eLearning

Cogging Torque Analysis of Magnetic Gear

Noboru Niguchi; Katsuhiro Hirata IEEE Transactions on Industrial Electronics, 2012

This paper describes the harmonic spectra of the cogging torque of a magnetic gear. The operating principle of this gear is described, and the transmission torque under operation in accordance with the gear ratio is mathematically formulated. In particular, the harmonic order of the cogging torque is described in detail. Moreover, the orders of the cogging torque of both rotors ...

A simple method to improve the sinusoidal static characteristics of doubly- salient PM machine for brushless AC operation

Ming Cheng; Wei Hua; X. Y. Zhu; W. X. Zhao; H. Y. Jia 2007 International Conference on Electrical Machines and Systems (ICEMS), 2007

This paper investigates a simple method for a doubly-salient permanent magnet motor to improve the static characteristics to be more sinusoidal, including the back-EMF and the phase inductances waveforms, as well as less cogging torque for brushless AC operation. The optimal skewing angle of the rotor is evaluated by finite element analysis and validated by experimental results. The vector control ...

A comparative study of winding factors between distributed windings and non-overlapping concentrated windings

Deming Zhu; Xin Qiu; Nan Zhou; Yangguang Yan 2008 Third International Conference on Electric Utility Deregulation and Restructuring and Power Technologies, 2008

Distributed windings have been extensively equipped in permanent magnet synchronous machine (PMSM) because of their inherent sinusoidal electromotive force (EMF) waveform. Recent work by the authors shows the differences of winding factors between non-overlapping windings and its distributed windings counterpart. The winding factors of non- overlapping concentrated windings eliminate only part of EMF waveform harmonics. Latter suggestion is that with ...

Reducing Cogging Torque in Surface-Mounted Permanent-Magnet Motors by Nonuniformly Distributed Teeth Method

Daohan Wang; Xiuhe Wang; Dongwei Qiao; Ying Pei; Sang-Yong Jung IEEE Transactions on Magnetics, 2011

This paper proposed a novel method for reducing cogging torque in surface- mounted permanent-magnet (PM) motors with nonuniformly distributed teeth. In this method, the width of one tooth tip is different from that of the others while all slot openings are the same. By suitable selection of the teeth width ratio, i.e., the width ratio of the one tooth tip ...

Reducing the cogging torque in brushless DC motors by using conformal mappings

M. Markovic; M. Jufer; Y. Perriard IEEE Transactions on Magnetics, 2004

We present an exact model for determining the cogging torque in a brushless DC (BLDC) motor. It is based on the conformal mapping (CM) method, by which the motor configuration is transformed to a configuration where the magnetic field can be determined. Then, by integrating the field over the stator surface, the cogging torque is determined. By varying some motor ...

IEEE-USA E-Books

• The Education Arcade

  This chapter contains sections titled: The Standard Drill, Roots, Re- Rebranding, Forging Ahead with Media Partnerships

• Generator Design and Construction

  This chapter contains sections titled: Stator Core Stator Frame Flux and Armature Reaction Electromagnetics End-Region Effects and Flux Shielding Stator Core and Frame Forces Stator Windings Stator Winding Wedges End-Winding Support Systems Stator Winding Configurations Stator Terminal Connections Rotor Forging Rotor Winding Rotor Winding Slot Wedges Amortisseur Winding Retaining Rings Bore Copper and Terminal Connectors Slip-Collector Rings and Brush Gear Rotor Shrink Coupling Rotor Turning Gear Bearings Air and Hydrogen Cooling Rotor Fans Hydrogen Containment Hydrogen Coolers References

• Contested Dynamos and Wires: Tribunals of Technologies, Ownership, and Identities

  This chapter contains sections titled: 5.1 Claiming the "Dynamo": Wilde vs. Thompson, 5.2 Winding Dynamos, Ownership, and Authority: Forging Credit as Reputation, 5.3 Credit Battles in Court: The Disputes over Dynamo Winding, 5.4 "Lame Fox" vs. the Supply Companies, 5.5 Conclusion

• Inventing the Invention of Wireless Telegraphy: Marconi versus Lodge

  This chapter contains sections titled: Fleming's Marconi Memorial Lecture of 1937, Hertzian Waves and ???Lodgian??? Practice in 1894, Marconi, Preece, the Maxwellians, and ???Practice vs. Theory???, Marconi's Patent ???for Everything???, Forging Lodge's Priority

• Generator Design and Construction

  This chapter contains sections titled: Stator Core Stator Frame Flux and Armature Reaction Electromagnetics End-Region Effects and Flux Shielding Stator Core and Frame Forces Stator Windings Stator Winding Wedges End-Winding Support Systems Stator Winding Configurations Stator Terminal Connections Rotor Forging Rotor Winding Rotor Winding Slot Wedges Amortisseur Winding Retaining-Rings Bore Copper and Terminal Connectors Slip-Collector Rings and Brush-Gear Rotor Shrink Coupling Rotor Turning Gear Bearings Air and Hydrogen Cooling Rotor Fans Hydrogen Containment Hydrogen Coolers References

• No title

  In the past 50 years there has been an explosion of interest in the development of technologies whose end goal is to connect the human brain and/or nervous system directly to computers. Once the subject of science fiction, the technologies necessary to accomplish this goal are rapidly becoming reality. In laboratories around the globe, research is being undertaken to restore function to the physically disabled, to replace areas of the brain damaged by disease or trauma and to augment human abilities. Building neural interfaces and neuro-prosthetics relies on a diverse array of disciplines such as neuroscience, engineering, medicine and microfabrication just to name a few. This book presents a short history of neural interfacing (N.I.) research and introduces the reader to some of the current efforts to develop neural prostheses. The book is intended as an introduction for the college freshman or others wishing to learn more about the field. A resource guide is included for students al ng with a list of laboratories conducting N.I. research and universities with N.I. related tracks of study. Table of Contents: Neural Interfaces Past and Present / Current Neuroprosthesis Research / Conclusion / Resources for Students