Vernier Motor Research Articles

Improvement of Power Factor and Torque of a PM Vernier Motor From Perspective of Armature and PM Field Harmonics

Improvement of Power Factor and Torque of a PM Vernier Motor From Perspective of Armature and PM Field Harmonics

Comprehensive Performance Improvement of Permanent Magnet Vernier Motor for Electric Tractors

Comprehensive Performance Improvement of Permanent Magnet Vernier Motor for Electric Tractors

Rated Optimal Current Control Angle Identification for Surface Permanent Magnet Vernier Motor Considering Magnetic Saturation

Rated Optimal Current Control Angle Identification for Surface Permanent Magnet Vernier Motor Considering Magnetic Saturation

Multi-objective Optimization Design of Six-phase U-shaped Permanent Magnet Linear Vernier Motor

Multi-objective Optimization Design of Six-phase U-shaped Permanent Magnet Linear Vernier Motor

Analytical computation of magnetic field distribution in double-stator hybrid-excitation vernier motor based on an accurate subdomain model

Analytical computation of magnetic field distribution in double-stator hybrid-excitation vernier motor based on an accurate subdomain model

Design and Optimisation of a 5 MW Permanent Magnet Vernier Motor for Podded Ship Propulsion

The evolution of electric propulsion systems in the maritime sector has been influenced significantly by technological advancements in power electronics and machine design. Traditionally, these systems have employed surface-mounted permanent magnet synchronous motors (PMSMs) in podded configurations. However, the advent of permanent magnet Vernier motors (PMVMs), which leverage magnetic gearing effects, presents a novel approach with promising potential. This study conducts a comparative analysis between PMVMs and conventional PMSMs at a power level of 5 MW for podded ship propulsion, with a particular focus on the impact of gear ratios (Gr). An objective function was developed that integrates motor dimension constraints and the power factor (PF), a critical yet frequently neglected parameter in existing research. The findings indicate that PMVMs with lower Gr have lower mass and cost compared to those with higher Gr and traditional PMSMs, at a PF level of 0.7, which is high for Vernier machines. Moreover, PMVMs with lower Gr achieve efficiencies exceeding 99%, outperforming both their higher Gr counterparts and conventional PMSMs. The superior performance of PMVMs is attributed to lower current density and reduced copper loss, which contribute to their enhanced thermal performance. These details are elaborated on further in the paper. Consequently, these findings suggest that PMVMs with lower Gr are particularly well suited for high-power maritime propulsion applications, offering advantages in terms of compactness, efficiency (EF), cost-effectiveness, and thermal performance.

Multiharmonic-Layered Design and Optimization of a Flux-Concentrated PM Vernier Motor Considering Harmonic Sensitivity

Multiharmonic-Layered Design and Optimization of a Flux-Concentrated PM Vernier Motor Considering Harmonic Sensitivity

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.

Design and Analysis of a High Torque Performance Dual-Side PM Vernier Motor with Synergetic Modulation Enhancement

Design and Analysis of a High Torque Performance Dual-Side PM Vernier Motor with Synergetic Modulation Enhancement

Phase shift investigation of dual-three phase V-shaped PM vernier motor for improving torque and power factor

Permanent magnet vernier motor (PMVM) is extremely attractive in low-speed large-torque, whereas it always suffers from poor power factor. In order to realize the cooperative improvement of torque and power factor, this paper applies dual-three phase winding in PMVM, and investigates the influence of phase shift on torque and power factor improvement from the perspective of working harmonics and non-working harmonics. The key of this paper is to decompose the armature field harmonics. Through appropriated phase shift, increasing the armature working harmonics to improve the torque, and eliminating the armature non-working harmonics to enhance the power factor. Then the 24/38 DTP-PMVM is designed. Through theoretical derivation and simulation, it is verified that the DTP-PMVM torque is optimal and power factor is improved by phase shift 30°, compared with phase shift 0°.

Design and Analysis of a New Hybrid Excitation Vernier Motor with Reduced Permanent Magnet

Design and Analysis of a New Hybrid Excitation Vernier Motor with Reduced Permanent Magnet

A Mathematical and Dynamical Model for Analyzing H-Shaped PM Vernier Motor for Electric Motorcycle Mid-Drive Applications

A Mathematical and Dynamical Model for Analyzing H-Shaped PM Vernier Motor for Electric Motorcycle Mid-Drive Applications

Using Reluctance Torque Theory in Spoke Type Permanent Magnet Vernier Motors to Increase Average Torque

Using Reluctance Torque Theory in Spoke Type Permanent Magnet Vernier Motors to Increase Average Torque

