Comparison of 3-dimensional and 1-dimensional calculation of the thrust of a sector motor

The 1-dimensional analysis of a sector motor is described. Many assumptions, such as neglecting the magnetic field outside the edges of the airgap and supposing axial flow of induced eddy currents on the rotor surface, are made. The wide variation of the relative permeability of the rotor is approximated by a constant average value. The method shows how the rotating field theory can be modified to make it useful in the analysis of a motor with a pole pitch different from 180 electrical degrees. Results calculated, using this method, are compared with those obtained from a 3-dimensional analysis and the experimental values given by Bolte [2].