Special Issue "Permanent Magnet Electrical Machines"

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "Energy Fundamentals and Conversion".

Deadline for manuscript submissions: 28 August 2020.

Special Issue Editor

Prof. Dr. Lorand Szabo
Website
Guest Editor
Department of Electrical Machines and Drives, Technical University of Cluj-Napoca, 400114 Cluj-Napoca, 28, Memorandumului str. Romania
Interests: variable reluctance machines; fault tolerant electrical machines; linear and surface stepper motors; condition monitoring and diagnosis of electrical machines
Special Issues and Collections in MDPI journals

Special Issue Information

Dear Colleagues,

Permanent magnet electrical machines are an emerging type of electromechanical converter technology. They have high power/torque density and demonstrate high efficiency. There has been increased interest in such machines due to their potential for widespread applications, such as industrial applications and applications in electric/hybrid vehicles, electric aircrafts and ships, renewable power generation, unmanned propulsion systems, etc.

The topic is broad, because it covers not only well-known surface and interior permanent magnet synchronous motors, brushless d.c. motors, hybrid steppers, etc., but also a lot of other electrical machines, such as those with hybrid excitation, double saliency, transverse flux, memory and magnetic-gearing types, vernier machines, etc. The subject includes both rotating and linear machines, those with interior and exterior rotors, and those having radial and axial flux.

Papers covering new topologies, structures, manufacturing technologies, analysis methods, control strategies, and new emerging applications of permanent magnet electrical machines are strongly welcome. Contributions dealing with advancements made in permanent magnet materials for electrical machines are also of interest.

Prof. Lorand Szabo
Guest Editor

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 papers will be 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 1800 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

  • brushless d.c. motors
  • double salient permanent magnet machines
  • flux reversal machines
  • flux switching machines
  • hybrid excitation machines
  • hybrid steppers
  • magnetic gearing
  • memory motors
  • permanent magnet-assisted claw-pole generator
  • permanent magnet-assisted variable reluctance machines
  • permanent magnet linear motors
  • permanent magnet synchronous machines
  • transverse flux machines
  • vernier machines

Published Papers (8 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Open AccessArticle
Voltage Harmonic Impacts on Electric Motors: A Comparison between IE2, IE3 and IE4 Induction Motor Classes
Energies 2020, 13(13), 3333; https://doi.org/10.3390/en13133333 - 30 Jun 2020
Abstract
Global energy systems are undergoing a transition process towards renewable energy and energy efficiency practices. Induction motors play an important role in this energy transformation process since they are widely used as industrial loads, representing more than 53% of global energy consumption. With [...] Read more.
Global energy systems are undergoing a transition process towards renewable energy and energy efficiency practices. Induction motors play an important role in this energy transformation process since they are widely used as industrial loads, representing more than 53% of global energy consumption. With more countries adopting minimum energy performance standards through more efficient induction motors, comparisons between these new technologies in the presence of electrical disturbances must be systematically evaluated before adopting a substitution policy in the industry. To this end, this work presents a comparative analysis of the impact of harmonic voltages on the performance and temperature rise of electric motors classes IE2, IE3 and IE4 in the same operational conditions in view of future substitutions. The results show that under ideal operating conditions the IE4 class permanent magnet motor has better performance in terms of consumption and temperature, however presenting non-linear characteristics. In the presence of voltage harmonics, this scenario changes completely according to the harmonic content. Finally, aiming to analyze the harmonics influence in the motor temperature rise a statistical analysis by means of Spearman correlation matrices is presented. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Graphical abstract

Open AccessArticle
Electromagnetic–Mechanical Coupling Optimization of an IPM Synchronous Machine with Multi Flux Barriers
Energies 2020, 13(7), 1819; https://doi.org/10.3390/en13071819 - 09 Apr 2020
Abstract
In this paper, an interior permanent magnet (IPM) synchronous machine with multiflux barriers is proposed to meet the wide speed regulation application requirements of electric vehicles. Based on the flux barrier characteristic, an electromagnetic–mechanical coupling optimization strategy is employed for the machine design. [...] Read more.
In this paper, an interior permanent magnet (IPM) synchronous machine with multiflux barriers is proposed to meet the wide speed regulation application requirements of electric vehicles. Based on the flux barrier characteristic, an electromagnetic–mechanical coupling optimization strategy is employed for the machine design. In order to facilitate the optimization design, the rotor barriers are divided into two optimization zones, the maximum stress zone and the maximum deformation zone. The electromagnetic–mechanical coupling optimization strategy is divided into two stages accordingly. In the first stage, the machine is regarded as a synchronous reluctance machine by ignoring permanent magnets, where the dimensions of the arc-shaped barriers are optimized to achieve a large reluctance torque and small stress. In the second stage, the dimensions of the arc-shaped PMs and the elliptical barrier are optimized with three objectives of minimum torque ripple, minimum flux linkage, and minimum deformation. After machine optimization, the comparison investigations are carried out on the basis of finite-element analysis by considering both the electromagnetic performances and mechanical performances. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Figure 1

