scholarly journals Investigation of a New Flux-Modulated Permanent Magnet Brushless Motor for EVs

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ying Fan ◽  
Lingling Gu ◽  
Yong Luo ◽  
Xuedong Han ◽  
Ming Cheng

This paper presents a flux-modulated direct drive (FMDD) motor. The key is to integrate the magnetic gear with the PM motor while removing the gear inner-rotor. Hence, the proposed FMDD motor can achieve the low-speed high-torque output and high-speed compact design requirements as well as high-torque density with a simple structure. The output power equation is analytically derived. By using finite element analysis (FEA), the static characteristics of the proposed motor are obtained. Based on these characteristics, the system mathematical model can be established. Hence, the evaluation of system performances is conducted by computer simulation using the Matlab/Simulink. A prototype is designed and built for experimentation. Experimental results are given to verify the theoretical analysis and simulation.

Proceedings ◽  
2020 ◽  
Vol 64 (1) ◽  
pp. 11
Author(s):  
Akash Singh ◽  
Navvab Kashiri ◽  
Nikolaos Tsagarakis

In recent years, several legged/wheeled robots have been developed, and their effective functionality in locomotion on uneven terrains has been proved. Many robotics researchers have been focusing on improving the locomotion speed as well as the stability and robustness of such robots. High-speed locomotion of robots is, however, subject to various design challenges, especially in the development of actuators. The robotic applications that require high-speed motion in high-torque operations along with the ability to manage dynamic physical interactions are not satisfied by the conventional robotic actuators deploying high-reduction gearings. In this work, we present a quasi-direct-drive actuator designed for continuous high-speed motions in high torque, such as wheeled motions in mobile robots or joint motions in dynamic-legged robots. The presented actuator exploits low-reduction gearing so that it can render over 26 Nm of continuous torque, while the actuator speed can exceed 37 rad/s. Such characteristics enable the exhibition of dynamic motions and can deal with large external impacts. The selection of the motor and design of the gearing unit was carried out iteratively so that commercial items with minimum customization could be employed and the outer diameters of the motor and the gearbox could match. A single-level planetary gearbox was devised for the reduction unit to ensure high back-drivability and transparency of the actuator, thereby making the actuator robust against external impacts and allowing for accurate torque control using motor current measurement. The gear set design was carried out based on the AGMA gear torque calculation. Given the radial space required for the gearbox to deal with the torque requirements, the actuator motor was chosen to be small in height (pancake type), which ensures high torque density within smaller dimensions at high-speed operation. The mechanical design of the actuator is presented in this paper, and the actuator’s specifications in terms of size and performance are compared with those of similar state-of-the-art actuators.


2012 ◽  
Vol 06 ◽  
pp. 109-114
Author(s):  
BYUNG-CHUL WOO ◽  
DO-KWAN HONG ◽  
JI-YOUNG LEE

The most distinctive advantage of transverse flux motor(TFM) is high torque density which has prompted many researches into studying various design variants. TFM is well suited for low speed direct drive applications due to its high torque density. This paper deals with simulation based comparisons between a surface permanent magnet transverse flux motor(SPM-TFM) and an interior permanent magnet transverse flux motor(IPM-TFM). A commercial finite element analysis(FEA) software Maxwell 3D is used for electromagnetic field computation to fully analyze complex geometry of the TFMs. General characteristics, such as cogging torque, rated torque and torque ripple characteristics of the two TFMs are analyzed and compared by extensive 3D FEA.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4407
Author(s):  
Mbika Muteba

There is a necessity to design a three-phase squirrel cage induction motor (SCIM) for high-speed applications with a larger air gap length in order to limit the distortion of air gap flux density, the thermal expansion of stator and rotor teeth, centrifugal forces, and the magnetic pull. To that effect, a larger air gap length lowers the power factor, efficiency, and torque density of a three-phase SCIM. This should inform motor design engineers to take special care during the design process of a three-phase SCIM by selecting an air gap length that will provide optimal performance. This paper presents an approach that would assist with the selection of an optimal air gap length (OAL) and optimal capacitive auxiliary stator winding (OCASW) configuration for a high torque per ampere (TPA) three-phase SCIM. A genetic algorithm (GA) assisted by finite element analysis (FEA) is used in the design process to determine the OAL and OCASW required to obtain a high torque per ampere without compromising the merit of achieving an excellent power factor and high efficiency for a three-phase SCIM. The performance of the optimized three-phase SCIM is compared to unoptimized machines. The results obtained from FEA are validated through experimental measurements. Owing to the penalty functions related to the value of objective and constraint functions introduced in the genetic algorithm model, both the FEA and experimental results provide evidence that an enhanced torque per ampere three-phase SCIM can be realized for a large OAL and OCASW with high efficiency and an excellent power factor in different working conditions.


Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3639
Author(s):  
Rundong Huang ◽  
Chunhua Liu ◽  
Zaixin Song ◽  
Hang Zhao

Electric machines with high torque density are needed in many applications, such as electric vehicles, electric robotics, electric ships, electric aircraft, etc. and they can avoid planetary gears thus reducing manufacturing costs. This paper presents a novel axial-radial flux permanent magnet (ARFPM) machine with high torque density. The proposed ARFPM machine integrates both axial-flux and radial-flux machine topologies in a compact space, which effectively improves the copper utilization of the machine. First, the radial rotor can balance the large axial forces on axial rotors and prevent them from deforming due to the forces. On the other hand, the machine adopts Halbach-array permanent magnets (PMs) on the rotors to suppress air-gap flux density harmonics. Also, the Halbach-array PMs can reduce the total attracted force on axial rotors. The operational principle of the ARFPM machine was investigated and analyzed. Then, 3D finite-element analysis (FEA) was conducted to show the merits of the ARFPM machine. Demonstration results with different parameters are compared to obtain an optimal structure. These indicated that the proposed ARFPM machine with Halbach-array PMs can achieve a more sinusoidal back electromotive force (EMF). In addition, a comparative analysis was conducted for the proposed ARFPM machine. The machine was compared with a conventional axial-flux permanent magnet (AFPM) machine and a radial-flux permanent magnet (RFPM) machine based on the same dimensions. This showed that the proposed ARFPM machine had the highest torque density and relatively small torque ripple.


2011 ◽  
Vol 215 ◽  
pp. 89-94 ◽  
Author(s):  
Jing Zhu Pang ◽  
Bei Zhi Li ◽  
Jian Guo Yang ◽  
Zhou Ping Wu

This paper presents the effects of spindle system configuration on the dynamic and static characteristics of high speed grinding. A 3D physical mode of high-speed grinding motorized spindle system with rotation speed of 150m/s was provided. The motorized spindle system consists of bearings, rotor, stator, spindle housing and grinding wheel. Based on the finite element method (FEM), the static characteristics, dynamic and the transient response are analyzed based on the finite element analysis software NASTRAN. It is shown that the spindle overhanging, bearing span have a significant effort on spindle deflection. The dynamic analysis shows no resonance will happen during its speed range. The methods and solutions for the motorized spindle system design and engineering applications was given in this paper.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Chang Wu ◽  
Zi-Heng Sun

The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC) hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA) software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.


Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1238 ◽  
Author(s):  
Dong Yu ◽  
Xiaoyan Huang ◽  
Lijian Wu ◽  
Youtong Fang

This paper presents a novel outer rotor permanent-magnet vernier machine (PMVM) for in-wheel direct-drive application. The overhang structures of the rotor and flux modulation pole (FMP) are introduced. The soft magnetic composite (SMC) was adopted in the FMP overhang to allow more axial flux. The 3-D finite element analysis (FEA) was carried out to prove that the proposed machine can effectively utilize the end winding space to enhance the air-gap flux density. Hence the PMVM can offer 27.3% and 14.5% higher torque density than the conventional machine with no overhang structure and the machine with only rotor overhang structure, respectively. Nevertheless, the efficiency of the proposed machine is slightly lower than the conventional ones due to the extra losses from the overhang structures.


2011 ◽  
Vol 80-81 ◽  
pp. 927-931 ◽  
Author(s):  
Yan Qing Wang ◽  
Gao Yan Zhong ◽  
Yong Biao Chang ◽  
Guo Xin Liu

The stroke and the material characteristics of the large five-axis machining center were expounded; a structure similar to the truss of the reinforced beam plates was designed according to the design requirements of the beam structure, this structure could make the frame gain high rigidity in small size, the frame made by the rods could be constituted with high rigidity, the overall rigidity of the machining center could be improved 23% - 25%; three different beam structures were designed, and the finite element analysis software ANSYS was carried out to analyze their static characteristics, the maximum deformations in three directions X, Y, Z were obtained; compared with other structures through the comparisons on mass, stiffness and performance, the optimal structure was obtained, its mass was 1818Kg, and its maximum deformations in X, Y, Z directions were 0.45mm, 0.07mm and 0.13mm, respectively.


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