Permanent Magnet Vernier Machine Research Articles

Design and performance analysis of a novel flux-concentrating fault tolerant permanent magnet vernier machine for rim driven thruster

Design and performance analysis of a novel flux-concentrating fault tolerant permanent magnet vernier machine for rim driven thruster

Evaluation of magnetic orientation in dual-stator linear permanent magnet vernier machine for wave energy conversion

The Permanent Magnet Vernier Machine (PMVM) is favored for wave energy conversion due to its high torque production at low speeds and straightforward design. This study introduces the innovative Dual Stator Linear Permanent Magnet Vernier Machine (DSLPMVM) with concentrated winding. In this design, permanent magnets (PMs) are strategically placed on both the stator and a segmented translator, enhancing system reliability. The stator utilizes a simple PM layout, while the translator features a Halbach array. This research advances the DSLPMVM’s performance through the optimal placement and orientation of magnets, alongside a meticulous selection of tooth types. The paper rigorously evaluated all possible magnetic orientations and eight distinct stator tooth models. Detailed comparisons of flux linkage, back electromotive force (back-EMF), inductance, efficiency, power factor (PF), and force were conducted to identify the most effective designs.

A high torque dual 3-phase permanent magnet vernier machine with strong fault-tolerance

A high torque dual 3-phase permanent magnet vernier machine with strong fault-tolerance

Torque Ripple Suppression of a PM Vernier Machine From Perspective of Time and Space Harmonic Magnetic Field

Torque Ripple Suppression of a PM Vernier Machine From Perspective of Time and Space Harmonic Magnetic Field

Investigation of a Novel Phase-Unit Axial-Modular Permanent Magnet Vernier Machine With Integral-Slot Non-Overlapping Concentrated Windings

Investigation of a Novel Phase-Unit Axial-Modular Permanent Magnet Vernier Machine With Integral-Slot Non-Overlapping Concentrated Windings

Synthesis of Consequent Pole Vernier Permanent Magnet Machine Based on Oscillating Magnetic Potential Difference Model

Synthesis of Consequent Pole Vernier Permanent Magnet Machine Based on Oscillating Magnetic Potential Difference Model

Design and Analysis of Five-Phase Fault-Tolerant Vernier Permanent Magnet Machines for Direct-Drive Occasions

Abstract A fault-tolerant vernier permanent magnet machine (FTVPMM) with five phases for direct-drive occasions is designed and analyzed. The construction of the proposed FTVPMM is introduced and the principle of the vernier modulation effect is investigated. Parameters are designed and optimized by finite element analysis (FEA), including tooth width, slot opening, PM thickness, pole-arc coefficient, air-gap length, and rotor yoke. Furthermore, major electromagnetic performances are discussed, including cogging torque, no-load back electromotive force (BEMF), output torque, and fault-tolerant capability.

Investigation of Permanent-Magnet Vernier Machine With Fractional-Slot Nonoverlapping Windings for Direct-Drive Application

Investigation of Permanent-Magnet Vernier Machine With Fractional-Slot Nonoverlapping Windings for Direct-Drive Application

Comparative Analysis and Design Optimization of Ferrite-Based Surface PM Vernier Machines

This paper presents the results of a comprehensive investigation into the comparative analysis and design optimization of ferrite-based surface permanent magnet vernier machines (SPMVMs). While SPMVMs boast a simple mechanical structure and enhanced torque density attributed to the flux modulation effect, they suffer from a persistent challenge of low power factor. Several factors hinder the adoption of low-cost ferrite magnets in SPMVMs. First, ferrite magnets are prone to irreversible demagnetization, constraining the allowable range of magnet thickness. Second, the reduced residual magnetic flux density of ferrite magnets exacerbates the decrease in power factor and machine efficiency. Thus, achieving optimal performance in ferrite-based SPMVMs necessitates the careful selection of various design parameters. To address these issues, this study employs a surrogate-based metaheuristic optimization algorithm with adaptive sampling to identify the optimal solution. Additionally, the integration of a Halbach array is explored to further enhance the performance of the three-slot/two-pole SPMVM topology. Subsequently, two ferrite-based SPMVM baseline models—one with a conventional SPM structure and another with a Halbach magnet array—are thoroughly designed, optimized, and subjected to detailed performance analysis using the 2D finite element method.

