. Carly Liu <[email protected]>.

Prof. Dr. Rong-Jie Wang
Prof. Dr. Maarten J. Kamper
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

electrical machines
permanent magnet machines
electrical traction motor drive
flux modulated machines
ship propulsion motor drive
wind power generation
stator permanent magnet machines
vernier machines
design optimization

Published Papers (12 papers)

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Research

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31 pages, 1492 KiB

Open AccessArticle

Development of a Transient Synchronization Analysis Tool for Line-Start PM Motors

by Phillip Schommarz and Rong-Jie Wang

Energies 2022, 15(23), 9206; https://doi.org/10.3390/en15239206 - 05 Dec 2022

Cited by 1 | Viewed by 1053

Abstract

With more stringent IEC energy efficiency standards, electrical machine industry increasingly focuses on new motor technologies. Amongst others, the line-start permanent magnet synchronous machine (LSPMSM) is considered as an attractive alternative to induction machine, especially for low power and fixed-speed applications. However, the design of LSPMSMs is rather complex as both steady-state and transient synchronization performances need to be considered. The synchronization capability determination of a LSPMSM design usually relies on time-consuming transient finite-element simulations, which is impractical for use in an iterative design optimization process. This paper compares and evaluates various existing analytical synchronization analysis methods in an attempt to identify most suitable equations and methods for fast synchronization analysis. Using the selected methods, a software tool is developed that can seamlessly work with ANSYS Electronics Desktop to perform rapid transient synchronization analysis. Given its ability to quickly determine the critical inertia factor of a LSPMSM design, the software tool is further adapted for use in a highly iterative, multi-objective design optimization procedure. It shows that the developed software tool can be successfully used in the design of LSPMSMs. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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15 pages, 10766 KiB

Open AccessArticle

Investigation of a Novel Consequent-Pole Flux-Intensifying Memory Machine

by Rui Tu, Hui Yang, Heyun Lin, Hanlin Zhan, Di Wu, Minghu Yu, Liang Chen and Wenjie Chen

Energies 2022, 15(15), 5501; https://doi.org/10.3390/en15155501 - 29 Jul 2022

Viewed by 1131

Abstract

This paper mainly focuses on the investigation and analysis of a novel consequent-pole flux-intensifying memory machine (CP-FIMM). The proposed CP-FIMM exhibits the advantages of a satisfactory flux-regulation range, reduction of the required magnetizing current magnitude, as well as similar torque with much less PM utilization compared to its conventional counterpart. By designing the q-axis flux barriers, the flux-intensifying structure can be realized to enhance the demagnetization withstand capability of the CP-FIMM. The machine topology and operating principle are described. Moreover, the equivalent magnetic circuit model is developed to highlight the performance improvement of the proposed CP-FIMM. Finally, the electromagnetic performance of the proposed CP-FIMM is compared with that of a benchmark conventional FIMM by 2-D and 3-D finite element analysis. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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26 pages, 13056 KiB

Open AccessArticle

Prospect of PM Vernier Machine for Wind Power Application

by Pushman Tlali and Rong-Jie Wang

Energies 2022, 15(13), 4912; https://doi.org/10.3390/en15134912 - 05 Jul 2022

Cited by 5 | Viewed by 1726

Abstract

This paper investigates the prospect of permanent magnet vernier machine (PMVM) technology for wind power applications. Two types of PMVMs are defined based on the winding arrangements and resultant gear ratio ranges. A comprehensive design study of the selected PMVM topologies is conducted at 1 and 3 MW power levels. The optimized candidate designs of the PMVMs are then evaluated and also compared against the equivalent permanent magnet synchronous machine (PMSM) in terms of performance, costs, size and mass. While the existing research publications mainly focused on the PMVM designs of (

G_{r} = 5

), this study reveals that the pole/slot combinations of PMVMs with (

G_{r} \leq 5

) are more appealing as there is a good trade-off between a reasonable power factor and high power density in these designs. It shows, in this paper, that the PMVM is a promising alternative to common PMSM technology for utility-scale wind-turbine drive-train applications. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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10 pages, 2350 KiB

