Equivalence between the method of magnetic images and the variable separation method in the study of some slotless surface permanent magnet synchronous machines

In the present paper, the equivalence between the magnetic images method an d the classical variable separation method is set up. These methods are sep arately applied to calculate the magnetic scalar potentials and the magneti c vector potentials in the air-gap of some cylindrical synchronous machines , excited by surface permanent magnets with radial and/or azimuthal magneti sation, and without polar pieces. The rotor and the stator are assumed slot less, and the whole electric machine non saturated. The expressions of the magnetic scalar potentials of each method are interpreted, and their equiva lence is established. The main purpose of this paper is then the demonstrat ion that the magnetic images method is applicable for the study of simplifi ed synchronous machines. The interest of the magnetic images use in compari son with the variable separation method is shown.