Modeling and analysis of a novel homopolar axial flux hub stepper motor

Abstract

The credit for the development of electric motor belongs to more than one individual as it is a process of development and discovery, beginning with the discovery of electromagnetism in 1820 and involving additional work by William Sturgeon, Joseph Henry, Andre Marie Ampere, Michael Faraday, Thomas Davenport and a few others. Nearing about 200 years, is newlinethe first developed electric motor by Michael Faraday following the discovery of electromagnetism by Hans Christian Oersted, in 1821. He demonstrated an apparatus that converts electrical energy into motion by homopolar phenomenon, a discovery that changed the course of electrical engineering. Presently Homopolar machines operating with unipolar flux are able to produce high and constant torque for wide speed range. Regardless of the success of radial-flux permanent-magnet machines, after the first patent by Davenport in 1837, axial-flux permanent magnet machines have also been under research interest particularly due to special application limited geometrical considerations. A possibility to obtain a very neat axial length for the machine makes axial-flux machines very attractive into applications like electric vehicles, in wheel motors, elevators in which the axial length of the machine is a limiting design parameter. They have usually been used in integrated high-torque applications. Stationary permanent magnet machines have the advantage of increased magnet life and hence high torque. For applications requiring high efficiency, compactness and low maintenance axial flux machines are the eminent solution. These machines are used in increasing numbers in aerospace, aviation and marine applications due to small weight and rugged construction features. newline newline