Open AccessArticle
Tolerance-Insensitive Design of the Magnet Shape for a Surface Permanent Magnet Synchronous Motor
Energies 2020, 13(6), 1311; https://doi.org/10.3390/en13061311 - 11 Mar 2020
Abstract
Many studies have been conducted to reduce the cogging torque of electric power steering motors. However, in the mass production of such motors, it is essential to enhance performance robustness in relation to tolerances. For such motors, this work analyzes performance robustness in [...] Read more.
Many studies have been conducted to reduce the cogging torque of electric power steering motors. However, in the mass production of such motors, it is essential to enhance performance robustness in relation to tolerances. For such motors, this work analyzes performance robustness in relation to tolerances by applying a cycloid curve to the surface magnet of the rotor. Applying a cycloid curve to the magnet surface of the rotor is one of several ways to reduce cogging torque. To evaluate the performance of the cycloid curve, we compare it with an eccentric curve. The two curves are compared for the same specifications and evaluated using the indicator, tolerance insensitivity rate, which is used to assess performance robustness in relation to tolerances. The cycloid curve was evaluated to be more robust in relation to tolerances, as compared with the eccentric curve. Finally, an experiment was conducted to validate the robustness of the cycloid curve. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Figure 1

Open AccessArticle
DC-Link Current Control with Inverter Nonlinearity Compensation for Permanent Magnet Synchronous Motor Drives
Energies 2020, 13(3), 546; https://doi.org/10.3390/en13030546 - 22 Jan 2020
Abstract
For permanent magnet synchronous motors (PMSMs) supplied with a voltage source inverter, current control strategies are commonly implemented under the synchronously rotating reference frame. In order to simplify the system structure, three-phase currents can be measured with a single DC-link current sensor using [...] Read more.
For permanent magnet synchronous motors (PMSMs) supplied with a voltage source inverter, current control strategies are commonly implemented under the synchronously rotating reference frame. In order to simplify the system structure, three-phase currents can be measured with a single DC-link current sensor using the phase current reconstruction technique. However, it still needs to follow the conventional AC current control approach. In this paper, a DC-link current control method for PMSMs is proposed to further simplify the control system. The problem of phase current control was separated into the problems of amplitude control and phase control. Then, amplitude control was achieved using a closed-loop controller directly tracking the DC-link current; while phase control was achieved by AC-side pulse width modulation (PWM) following the phase angle of back electromotive force. The compensation for nonlinear distortion of the inverter was taken into account during the control process. Finally, the proposed method realized three-phase current control with a single current sensor and controller, and achieved the purpose of electromagnetic torque control. Experimental results demonstrate the effectiveness of the proposed method. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Graphical abstract

Open AccessArticle
Design and Analysis of a Permanent Magnet Synchronous Motor Considering Axial Asymmetric Position of Rotor to Stator
Energies 2019, 12(24), 4816; https://doi.org/10.3390/en12244816 - 17 Dec 2019
Abstract
This paper presents the design and analysis of a permanent magnet synchronous motor (PMSM) considering the axial asymmetric PM overhang for a smart actuator (SA) application such as an isokinetic exercise machine. This structure helps take advantage of the motor space effectively and [...] Read more.
This paper presents the design and analysis of a permanent magnet synchronous motor (PMSM) considering the axial asymmetric PM overhang for a smart actuator (SA) application such as an isokinetic exercise machine. This structure helps take advantage of the motor space effectively and makes the system small in size and light in weight. However, two drawbacks related to the performance of motor occur when the axial asymmetric PM overhang is used: (1) an axial attractive force (AAF) is created, which can produce motor noise and vibration; (2) the torque of motor is reduced compared with the symmetric PM overhang model. We used five steps to solve these problems. Firstly, the AAF according to the variation in axial position of the rotor to the stator was calculated and analyzed. Secondly, the torque was calculated under the same conditions to confirm that the system requirements were satisfied. The three-dimensional finite element analysis was used to determine the AAF and torque. Thirdly, the appropriate axial position of the rotor to the stator was suggested considering the analysis results and space inside the housing. Next, the commercial bearing type was chosen so that the total force acting on the bearing was below the bearing load limit to ensure motor stability. Finally, a prototype model was made and tested to confirm the accuracy of the analytical results. Through this study, by using the axial asymmetric PM overhang, the total length of SA was reduced by 5mm and the performance of motor was guaranteed. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Figure 1