Open AccessFeature PaperArticle

Semi-3D Analysis of a Permanent Magnet Synchronous Generator Considering Bolting and Overhang Structure

by Ji-Su Hong, Hoon-Ki Lee, Junghyo Nah, Kyong-Hwan Kim, Kyung-Hun Shin and Jang-Young Choi

Energies 2022, 15(12), 4374; https://doi.org/10.3390/en15124374 - 15 Jun 2022

Cited by 1 | Viewed by 4078

Abstract

This study deals with the characteristic analysis of a permanent magnet synchronous generator (PMSG) with a bolting and an overhang structure. Bolting is applied to a PMSG to prevent the defects caused by scattering. To compensate the flux reduction caused by the end effect and bolting material, an overhang structure is used for the permanent magnet machine. Therefore, an overhang structure must be considered in the three-dimensional (3D) analysis of a PMSG; however, such an analysis is time-intensive. To reduce the initial analysis time, we performed a semi-3D analysis of a PMSG considering a bolting and an overhang structure. Subsequently, we compared the output results of the characteristic analysis with a 3D finite element method and experimental results under loading. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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21 pages, 10616 KiB

Open AccessArticle

Novel Design of Six-Phase Spoke-Type Ferrite Permanent Magnet Motor for Electric Truck Application

by Hoyun Won, Yang-Ki Hong, Minyeong Choi, Jonathan Platt, Briana Bryant, Seungdeog Choi, Shuhui Li, Hwan-Sik Yoon, Timothy A. Haskew, Jongkook Lee, Taegyu Lee and Tae-Won Lim

Energies 2022, 15(6), 1997; https://doi.org/10.3390/en15061997 - 09 Mar 2022

Cited by 4 | Viewed by 3145

Abstract

This paper proposes a 300 kW 24-slot/10-pole 6-phase stator-shifted fractional-slot concentrated winding spoke-type ferrite permanent magnet machine for electric truck applications. The proposed motor consists of a stator with dual three-phase windings positioned 75 degrees apart to reduce higher-order MMF harmonic order, and a rotor with an inexpensive and high-resistance ferrite permanent magnet in the spoke configuration. The simulated result of the stator-shifted machine is compared with a fabricated stator-shifted machine, and the results show good agreement with each other. To further reduce the torque ripple from 2.5 to 0.9% while maintaining a high maximum torque of 2980 Nm, circular voids with a diameter of 11 mm are embedded in the rotor. The proposed motor is evaluated for irreversible demagnetization, mechanical and thermal stability, and fault tolerant ability. To assess the proposed motor performance, the electric truck simulation model is constructed using MATLAB/Simulink and used to compare with the reported 12-slot/10-pole rare-earth permanent magnet-based machine. Compared to a previously reported six-phase rare-earth permanent magnet based flat-type machine, the proposed motor can save 4.3 kWh of energy with a USD 2512 lower cost while retaining a similar motor performance. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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21 pages, 4185 KiB

Open AccessArticle

Evaluation of Drive Cycle-Based Traction Motor Design Strategies Using Gradient Optimisation

by Stavros Pastellides, Stiaan Gerber, Rong-Jie Wang and Maarten Kamper

Energies 2022, 15(3), 1095; https://doi.org/10.3390/en15031095 - 01 Feb 2022

Cited by 9 | Viewed by 2387

Abstract

In this paper, two design optimisation methods are evaluated using gradient-based optimisation for electric vehicle traction applications. A driving cycle-based approach is used to evaluate specific operational points for the design optimisation procedure. To determine the operational points, an energy centre of gravity (ECG) approach is used. Both optimisation methods are described, namely the point based method and the flux mapping method, with a focus on the flux mapping procedure. Within the flux mapping approach, an inner optimisation loop is defined in order to maintain the stability of gradient calculation for the gradient-based optimisation. An emphasis is placed on the importance of how the optimisation problem is defined, in terms of the objective function and constraints, and how it affects a gradient based optimisation. Based on a design case study conducted in the paper, it is found that the point-based strategy realised motor designs with a slightly lower overall cost (5.66% lower than that of the flux mapping strategy with 8 ECG points), whereas the flux mapping strategy found motor designs with a lower input energy (1.48% lower than that of the point-based strategy with 8 ECG points). This may be attributed to the difference in the definition and interpretation of constraints between these two methods. It is also shown that including more operational points from the driving cycle in the design optimisation leads to designs with reduced total input energy and thus better drive-cycle energy efficiency. This paper further illustrates the significant computational advantages of a gradient-based optimisation over a global optimisation method as it can be completed within a fraction of the time while still finding a global optimum, as long as the problem definition is correctly determined. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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17 pages, 3504 KiB

