Rotor Pole Design of Radial Flux Magnetic Gear for Reduction of Flux Density Harmonics and Cogging Torque

2019 ◽  
Vol 29 (8) ◽  
pp. 1-8
Author(s):  
Seyed Ahmadreza Afsari Kashani
Keyword(s):  
Flux Density ◽  
Cogging Torque ◽  
Radial Flux ◽  
Rotor Pole ◽  
Magnetic Gear

scholarly journals Design and Analysis of a Dual Airgap Radial Flux Permanent Magnet Vernier Machine with Yokeless Rotor

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2311
Author(s):  
Mudassir Raza Siddiqi ◽  
Tanveer Yazdan ◽  
Jun-Hyuk Im ◽  
Muhammad Humza ◽  
Jin Hur
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Magnet ◽  
Flux Linkage ◽  
Element Analysis ◽  
Cogging Torque ◽  
Torque Density ◽  
Stator Windings ◽  
Radial Flux ◽  
Torque Ripples

This paper presents a novel topology of dual airgap radial flux permanent magnet vernier machine (PMVM) in order to obtain a higher torque per magnet volume and similar average torque compared to a conventional PMVM machine. The proposed machine contains two stators and a sandwiched yokeless rotor. The yokeless rotor helps to reduce the magnet volume by providing an effective flux linkage in the stator windings. This effective flux linkage improved the average torque of the proposed machine. The competitiveness of the proposed vernier machine was validated using 2D finite element analysis under the same machine volume as that of conventional vernier machine. Moreover, cogging torque, torque ripples, torque density, losses, and efficiency performances also favored the proposed topology.

scholarly journals DESIGN OF A SINGLE-PHASE RADIAL FLUX PERMANENT MAGNET GENERATOR WITH VARIATION OF THE STATOR DIAMETER

2019 ◽  
Vol 81 (4) ◽  
Author(s):  
Hari Prasetijo ◽  
Winasis Winasis ◽  
Priswanto Priswanto ◽  
Dadan Hermawan
Keyword(s):  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Single Phase ◽  
Air Gap ◽  
Wire Diameter ◽  
Terminal Phase ◽  
Magnetic Flux Density ◽  
Phase Voltage ◽  
Radial Flux

This study aims to observe the influence of the changing stator dimension on the air gap magnetic flux density (Bg) in the design of a single-phase radial flux permanent magnet generator (RFPMG). The changes in stator dimension were carried out by using three different wire diameters as stator wire, namely, AWG 14 (d = 1.63 mm), AWG 15 (d = 1.45 mm) and AWG 16 (d = 1.29 mm). The dimension of the width of the stator teeth (Wts) was fixed such that a larger stator wire diameter will require a larger stator outside diameter (Dso). By fixing the dimensions of the rotor, permanent magnet, air gap (lg) and stator inner diameter, the magnitude of the magnetic flux density in the air gap (Bg) can be determined. This flux density was used to calculate the phase back electromotive force (Eph). The terminal phase voltage (V∅) was determined after calculating the stator wire impedance (Z) with a constant current of 3.63 A. The study method was conducted by determining the design parameters, calculating the design variables, designing the generator dimensions using AutoCad and determining the magnetic flux density using FEMM simulation.  The results show that the magnetic flux density in the air gap and the phase back emf Eph slightly decrease with increasing stator dimension because of increasing reluctance. However, the voltage drop is more dominant when the stator coil wire diameter is smaller. Thus, a larger diameter of the stator wire would allow terminal phase voltage (V∅) to become slightly larger. With a stator wire diameter of 1.29, 1.45 and 1.63 mm, the impedance values of the stator wire (Z) were 9.52746, 9.23581 and 9.06421 Ω and the terminal phase voltages (V∅) were 220.73, 221.57 and 222.80 V, respectively. Increasing the power capacity (S) in the RFPMG design by increasing the diameter (d) of the stator wire will cause a significant increase in the percentage of the stator maximum current carrying capacity wire but the decrease in stator wire impedance is not significant. Thus, it will reduce the phase terminal voltage (V∅) from its nominal value.