Radial Displacement Sensorless Control at Low Speed Based on High-Frequency Voltage Injection for Bearingless Permanent Magnet Vernier Motor with Special Winding

Radial Displacement Sensorless Control at Low Speed Based on High-Frequency Voltage Injection for Bearingless Permanent Magnet Vernier Motor with Special Winding

Harmonic Loss Reduction of Fractional Slot Concentrated Winding Permanent-Magnet Vernier Motor with Different Stator-Modular Designs

Harmonic Loss Reduction of Fractional Slot Concentrated Winding Permanent-Magnet Vernier Motor with Different Stator-Modular Designs

Design and Comparative Analysis of Axial Flux Permanent Magnet Vernier Motors

This paper analytically investigates both the air gap flux density and the generated power of an Axial Flux Permanent Magnet Vernier Motor (AFPMVM). The AFPMVM has the same operational principle as a magnetic gear. It operates using space harmonics of the air gap flux density due to the magneto-motive force (MMF) and air gap permeance. This paper also examines the effect of various combinations of the rotor magnet pole pairs, stator slots, and winding pole numbers on the power factor and power density using the 3-D finite element method (3D-FEM). It is observed that, although having a higher pole ratio results in low cogging torque and high power density, it makes the machine length longer and has a lower power factor. Therefore, by employing the high pole ratios, the main advantage of the axial flux machines, i.e. having a shorter length, is sacrificed.

Design and Analysis of Consequent-Pole Permanent Magnet Vernier Motor With Cancellation of Even-Order Harmonics

Design and Analysis of Consequent-Pole Permanent Magnet Vernier Motor With Cancellation of Even-Order Harmonics

Comparison of Permanent Magnet Vernier Motors With Evenly and Unevenly Distributed Modulation Teeth

Permanent magnet vernier motor (PMVM) possesses the advantage of high torque density. In split-tooth PMVMs, the modulation teeth can be evenly or unevenly distributed on each stator tooth, which leads to the corresponding evenly and unevenly distributed slot vector diagrams. So, by selecting closer slot vectors into one phase, the winding factor can be improved, so the torque of PMVMs can be increased further by using the unevenly distributed modulation tooth structure. In this paper, two split-tooth PMVMs with evenly and unevenly distributed modulation teeth are compared. The simulation and the test results verify the correctness.

Comprehensive Armature Reaction Modeling and Flux Weakening Optimization of a Surface Permanent Magnet Vernier Motor

Surface permanent magnet vernier motors (SPMVMs) possess the potential for direct-drive applications due to the feature of high torque density. This paper presents a deep investigation into the armature reaction modeling and a semi-analytical optimization framework considering the constant power speed range (CPSR) in the flux weakening region for the SPMVM. The new armature reaction model can identify the armature air gap flux density of each harmonic component and armature flux linkage accurately, by conducting harmonics analysis, slot leakage flux computation and slotting effect evaluation, permitting to calculate the inductance. Then, the results from the armature reaction model and those obtained from finite element analysis (FEA) at the rated operating point together are applied to a comprehensive semi-analytical motor optimization framework developed for SPMVMs. The optimization framework is able to reflect the motor performance metrics over the entire speed range, with torque density, power factor and CPSR as objectives. Finally, a prototype designed according to the trade-offs of the optimization objectives is fabricated to confirm the validity of the armature reaction model and optimization framework.

Performance Comparison Between Permanent Magnet Synchronous Motor and Vernier Motor for In-Wheel Direct Drive

Nowadays, in-wheel drive mode is considered as one of the most promising modes for electric vehicles (EVs). The motor type plays a significant role to the vehicle performances. This paper focuses on performance between permanent magnet synchronous motor (PMSM) and vernier motor (PMVM) for in-wheel direct drive. Firstly, the required performances are determined by the vehicle requirements. The prototypes of PMVM and PMSM are manufactured after the comparison. Then, the expressions of air-gap magnetic field harmonic, electromagnetic torque, and power factor are theoretically derived, where the parameter torque ratio is introduced to evaluate the torque ratio between PMVM and PMSM. Based on experiment, the back-EMF harmonics, cogging torque, maximum torque per ampere capability, flux-weakening capability, torque, efficiency, power factor, are compared and analyzed. Subsequently, the discussions are carried out, where the strength and weakness of two-type motors for in-wheel drive are concluded and the future prospects are suggested. Finally, the conclusions of two-type in-wheel motors are then extracted. This paper aims at providing a reference for the exploration of alternating in-wheel motor types, which can promote the development of high-performance in-wheel drive system for EVs.