Open AccessArticle

Comparative Design and Performance Analysis of 10 kW Rare-Earth and Non-Rare Earth Flux Reversal Wind Generators

by Manne Bharathi, Udochukwu Bola Akuru and Malligunta Kiran Kumar

Energies 2022, 15(2), 636; https://doi.org/10.3390/en15020636 - 17 Jan 2022

Cited by 6 | Viewed by 1862

Abstract

Generators are a key technological element of the wind energy generation system. Currently, there is an increasing interest in adopting non-conventional stator-mounted permanent magnet generators, e.g., flux reversal generators (FRGs), which is a good alternative to conventional synchronous generators for medium-speed wind turbine generator applications. The usage of FRG with rare-earth (RE) permanent magnets (PMs) is increasing due to their high efficiency and high power density factors. However, RE PMs are unattractive to wind generators in terms of their cost and unpredictable market supply. In this paper, an attempt is made to study the potential of FRG with non-rare earths (ferrite PMs) for wind generators. The three-phase, 6/8 pole FRG is designed and compared with RE and NRE PMs for wind generator application at 375 r/min, 10 kW. Using 2D FEA, both the generators are compared in terms of their power generating performance with excellent overload capability. It shows that the average efficiency of the generators is approximately similar, but the torque density of NRE-FRG is only 51% that of RE-FRG. The NRE-FRG design is heavier, with the total active mass being 2.6 times higher than the RE-FRG, but with the estimated total active material cost of both generators almost the same. Moreover, the toque ripple for RE-FRG is 64% higher than for NRE-FRG. The demagnetization risk analysis was performed, and it is found that at higher temperatures, RE-FRG structures are prone to higher demagnetization risks, while it is much lower in NRE-FRGs. In summary, it is found that NRE-FRG is a suitable alternative to RE-FRG for medium-speed wind turbine generator applications in the 10-kW power range. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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13 pages, 5044 KiB

Open AccessCommunication

Optimal Design of a BLDC Motor Considering Three-Dimensional Structures Using the Response Surface Methodology

by Seong-Tae Jo, Hyo-Seob Shin, Young-Geun Lee, Ji-Hun Lee and Jang-Young Choi

Energies 2022, 15(2), 461; https://doi.org/10.3390/en15020461 - 10 Jan 2022

Cited by 11 | Viewed by 2958

Abstract

In this paper, the optimal design of a brushless direct current motor with a three-dimensional (3D) structure using the response surface methodology (RSM) is presented. There were two optimization goals: reduction of the cogging torque and maintenance of the back electromotive force to prevent performance degradation. For motors with a 3D structure, a 3D finite element method analysis is essential, though it requires considerable computation time. Therefore, to reduce the optimal design time, the 3D structure was placed on the 2D plane. Thereafter, a 2D corrected model was applied to the RSM. For the validity of the technique, the analysis results of the initial 3D model, 2D model, and 2D corrected model were compared, and the results of the optimal design 3D model, 2D corrected model, and experiment were compared. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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15 pages, 4073 KiB

Open AccessArticle

Characteristic Analysis and Experimental Verification of Electromagnetic and Vibration/Noise Aspects of Fractional-Slot Concentrated Winding IPMSMs of e-Bike

by Young-Geun Lee, Tae-Kyoung Bang, Jeong-In Lee, Jong-Hyeon Woo, Sung-Tae Jo and Jang-Young Choi