Magnetic Flux Analysis of E-Core Hybrid Excited FSM with Various Rotor-Pole Topologies

2014 ◽  
Vol 695 ◽  
pp. 774-777
Author(s):  
Siti Nur Umira Zakaria ◽  
Erwan Sulaiman
Keyword(s):  
Magnetic Flux ◽  
High Speed ◽  
Flux Distribution ◽  
Flux Analysis ◽  
Flux Linkage ◽  
Cogging Torque ◽  
Excitation Coil ◽  
Rotor Pole ◽  
Field Excitation ◽  
Flux Path

This paper presents magnetic flux analysis of E-Core Hybrid Excited FSM with various rotor pole topologies. The stator consists of three active fluxes sources namely armature coil, field excitation coil and permanent magnet, while the rotor consists of only stack of iron which is greatly reliable for high speed operation. Initially, coil arrangement tests are examined to validate the operating principle of the motor and to identify the zero rotor position. Then, performances of 6S-4P, 6S-5P, 6S-7P and 6S-8P E-Core HEFSMs such as flux path, flux linkage, cogging torque and flux distribution are observed. As conclusion, 6S-5P and 6S-7P designs have purely sinusoidal flux waveform and less cogging torque suitable for high torque and power motor.

Cogging Torque Analysis of Novel Dual-Rotor Axial Field Flux-Switching Permanent Magnet Machine

2013 ◽  
Vol 416-417 ◽  
pp. 276-280 ◽  
Author(s):  
Li Hao ◽  
Ming Yao Lin ◽  
Da Xu ◽  
Xing He Fu ◽  
Wei Zhang
Keyword(s):  
Permanent Magnet ◽  
Design Parameters ◽  
Original Design ◽  
Axial Field ◽  
Cogging Torque ◽  
Tooth Width ◽  
Rotor Pole ◽  
Torque Analysis ◽  
Slot Opening ◽  
3D Finite Element Method

The cogging torque of a novel dual-rotor axial field flux-switching permanent magnet (DRAFFSPM) machine is investigated in this paper. The analytical equation of the DRAFFSPM machine is deduced. Based on 3D finite element method, the influences of the design parameters on the cogging torque are analyzed. The H-shaped stator tooth with slot chamfer is proposed and the slot opening width and chamfer thickness are optimized to reduce the cogging torque. It shows that the cogging torque is the minimum when the stator tooth width and stator magnet width equal to 8o and 7.5o mech., respectively. The cogging torque can be reduced by ~64% when the rotor pole width is 1.6 times that of the original design. The cogging torque can be reduced by ~80% when the chamfer is added in the stator slot.

Study on Improvement of Transmission Torque for a Surface Permanent Magnet Type Magnetic Gear

2012 ◽  
Vol 721 ◽  
pp. 237-242 ◽  
Author(s):  
Masaru Oka ◽  
Takashi Todaka ◽  
Masato Enokizono ◽  
Kousuke Nagaya ◽  
Tomoyuki Fujita
Keyword(s):  
Permanent Magnet ◽  
Flux Density ◽  
Flux Distribution ◽  
Permanent Magnets ◽  
Torque Density ◽  
Magnetic Forces ◽  
Dimensional Finite Element ◽  
Flux Concentration ◽  
Magnetic Gear ◽  
Flux Density Distribution

Magnetic gears are a force transmitter consisting of permanent magnets. The mechanical input can be transmitted to an output shaft without contact by magnetic forces. The magnetic gears are not worn out because there is no friction. As a result, the running costs such as the maintenance fee can be suppressed and the resources can be saved. However, the transmission torques of the conventional magnetic gears, which have so far been developed, are very low. Besides, new structure models designed for high torque density need a lot of permanent magnets and multi-pole constructions. Those structures are complex and the manufacturing is difficult. In this research, we applied a flux concentration type surface permanent magnet arrangement to a surface permanent magnet type magnetic gear in order to improve the transmission torque and to reduce the amount of permanent magnets. The magnetic flux distribution, the gap flux density and the transmission torque of the developed new models are numerically analyzed by using the two-dimensional finite element method. In this paper, a permanent magnet structure optimized to reduce its amount and influence of the flux concentration type surface permanent magnet arrangement on the gap flux density distribution and transmission torque are reported.

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