Analysis and modeling of tooth-tip leakage fluxes in a radial-flux dual-stator machine with diametrically magnetized cylindrical permanent magnets

Abstract

Tooth-tip Leakage flux (TLF) has a major effect on the prediction of air-gap flux distribution and electromagnetic torque in the permanent magnet (PM) machines. Therefore, deriving a model for TLF is necessary for machine design and optimization. Accurate modeling of TLF can lead to fast and precise solutions, which ease the analysis of electromagnetic devices. It also provides the opportunity to increase torque density by more efficient utilization of PM's volume and prevent saturation in machine optimization. This paper presents a method for modeling and analyzing TLFs in a radial-flux dual-stator permanent magnet (DSPM) machine with diametrically magnetized cylindrical permanent magnets (DMCPM) in series and parallel magnetic circuit structures. In this model, some expressions in terms of machine dimensions are derived for the TLF analysis. Finite element method (FEM) is applied to validate the proposed model. Results indicate that the maximum error between the proposed model and FEM is insignificant (less than 6%). Finally, by a prototyped machine the validity of the proposed model was investigated with the experimental tests.