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18 pages, 11663 KB

Open AccessArticle

Design and Performance Characterization of the E-Core Outer-Rotor Hybrid-Excitation Flux Switching Machine

by Zhiyuan Xu and Ming Cheng

Energies 2025, 18(3), 629; https://doi.org/10.3390/en18030629 - 29 Jan 2025

Cited by 1 | Viewed by 1483

This paper proposes an E-core outer-rotor hybrid-excitation flux switching (OR-HEFS) machine for in-wheel direct driving application. According to the general air gap field modulation theory, the magneto-motive force (MMF) permeance model was established to investigate the air gap flux density, and then the [...] Read more.

This paper proposes an E-core outer-rotor hybrid-excitation flux switching (OR-HEFS) machine for in-wheel direct driving application. According to the general air gap field modulation theory, the magneto-motive force (MMF) permeance model was established to investigate the air gap flux density, and then the torque generation, the flux regulation principle, and the excitation-winding-induced voltage of the E-core OR-HEFS machine were analyzed. To characterize the output performances, the influence of the design parameters was investigated for the E-core OR-HEFS machine, including the split ratio, stator tooth arc, PM arc, fault-tolerant tooth arc, rotor tooth arc, stator yoke width and rotor yoke width. The performances contained the output torque, torque ripple, flux regulation ratio, and the excitation-winding-induced voltage. On this basis, the aforementioned four performances were optimized by means of the non-dominated sorting genetic algorithm II (NSGA-II). Based on the optimization result, a prototype was manufactured and tested to verify the whole investigation of this paper. Full article

(This article belongs to the Special Issue New Journey of Energy and Electric Vehicle Revolutions—Infinite Possibilities in the Science World: In Honor of Prof. Dr. C.C. Chan’s 90th Birthday)

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18 pages, 12466 KB

Open AccessArticle

Electromagnetic Vibration Analysis of Transverse Flux Permanent Magnet Linear Submersible Motor for Oil Production

by Mei Zhao, Yihao Li, Sicheng Zuo, Pingpeng Tang, Tong Yao, Huaqiang Zhang and Shunjie Wu

Energies 2023, 16(23), 7911; https://doi.org/10.3390/en16237911 - 4 Dec 2023

Cited by 1 | Viewed by 2050

Abstract

A transverse flux linear motor is a special type of linear motor with a high thrust force density, and it has broad application prospects in the field of linear direct-drive systems. In the process of oil production, the vibration of the linear motor [...] Read more.

A transverse flux linear motor is a special type of linear motor with a high thrust force density, and it has broad application prospects in the field of linear direct-drive systems. In the process of oil production, the vibration of the linear motor poses a significant amount of harm to the system due to its special slender structure. This paper focuses on the electromagnetic vibration of a transverse flux permanent magnet linear submersible motor (TFPMLSM). Firstly, the no-load air gap flux density is calculated based on the field modulation principle. Secondly, the radial electromagnetic force (REF) of the TFPMLSM is calculated, and the finite element method (FEM) is used to analyze the time-space and spectral characteristics of the REF. Then, the influence of secondary eccentricity on the frequency spectrum of the REF is further concluded. Finally, the natural frequencies of each vibration mode are calculated using the modal superposition method and the influence of the REF on the motor vibration is obtained through magnetic-structural coupling analysis. The research results found that the motor does not cause resonance at low speeds, and the fundamental frequency of REF has the greatest impact on electromagnetic vibration. Full article

(This article belongs to the Special Issue Analysis and Design of High-Energy-Efficiency Permanent Magnet Machines)

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15 pages, 5302 KB

Open AccessArticle

Improving Torque Analysis and Design Using the Air-Gap Field Modulation Principle for Permanent-Magnet Hub Machines

by Yuhua Sun, Nicola Bianchi, Jinghua Ji and Wenxiang Zhao

Energies 2023, 16(17), 6214; https://doi.org/10.3390/en16176214 - 27 Aug 2023

Cited by 4 | Viewed by 2892

Abstract

The Double Permanent Magnet Vernier (DPMV) machine is well known for its high torque density and magnet utilization ratio. This paper aims to investigate the torque generation mechanism and its improved design in DPMV machines for hub propulsion based on the field modulation [...] Read more.