Dual three Phase Operation of Dual Airgap Permanent Magnet Vernier Machine Having a Yokeless Rotor

Dual three Phase Operation of Dual Airgap Permanent Magnet Vernier Machine Having a Yokeless Rotor

Analysis and Comparison of Even-Order Back EMF Harmonics of Fractional-Slot Concentrated-Winding Consequent Pole Permanent Magnet Vernier Machines

Fractional-slot concentrated-winding (FSCW) consequent pole (CP) permanent magnet vernier (PMV) machines have received increasing attention due to their less magnet consumption but larger torque capability. However, the PM magnetomotive force (MMF) distribution is asymmetric in the CP structure. Thus, even-order air-gap flux density and back-electromotive force (back-EMF) harmonics are generated, which increases torque ripples. In this paper, to eliminate the even-order back-EMF harmonics and the resulting torque ripples, a comprehensive investigation on even-order flux density and back-EMF harmonics of five-phase FSCW CP PMV machines was presented, and then the general design rules without even-order back-EMF harmonics were summarized. Firstly, considering single- and double-layer windings, the effects of slot/pole number combination and flux modulator distribution on even-order flux density and back-EMF harmonics were analyzed. Secondly, the optimal slot/pole number combinations were selected, and then the rules for eliminating even-order back-EMF harmonics of CP PMV machines were summarized. As an extension, it was revealed that the harmonic elimination mechanism of CP PMV machines is applicable to CP-Halbach PMV machines. According to the summarized general design rules, the five-phase CP and CP-Halbach PMV machines with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> =20/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">P_r</i> =21/ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">z_f</i> =10 were proposed. Their detailed performance has been comparatively analyzed and then the optimal one was selected for prototyping. Both finite element analysis (FEA) and experiments were carried out to validate theoretical analyses.

Low Pole-Pair Ratio Integration Design of Permanent Magnet Vernier Machine With Improved Power Factor

Benefited from flux modulation effects, permanent magnet vernier machines (PMVMs) have the advantage of high torque. Generally, the higher pole-pair ratio ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> ), i.e., PM pole-pair to armature winding pole-pair, the stronger flux modulation effects, as well as the higher torque. However, PMVMs with high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> suffer from low power factor due to the parasitic large inductance. This paper is devoted to propose a low <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> integration design approach of PMVMs to achieve the high average torque and power factor simultaneously. According to exploit multiple working harmonics with low <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> s, not only the high power factor and low inductance characteristic can be maintained, but also the average torque and flux modulation effects can be strengthened. Further, the stator flux barrier has been added to restrict the parasitic no-working harmonics with high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> s. Based on these, two PMVM design examples with different slot/pole combinations are constructed and analyzed to verify the effectiveness of the proposed design approach. Finally, a prototype is manufactured and experimented. It is showed that under electric loading 320 A/cm, the active volume torque density of proposed PMVM can be up to 33.4 Nm/L, which is comparable to regular PMVM with high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PR</i> 8, while power factor can be improved from 0.63 to 0.8.

Comparative Analysis of Consequent-Pole PM Vernier Machines With Different Rotor Types

Taking advantage of flux modulation effects, consequent-pole PM vernier (CPMV) machines have been widely investigated recently, featuring high torque density and PM utilization ratio. However, the low-order harmonics of modulated flux fields additionally cause high iron saturation, which results in relatively low average torque under overload conditions, especially for the CPMV machines with an interior CPM (ICPM) rotor. Therefore, this paper proposes two hybrid CPM (HCPM) rotors of PMV machines to improve the overload performance by adding SPMs into the conventional ICPM rotor. First, the topologies of the proposed HCPM rotors are presented, named HCPM1 and HCPM2 rotors, respectively. Then the HCPM rotors and a conventional ICPM rotor with the V-shaped PM arrangement are designed and optimized to find out the optimal design parameters. Moreover, the electromagnetic performances including back-EMF, torque performance, efficiency, flux-weakening capability, and end effect are comprehensively investigated and compared. It indicates that the two proposed HCPM rotors both can generate equivalently high average torque, efficiency, and flux-weakening capability, compared to the conventional ICPM rotor. Furthermore, the proposed HCPM2 rotor can produce ≥22.9% higher torque at overload conditions. In addition, due to the bipolar PM arrangement, the unipolar flux leakage of the HCPM2 rotor is significantly reduced and lower than 0.05T. Finally, the prototype of a 12-stator-slot/ 20-rotor-pole CPMV machine with the HCPM2 rotor is manufactured to validate the finite element (FE) results.

