Analytical-based investigation of consequent poles permanent magnet machine: improved air gap flux density formulation

Purpose This paper aims to an analytical investigation of a consequent poles (CP) permanent magnet machine, to enhance the accuracy of the predicted air gap flux density and thus of the machine performance. Design/methodology/approach The machine under study is obtained by the substitution of the poles machines (PMs) that corresponds to south poles, of a conventional surface PM (SPM) machine, by iron pieces of same geometry. First, the analytical model of the air gap flux density generated by a SPM topology is presented. To fit the CP concept, such model has been rearranged based on a virtual SPM machine. Then, an improved prediction of the CP machine air gap flux density is addressed by the incorporation of a south pole rotor correction function. Findings An improved prediction of the consequent pole PM machines air gap flux density is addressed by the incorporation of a south pole rotor correction function. Originality/value The paper proposes an original approach to enhance the prediction of the air gap flux density of consequent pole machines despite the different magnetic permeability of the north and south poles.