The Double Permanent Magnet Vernier (DPMV) machine is well known for its high torque density and magnet utilization ratio. This paper aims to investigate the torque generation mechanism and its improved design in DPMV machines for hub propulsion based on the field modulation principle. Firstly, the topology of the proposed DPMV machine is introduced, and a commercial PM machine is used as a benchmark. Secondly, the rotor PM, stator PM, and armature magnetic fields are derived and analyzed considering the modulation effect, respectively. Meanwhile, the contribution of each harmonic to average torque is pointed out. It can be concluded that the 7th-, 12th-, 19th- and 24th-order flux density harmonics are the main source of average torque. Thanks to the multi-working harmonic characteristics, the average torque of DPMV machines has significantly increased by 31.8% compared to the counterpart commercial PM machine, while also reducing the PM weight by 75%. Thirdly, the auxiliary barrier structure and dual three-phase winding configuration are proposed from the perspective of optimizing the phase and amplitude of working harmonics, respectively. The improvements in average torque are 9.9% and 5.4%, correspondingly. Full article

(This article belongs to the Special Issue Modeling, Control and Diagnosis of Electrical Machines and Devices)

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17 pages, 15102 KB

Open AccessArticle

Research on High-Torque-Density Design for Axial Modular Flux-Reversal Permanent Magnet Machine

by Shan Lin, Lanchao Chang, Peng Su, Yongjian Li, Wei Hua and Yi Shen

Energies 2023, 16(4), 1691; https://doi.org/10.3390/en16041691 - 8 Feb 2023

Cited by 3 | Viewed by 2949

Abstract

The traditional flux reversal permanent magnet (FRPM) machine has high torque ripple due to the double salient-pole structure, and the effective air-gap length is increased by the permanent magnet structure of the stator tooth surface, which affects the size of the air-gap magnetomotive [...] Read more.

The traditional flux reversal permanent magnet (FRPM) machine has high torque ripple due to the double salient-pole structure, and the effective air-gap length is increased by the permanent magnet structure of the stator tooth surface, which affects the size of the air-gap magnetomotive force (MMF). This paper proposes an axial modular flux-reversal permanent magnet (AM-FRPM) machine with attractive torque capabilities. Based on air-gap magnetic field modulation theory, a method to achieve optimal air-gap harmonic torque contributions was developed. Then, the principle for high-torque-density generation in the AM-FRPM machine under an alternating magnetization topology was investigated using the PM magnetic field modulation and armature reaction magnetic field modulation. In addition, the cogging torque suppression mechanism, which guides the selection of stator-slot and rotor-pole combinations, was investigated. In addition, a comprehensive comparison of the electromagnetic characteristics of two AM-FRPM machines and a traditional FRPM machine was conducted. Then, the advantages and disadvantages of the three machines were analyzed. Finally, prototypes were manufactured and tested to verify the correctness of the theoretical analysis. Full article

(This article belongs to the Special Issue Analysis and Design of High-Energy-Efficiency Permanent Magnet Machines)

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14 pages, 7427 KB

Open AccessArticle

A New Dual Stator Permanent Magnet Machine Based on Field Modulation Theory

by Ziyang Ding, Chao He, Chunmei Feng and Jianfei Yang

Sustainability 2023, 15(1), 281; https://doi.org/10.3390/su15010281 - 24 Dec 2022

Cited by 4 | Viewed by 4158

Abstract

Increasing industrial development puts forward high requirements for the performances of stator permanent magnet (PM) machines, such as torque density and efficiency. The paper proposes a new dual stator PM machine based on field modulation theory (DSPMM), which employs the intermediate rotor participating [...] Read more.

Increasing industrial development puts forward high requirements for the performances of stator permanent magnet (PM) machines, such as torque density and efficiency. The paper proposes a new dual stator PM machine based on field modulation theory (DSPMM), which employs the intermediate rotor participating in the electromechanical energy conversion of the internal and external machine. The proposed machine has the advantages of high torque density and high efficiency and solves the problem of insufficient space utilization of a single stator machine. The evolution process and working principle of the proposed DSPMM are studied. The flux-switching-type PM (FSPM) and the flux-reversal-type PM (FRPM) are employed in the proposed DSPMM, which forms four representative machines. For a fair comparison, the proposed machines employ identical key parameters, i.e., PM volume, the outer radius of the outer stator, and active airgap length. Based on finite element analysis (FEA), the electromagnetic performances of the four representative DSPMM under no-load and rated load, and different copper consumption conditions are analyzed and compared. The calculated results show that the proposed DSPMM with inner FSPM stator and outer FRPM stator can provide high output torque, low torque ripple, high power factor, and high efficiency. Full article

(This article belongs to the Special Issue Intelligence and Sustainability in Electrical Engineering)

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13 pages, 16533 KB

Open AccessArticle

Analysis of DC Winding Induced Voltage in Wound-Rotor Synchronous Machines by Using the Air-Gap Field Modulation Principle

by Wentao Zhang, Ying Fan, Z. Q. Zhu, Zhongze Wu, Wei Hua and Ming Cheng

World Electr. Veh. J. 2022, 13(11), 215; https://doi.org/10.3390/wevj13110215 - 17 Nov 2022

Cited by 1 | Viewed by 5452

Abstract

In order to analyze the DC winding induced voltage in the wound-rotor synchronous machine, this paper uses the air-gap field modulation principle to investigate its operation mechanism and harmonic order. By establishing the analytical magneto-motive force (MMF)-permeance model, the DC winding induced voltage [...] Read more.