Design Principle Considering Structural Mutual Effects of Double-Stator V-Shape-PM Vernier Machines for Electric Ship Propulsion

This paper proposes the design principle considering structural mutual effects of double-stator V-shape permanent-magnet (DS-V-PM) vernier machines for electric ship propulsion (ESP). Due to the flux concentration effect of the V-PM configuration, the double stators can be divided as a major and a minor stator, considering the different torque generation capability. Cooperation mutual effects between the double stators, V-PM arrangement and vernier machine topology are specifically included in the machine design principle exploration. To illustrate the design principle, first, a unified design principle is deduced, fit for general PM vernier machines. Then, a multi-step optimization strategy with auxiliary of sizing equations is presented, focusing on the parameter cooperation with flux modulation effect. Furthermore, through electromagnetic performance comparison, specific mutual effects of the DS configuration, DS angle shift, V-PMs and barrier structure are clearly summarized. Based on the DS machine design, the multi-mode operation for ESP system is introduced and analyzed. The normal/faulty cruise mode and charging mode are included to realize bi-directional operation. Prototype experiments are carried out for verification of the proposed machine design and operating strategy.

Subdomain Analytical Modeling of a Double-Stator Spoke-Type Permanent Magnet Vernier Machine

This paper proposes an analytical model of the double-stator spoke-type permanent magnet vernier machine (DSSTVM) using the subdomain method (SDM), which can be used to calculate the magnetic field distribution and corresponding electromagnetic parameters of the DSSTVM. The whole field domain is divided into several subdomains according to the magnetic characteristics of each region, within which Laplace’s and Poisson’s equations are solved accordingly in terms of magnetic vector potential (MVP). Then, the corresponding magnetic flux density distribution, back electromotive force (EMF), and electromagnetic torque of the DSSTVM can be obtained. Ultimately, finite element analysis (FEA) is adopted to validate the proposed analytical model’s effectiveness for quickly predicting the no-load and on-load performances of the DSSTVM.

Design and Research of Novel Consequent-Pole Dual PM Vernier Machines with Spoke and Halbach Array

Design and Research of Novel Consequent-Pole Dual PM Vernier Machines with Spoke and Halbach Array

Analytical calculation of magnetic field in surface-mounted permanent-magnet vernier motors

This paper proposes an analytical method to calculate the on-load magnetic field, Back electromotive force (BEMF) and torque of the surface-mounted permanent-magnet vernier machine (SMPMVM) accounting for slots, tooth-tips, flux modulation pole slots (FMPS) and the shape of magnet. The on-load magnetic field is predicted according to the surface-current method of permanent magnet, subdomain model and the superposition principle. BEMF and torque are calculated based on the magnetic field. The results show that THD of open-circuit and on-load radial flux density in the SMPMVM with concentric magnet poles is smaller than that in the conventional SMPMVM with eccentric magnet poles. 30th and 50th harmonic orders are obvious between two motors. Moreover, the peak cogging torque of the motor with concentric magnet poles is almost six times of the peak cogging torque of motor with eccentric magnet poles. The finite-element and experimental results confirm that the developed analytical method has high accuracy for predicting the magnetic field, BEMF, cogging torque and on-load electro-magnetic torque of SMPMVM with different shape of magnet.

A High Power Factor PM Vernier Machine with Segmented-Stator

A High Power Factor PM Vernier Machine with Segmented-Stator

Investigation of a Novel Dual-side PM Vernier Machine with Two-slot-pitch Coils

Investigation of a Novel Dual-side PM Vernier Machine with Two-slot-pitch Coils

Design of an L-Shaped Array Vernier Permanent Magnet Machine for Unmanned Aerial Vehicle Propulsion Using a Schwarz–Christoffel Mapping-Based Equivalent Magnetic Network Model

The Vernier permanent magnet (VPM) machines supersede conventional permanent magnet synchronous machine (PMSM) topologies in terms of torque-density and cogging torque. This paper presents a fractional-slot L-shaped magnet VPM machine, including peculiar designs for permanent magnet (PM) housing and rotor core construction for small-scale EVs such as unmanned aerial vehicles (UAVs). The idea for selecting the PM arrangement is based on combining the V-shaped and spoke-array PM topologies for achieving a higher torque-density than V-shaped PM machines and a lower cogging torque than spoke-array PM machines. The rotor core is created from non-integrated segments to form the flux-barriers in end-portions of PM housings. In this way, the leakage flux lines in the end-portion of the PMs reduce, resulting in enhanced flux linkage and power factor. A 630 W, 12-slot/8-pole motor is designed and prototyped for model validation purposes. An innovative equivalent magnetic network (EMN) model is established for analytical prediction of the performance of the machine. The Schwarz-Christoffel mapping is used to create the rotor core permeance network due to its special shaping. Two innovative pentagonal-shaped mesh cells are used in the air-gap region for more accurate capturing of flux behavior. The model is validated by comparing the results with the finite element results and experimental measurements.