Open AccessArticle
Study on Multi-DOF Actuator for Improving Power Density
Energies 2019, 12(21), 4204; https://doi.org/10.3390/en12214204 - 04 Nov 2019
Abstract
This study focuses on improving the power density of a spherical multi-degree-of-freedom (multi-DOF) actuator. A spherical multi-DOF actuator that can operate in three DOFs is designed. The actuator features a double air gap to reduce eddy current loss. However, a multi-DOF actuator driven [...] Read more.
This study focuses on improving the power density of a spherical multi-degree-of-freedom (multi-DOF) actuator. A spherical multi-DOF actuator that can operate in three DOFs is designed. The actuator features a double air gap to reduce eddy current loss. However, a multi-DOF actuator driven by a single actuator exhibits low power density. Therefore, a Halbach magnet array is applied to improve the power density of a spherical multi-DOF actuator, and its output characteristics are compared with those of an existing spherical multi-DOF actuator via finite element analysis. Additionally, the output characteristics are analyzed based on changes in the coil pitch angle and magneto-motive force of the rotating winding. Furthermore, it is necessary for a spherical multi-DOF actuator to move to the command position. Hence, a stability analysis is performed to ensure that the spherical multi-DOF actuator is stably driven based on the command position. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Graphical abstract

Open AccessArticle
Sensorless-MTPA Control of Permanent Magnet Synchronous Motor Based on an Adaptive Sliding Mode Observer
Energies 2019, 12(19), 3773; https://doi.org/10.3390/en12193773 - 03 Oct 2019
Cited by 1
Abstract
Different from the traditional method of the interior permanent magnet synchronous motor (IPMSM), the sensorless maximum torque per ampere (MTPA) control scheme in this paper does not need two observers for rotor position and d-q axis inductances, respectively. It only needs an adaptive [...] Read more.
Different from the traditional method of the interior permanent magnet synchronous motor (IPMSM), the sensorless maximum torque per ampere (MTPA) control scheme in this paper does not need two observers for rotor position and d-q axis inductances, respectively. It only needs an adaptive sliding mode observer (ASMO) based on the extended flux (EF) to realize double-loop control and MTPA operation simultaneously. The adaptive mechanism of rotor speed is designed to ensure stability of the ASMO. The rotor position and the difference between d-axis and q-axis inductances are obtained from the estimated EF to acquire the MTPA points when the position sensor of the IPMSM is absent. The proposed scheme is realized on a 20kW IPMSM where the sensorless control performance and the MTPA control performance are tested. The effectiveness of the proposed method is verified by the experiment results. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Graphical abstract

Open AccessArticle
Sliding-Mode-Observer-Based Open-Switch Diagnostic Method for Permanent Magnet Synchronous Motor Drive Connected with LC Filter
Energies 2019, 12(17), 3288; https://doi.org/10.3390/en12173288 - 26 Aug 2019
Cited by 1
Abstract
At present, pulse width modulation (PWM) technique is widely applied in motor drive systems. However, it may cause some unexpected effects: Bearing currents, overvoltage, power losses and unwanted noise. In some industrial cases, LC filters are always equipped in motor drive systems to [...] Read more.
At present, pulse width modulation (PWM) technique is widely applied in motor drive systems. However, it may cause some unexpected effects: Bearing currents, overvoltage, power losses and unwanted noise. In some industrial cases, LC filters are always equipped in motor drive systems to suppress those unexpected effects. In order to improve the reliability and safety of the drive system, fault diagnostic strategies for power switches should be utilized as other drive systems without LC filters. In the literature, some open-switch diagnostic approaches are based on the observers derived from the mathematical models. However, the models are changed by the LC filters. Therefore, the existing approaches, based on the observers are failed, due to the change of the models. This study proposes an open-switch diagnostic method for permanent magnet synchronous motor (PMSM) drive equipped with LC Filter. The novelty of the proposed method is that the model of the LC filter is considered. Therefore, open-switch faults can be detected and located in the drive systems with LC filters. The switching function model of the drive system is analyzed at first. Then a sliding mode observer (SMO) considering the model of the filter is proposed to estimate the filter voltages and other state variables. Consequently, the faults can be detected and located through the residual errors between the expected and estimated filter voltages. This approach features simplicity. Furthermore, any extra sensors are not necessary. Experimental results on a 750-W PMSM drive system with an LC filter proved the feasibility of the proposed method. Full article
(This article belongs to the Special Issue Permanent Magnet Electrical Machines)
Show Figures

Figure 1

Back to TopTop