In order to analyze the DC winding induced voltage in the wound-rotor synchronous machine, this paper uses the air-gap field modulation principle to investigate its operation mechanism and harmonic order. By establishing the analytical magneto-motive force (MMF)-permeance model, the DC winding induced voltage per electrical cycle under open-circuit condition, armature reaction condition and on-load condition are deduced. Analytical analysis shows that the MMF function, stator and rotor permeance function are critical factors that influence the harmonic order of the DC winding induced voltage. The analysis results are compared with those predicted by the finite element analysis (FEA). Both non-linear steel and linear steel conditions are accounted in the FEA analysis, and the results show that the analytical deduction result agrees well with the FEA analysis result. Full article

(This article belongs to the Special Issue Recent Advances in Novel Permanent Magnet and Magnetless Machines and Control for Electric Vehicles)

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19 pages, 5763 KB

Open AccessArticle

Design and Analysis of Modulated Magnetic Pole for Dual Three-Phase Surface-Mounted Permanent Magnet Synchronous Motor

by Liyan Guo, Zhongyuan Hao, Jiaqi Xu, Huimin Wang, Xinmin Li and Shuang Wu

Energies 2022, 15(13), 4597; https://doi.org/10.3390/en15134597 - 23 Jun 2022

Cited by 5 | Viewed by 2656

Abstract

In order to improve the air-gap magnetic field waveform and reduce the torque ripple of dual three-phase surface-mounted permanent magnet synchronous motors (PMSMs), a new surface-mounted modulated permanent magnet (PM) structure is proposed in this paper. Compared with the existing pole-cutting structure, the [...] Read more.

In order to improve the air-gap magnetic field waveform and reduce the torque ripple of dual three-phase surface-mounted permanent magnet synchronous motors (PMSMs), a new surface-mounted modulated permanent magnet (PM) structure is proposed in this paper. Compared with the existing pole-cutting structure, the modulated magnetic pole does not need to customize the precise machining mold. However, when the modulation pole structure is installed, only the magnetic block-assisted assembly structure is designed to reduce the manufacturing cost. Based on the principle of specific harmonic elimination technology (SHET), the number, size and position angle of the modulated magnetic poles can be calculated, and the elimination or the injection of specific harmonics of the air-gap magnetic field can be realized, which can optimize the performance of the motor. It can be seen that the modulation pole structure based on SHET is also an effective method to improve the sinusoidal waveform of the air-gap magnetic field of the surface-mounted PM motor. Full article

(This article belongs to the Special Issue New Development of Power Electronic Converter Technology and Control Technology in Motor Systems)

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9 pages, 17908 KB

Open AccessArticle

Experimental Investigation on Floating Solar-Driven Membrane Distillation Desalination Modules

by Qingxiu Miao, Yaoling Zhang, Shuo Cong and Fei Guo

Membranes 2021, 11(5), 304; https://doi.org/10.3390/membranes11050304 - 21 Apr 2021

Cited by 10 | Viewed by 3737

Abstract

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven [...] Read more.

Membrane distillation (MD) processes need a relatively mild temperature gradient as the driving force for desalination. In the field, it is reasonable to utilize solar energy as the heat source for the feed, and seawater as the infinite cold source for condensation. Solar-driven MD provides a route for the practical application of seawater desalination at a small scale. In this work, we focus on floating MD modules with a solar heating bag as the power source, and perform proof-of-principle experiments on the MD performance under various conditioning parameters, including feed flow rate, feed temperature, salinity, air gap, and sea waves. The results indicate that floating solar-driven MD modules are feasible in terms of permeate flux and salt rejection ratio, and the upward evaporation MD configuration leads to a better performance in terms of permeate flux. The simulation and experiments also show that the natural sea waves disturb the heating bag and the MD module floating on the surface of seawater, and effectively enhance the feed circulation and transport in the system. Full article

(This article belongs to the Special Issue Developments in Innovative Membrane Desalination Processes)

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16 pages, 5069 KB

Open AccessFeature PaperArticle

A Novel DC-Coil-Free Hybrid-Excited Machine with Consequent-Pole PM Rotor

by Qingsong Wang and Shuangxia Niu

Energies 2018, 11(4), 700; https://doi.org/10.3390/en11040700 - 21 Mar 2018

Cited by 7 | Viewed by 3624

Abstract

This paper proposes a new DC coil free hybrid excited machine concept, which has no external field windings. The technical novelty is the integration of field windings and armature windings. DC bias current is injected into the excitation and the field windings in [...] Read more.