Energies 2022, 15(1), 238; https://doi.org/10.3390/en15010238 - 30 Dec 2021

Cited by 4 | Viewed by 2625

Abstract

In this study, we performed the electromagnetic and mechanical characteristic analyses of an 8-pole 12-slot interior permanent magnet synchronous motor (IPMSM). Permanent magnet synchronous motors are classified into surface permanent magnet synchronous motor and interior permanent magnet synchronous motors according to the type of rotor. The IPM type is advantageous for high-speed operation because of the structure where the permanent magnet is embedded inside the rotor, and it has the advantage of having a high output density by generating not only the magnetic torque of the permanent magnet, but also the reluctance torque. However, such a motor has more vibration/noise sources than other types, owing to changes in reluctance. The sources of motor noise/vibration can be broadly classified into electromagnetic, mechanical, and aerodynamic sources. Electromagnetic noise sources are classified into electromagnetic excitation sources, torque pulsations, and unbalanced magnetic forces (UMFs). Vibration and noise cause machine malfunctions and affect the entire system. Therefore, it is important to analyze the electromagnetic vibration source. In this study, the electromagnetic characteristics of an IPMSM were analyzed through the finite element method to derive the UMF. Vibration and noise analyses were performed by electromagnetic–mechanical coupling analysis, and vibration and noise characteristics based on electromagnetic noise sources were analyzed. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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17 pages, 44678 KiB

Open AccessArticle

Performance Evaluation of Harmonic Reduced Non-Overlap Winding Wound Rotor Synchronous Machine

by Karen S. Garner, Maarten J. Kamper and Andrew T. Loubser

Energies 2021, 14(22), 7501; https://doi.org/10.3390/en14227501 - 10 Nov 2021

Cited by 5 | Viewed by 1498

Abstract

The analysis and performance evaluation of a harmonic reduction strategy of a non-overlap winding wound rotor synchronous machine is conducted in this paper. The harmonic reduction strategy utilizes phase-shifts between coil currents to reduce sub- and higher-order harmonics. The design is performed on a 3 MW wound rotor synchronous machine with a 16/18 pole/slot combination. The application results in a lowered torque ripple and an increased efficiency of the designed machine. The manufacturing and testing of a 3 kW prototype to ascertain the effectiveness of the design is also presented. The practical measurements correlate successfully with the theoretical results. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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Review

Jump to: Research

21 pages, 7367 KiB

Open AccessReview

Sensorless Control of Dual Three-Phase Permanent Magnet Synchronous Machines—A Review

by Vahid Teymoori, Maarten Kamper, Rong-Jie Wang and Ralph Kennel

Energies 2023, 16(3), 1326; https://doi.org/10.3390/en16031326 - 27 Jan 2023

Cited by 7 | Viewed by 2287

Abstract

This paper presents an overview of various sensorless control methods, with a focus on dual three-phase permanent magnet synchronous machines (DTP-PMSM). Owing to the important role that DTP-PMSMs play in motion-control applications in industry, most academic researchers and industry activists seek to reduce costs and size while increasing the capability and efficiency of motion applications. This has led to an increase in the number of publications about multiphase machines in recent years. The purpose of this article is to review the most important sensorless control techniques, which are divided into two main categories, namely saliency-based control method for low-speed range and model-based control method for high-speed range. Both methods are subdivided into other categories, with a focus on DTP-PMSMs. The methods are compared with each other for the purpose of selecting the most suitable control technique for implementation in applications such as ship propulsion, wind turbines, and aerospace. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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19 pages, 2127 KiB

Open AccessReview

A Review of the Advancements in the Design of Brushless Doubly Fed Machines

by Oreoluwa I. Olubamiwa and Nkosinathi Gule

Energies 2022, 15(3), 725; https://doi.org/10.3390/en15030725 - 19 Jan 2022

Cited by 9 | Viewed by 1929

Abstract

Research interest on brushless doubly fed induction machines (BDFMs) is increasing, as they offer higher reliability compared to doubly fed induction generators (DFIGs) in wind turbines. At the moment, BDFMs do not have a definitive structure nor design process, as literature is rife with different approaches to designing BDFMs. In this paper, a comprehensive review of the design of BDFMs from available literature is conducted. The evolution of cascade induction machine systems to contemporary BDFMs is first illustrated. Pioneering research work in the evolution which have influences on modern BDFM designs are highlighted. Relevant research on different aspects of present day BDFM design are then discussed. BDFM design and optimization methodologies applied in available literature are also explored. Full article

(This article belongs to the Special Issue The Study of Emerging Electrical Machine Technologies and Their Applications)

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