Transverse Flux Machine (TFM) designs are, in general, based on 3-D Finite Element Methods (FEM). Previous attempts to perform analytical designs have been limited to Magnetic Equivalent Circuits (MEC). In this paper, for the first time, propulsion force calculation of TFMs is performed using an extremely fast analytical model. This allows for fast optimization routines to be implemented on the complex 3-D TFM structure. The derived analytical model combines magnetic charge and magnetic imaging techniques to obtain the magnetic air gap flux density distribution. Further, to allow calculation of the propulsion force in a direct manner, a suitable current sheet representation had to be drawn from the TFM structure. This equivalent representation of the magnetomotiveforce (mmf) in the stator, contained on a 2-D surface at the air gap centre, allowed the application of Lorentz force to this complex 3-D structure. This resulted in an analytical technique to accurately calculate propulsion force with a 2% deviation compared to 3-D FEM when the width of tooth and PM are similar, although that it does not yet allow for accurate cogging force calculations. In retrospect, also relatively accurate results, below 10%, are obtained for the flux density distribution in the air gap centre.
|Title of host publication
|Proceedings of the 11th International Conference on Modeling and Simulation of Electric Machines, Converters and Systems (ElectrIMACS 2014), 19-22 May 2014, Valencia, Spain
|Published - 2014