This paper proposes a new DC coil free hybrid excited machine concept, which has no external field windings. The technical novelty is the integration of field windings and armature windings. DC bias current is injected into the excitation and the field windings in the traditional hybrid excited machine are eliminated. Compared with traditional hybrid-excited machines with additional field windings, the proposed machine can realize a higher slot utilization ratio, hence achieve a higher torque density and a wider flux adjusting range. Another advantage of the proposed machine is that the voltage drop associated with flux regulation is small due to the small DC resistance, and the torque generating capability at the flux regulating region can be improved accordingly. The rotor is specifically designed with magnet-iron sequences and a consequent-pole, in which the permanent magnet and iron pole are alternatively employed. A bi-directional flux modulating effect can be achieved, which can contribute to the magnetic coupling in the air-gap. Analytical derivation is used to describe the operating principle, and the proposed machine was optimally designed using the Tabu search algorithm. A prototype was made, and its performances investigated through experimental tests. Full article

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17 pages, 2671 KB

Open AccessArticle

Influences of Winding MMF Harmonics on Torque Characteristics in Surface-Mounted Permanent Magnet Vernier Machines

by Daekyu Jang and Junghwan Chang

Energies 2017, 10(4), 580; https://doi.org/10.3390/en10040580 - 23 Apr 2017

Cited by 11 | Viewed by 6576

Abstract

This paper presents the influences of winding magneto-motive force (MMF) harmonics on the torque characteristics in surface-mounted permanent magnet vernier (SPMV) machines. Based on the magnetic gearing effects, the armature magnetic field of the SPMV machines is modulated by flux modulation poles (FMPs). [...] Read more.

This paper presents the influences of winding magneto-motive force (MMF) harmonics on the torque characteristics in surface-mounted permanent magnet vernier (SPMV) machines. Based on the magnetic gearing effects, the armature magnetic field of the SPMV machines is modulated by flux modulation poles (FMPs). In the modulated magnetic field, a working harmonic which corresponds to the number of the rotor pole pairs generates torque. Unlike regular PM machines, the winding MMF harmonics in the SPMV machines can produce the working harmonic by adjusting the FMP shapes. In order to investigate the effects of the winding MMF harmonics, the operating principle of the SPMV machines is elaborated by an analytical method using the winding MMF distribution and air-gap permeance function. After that, the design method of the FMP shapes that can improve the output torque by using the winding MMF harmonics is proposed. For the SPMV machine having 6 slots and 24 FMPs, the effects of the winding MMF harmonics and the validity of the proposed design method are confirmed by the finite element analysis method. It is shown that the proposed design method can improve the performances of the SPMV machine in terms of the torque density, induced electromagnetic force, and efficiency. Full article

(This article belongs to the Section D: Energy Storage and Application)

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14 pages, 5779 KB

Open AccessArticle

Electromagnetic Performance Analysis of Novel Flux-Regulatable Permanent Magnet Machines for Wide Constant-Power Speed Range Operation

by Yunchong Wang, Shuangxia Niu and Weinong Fu

Energies 2015, 8(12), 13971-13984; https://doi.org/10.3390/en81212407 - 10 Dec 2015

Cited by 11 | Viewed by 6275

Abstract

Two novel structures of permanent magnet (PM) machine, namely a hybrid excitation flux modulation machine (HEFMM) and a variable flux memory machine (VFMM), which have excellent field-weakening capability, are presented in this paper. The HEFMM incorporates the advantages of parallel hybrid excitation structure [...] Read more.

Two novel structures of permanent magnet (PM) machine, namely a hybrid excitation flux modulation machine (HEFMM) and a variable flux memory machine (VFMM), which have excellent field-weakening capability, are presented in this paper. The HEFMM incorporates the advantages of parallel hybrid excitation structure and flux modulation structure, so as to increase the torque density as well as increase the constant-power speed range. Inspired by the HEFMM, aiming to further improve the efficiency of machine, the VFMM with aluminum-nickel-cobalt (AlNiCo) PMs in the inner stator which can be magnetized by the current pulse of the direct current (DC) windings is developed. With double-stator structure, flux modulation effect in both machines can be employed to realize the hybrid excitation and regulate the air-gap flux density readily. The operation principle is illustrated and the static and steady performances of the machines are analyzed and compared with time stepping finite element analysis, which validates the effectiveness of the proposed designs. Full article

(This article belongs to the Special Issue Energy Efficient Actuators and Systems)

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