Author: Iftekhar Hasan
Publisher:
ISBN:
Category : Electric machines
Languages : en
Pages : 125
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Commercially available permanent magnet synchronous machines (PMSM) typically use rare-earth-based permanent magnets (PM). However, volatility and uncertainty associated with the supply and cost of rare-earth magnets have caused a push for increased research into the development of non-rare-earth based PM machines and reluctance machines. Compared to other PMSM topologies, the Transverse Flux Machine (TFM) is a promising candidate to get higher torque densities at low speed for direct-drive applications, using non-rare-earth based PMs. The TFMs can be designed with a very small pole pitch which allows them to attain higher force density than conventional radial flux machines (RFM) and axial flux machines (AFM).This dissertation presents the modeling, electromagnetic design, vibration analysis, and prototype development of a novel non-rare-earth based PM-TFM for a direct-drive wind turbine application. The proposed TFM addresses the issues of low power factor, cogging torque, and torque ripple during the electromagnetic design phase.An improved Magnetic Equivalent Circuit (MEC) based analytical model was developed as an alternative to the time-consuming 3D Finite Element Analysis (FEA) for faster electromagnetic analysis of the TFM. The accuracy and reliability of the MEC model were verified, both with 3D-FEA and experimental results. The improved MEC model was integrated with a Particle Swarm Optimization (PSO) algorithm to further enhance the capability of the analytical tool for performing rigorous optimization of performance-sensitive machine design parameters to extract the highest torque density for rated speed.A novel concept of integrating the rotary transformer within the proposed TFM design was explored to completely eliminate the use of magnets from the TFM. While keeping the same machine envelope, and without changing the stator or rotor cores, the primary and secondary of a rotary transformer were embedded into the double-sided TFM. The proposed structure allowed for improved flux-weakening capabilities of the TFM for wide speed operations.The electromagnetic design feature of stator pole shaping was used to address the issue of cogging torque and torque ripple in 3-phase TFM. The slant-pole tooth-face in the stator showed significant improvements in cogging torque and torque ripple performance during the 3-phase FEA analysis of the TFM. A detailed structural analysis for the proposed TFM was done prior to the prototype development to validate the structural integrity of the TFM design at rated and maximum speed operation. Vibration performance of the TFM was investigated to determine the structural performance of the TFM under resonance.The prototype for the proposed TFM was developed at the Alternative Energy Laboratory of the University of Akron. The working prototype is a testament to the feasibility of developing and implementing the novel TFM design proposed in this research. Experiments were performed to validate the 3D-FEA electromagnetic and vibration performance result.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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A novel transverse flux machine topology for electric vehicle traction applications using ferrite magnets is presented in this paper. The proposed transverse flux topology utilizes novel magnet arrangements in the rotor that are similar to the Halbach array to boost flux linkage; on the stator side, cores are alternately arranged around a pair of ring windings in each phase to make use of the entire rotor flux that eliminates end windings. Analytical design considerations and finite-element methods are used for an optimized design of a scooter in-wheel motor. Simulation results from finite element analysis (FEA) show that the motor achieved comparable torque density to conventional rare-earth permanent magnet (PM) machines. This machine is a viable candidate for direct-drive applications with low cost and high torque density.
Author: Wenqiang Chu
Publisher:
ISBN:
Category :
Languages : en
Pages :
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This thesis is focused on the comparative investigation on the torque characteristics, both average torque and torque ripple, of permanent magnet (PM) and electrically excited (EE) machines for direct drive applications, which require both high torque density and low torque ripple. The effectiveness of two of the most widely used methods, i.e., rotor shaping and skewing, for torque ripple reduction in EE and PM machines is investigated. It is found that the effectiveness of skewing largely depends on the axial variation of torque ripple phase but less on its magnitude under skewing. It is further found that, in both linear and nonlinear cases, the on-load torque ripple cannot be fully eliminated by skewing one on-load torque ripple period or any other angles, except 360o electrical, which is impractical. The torque ripple may be even increased by skewing, especially when the cogging torque is low and electric loading is high. An improved skewing is developed by optimising both the skewing and current phase advance angles when the conventional skewing method fails. Compared with PM machines, rotor shaping is less effective on torque ripple reduction in EE machines due to the asymmetric magnetic saturation of the stator and rotor cores. However, if rotor skewing is used then EE machines can still achieve the same low level of torque ripple as PM machines. In order to better understand characteristics of on-load torque and hence improve it, the on-load torque separation of PM machines is investigated as well. It is found that the average torque components can be appropriately separated using the virtual work principle but not by the Maxwell stress tensor. For the on-load cogging torque calculation, which is the most difficult challenge for on-load torque ripple separation, a new method is proposed by combining the virtual work principle with an improved frozen permeability method. For torque density optimisation, analytical methods are often desirable. This thesis develops an analytical model for PM machines having external rotor. It is shown that the torque density is maximum when the average airgap flux density is slightly lower than half of the maximum flux density in the stator. In order to compare the torque densities between EE and PM machines, a simplified analytical model of EE machines is developed as well. It is shown that, for EE machines, there is an optimal pole number to maximize the torque densities and it is more advantageous for large volume applications. PM machines can exhibit higher than √2 times torque densities of EE machines. The designs of maximum torque per weight are more cost-effective and result in a significantly larger airgap diameter than the designs of maximum torque per volume.
Author: Sławomir Wiak
Publisher: IOS Press
ISBN: 1607506033
Category : Science
Languages : en
Pages : 968
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Book Description
Computer Field Models of Electromagnetic Devices, volume 34 in the book series Studies in Applied Electromagnetics and Mechanics is devoted to modeling and simulation, control systems, testing, measurements, monitoring, diagnostics and advanced software
Author: Datong Qin
Publisher: CRC Press
ISBN: 131538681X
Category : Technology & Engineering
Languages : en
Pages : 1081
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Book Description
This book presents papers from the International Conference on Power Transmissions 2016, held in Chongqing, China, 27th-30th October 2016. The main objective of this conference is to provide a forum for the most recent advances, addressing the challenges in modern mechanical transmissions. The conference proceedings address all aspects of gear and power transmission technology and a range of applications. The presented papers are catalogued into three main tracks, including design, simulation and testing, materials and manufacturing, and industrial applications. The design, simulation and testing track covers topics such as new methods and designs for all types of transmissions, modelling and simulation of power transmissions, strength, fatigue, dynamics and reliability of power transmissions, lubrication and sealing technologies and theories, and fault diagnosis of power transmissions. In the materials and manufacturing track, topics include new materials and heat treatment of power transmissions, new manufacturing technologies of power transmissions, improved tools to predict future demands on production systems, new technologies for ecologically sustainable productions and those which preserve natural resources, and measuring technologies of power transmissions. The proceedings also cover the novel industrial applications of power transmissions in marine, aerospace and railway contexts, wind turbines, the automotive industry, construction machinery, and robots.
Author:
Publisher: World Scientific
ISBN: 9813270187
Category : Technology & Engineering
Languages : en
Pages : 2064
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Book Description
The five-volume set may serve as a comprehensive reference on electromagnetic analysis and its applications at all frequencies, from static fields to optics and photonics. The material includes micro- and nanomagnetics, the new generation of electric machines, renewable energy, hybrid vehicles, low-noise motors; antennas and microwave devices, plasmonics, metamaterials, lasers, and more.Written at a level accessible to both graduate students and engineers, Electromagnetic Analysis is a comprehensive reference, covering methods and applications at all frequencies (from statics to optical). Each volume contains pedagogical/tutorial material of high archival value as well as chapters on state-of-the-art developments.
Author: Christopher Paul Maddison
Publisher:
ISBN:
Category :
Languages : en
Pages : 237
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Author: Zhao Wan
Publisher:
ISBN:
Category :
Languages : en
Pages : 96
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Author: Jacek F. Gieras
Publisher: Springer Science & Business Media
ISBN: 1402082274
Category : Technology & Engineering
Languages : en
Pages : 365
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Book Description
Axial Flux Permanent Magnet (AFPM) brushless machines are modern electrical machines with a lot of advantages over their conventional counterparts. This timeless and revised second edition deals with the analysis, construction, design, control and applications of AFPM machines. The authors present their own research results, as well as significant research contributions made by others.
Author: Asko Parviainen
Publisher:
ISBN: 9789522140302
Category :
Languages : en
Pages : 153
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Book Description
