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Purpose – The purpose of this paper is to discuss the performance of a proposed machine design for an in-wheel motor with the required torque-speed characteristic. Design/methodology/approach – Calculation of the winding factor of the machine with the star of slots theory is performed first. The field weakening capability of the machine is investigated and the operating speed range is determined. The tooth contour modeling method for calculating the performance of the machine with a limited number of elements is introduced. The method is used to construct two models of different complexity and the results obtained with the models are compared with the results obtained by finite element models. Findings – The 14 pole 12 slot in-wheel PMSM discussed in this paper is able to meet the stringent performance requirements. The results obtained with the tooth contour models show good agreement with the results obtained with finite element models despite the limited number of elements. Increasing the number of elements in the model allows for modeling of armature reaction and increases the accuracy of the model. Research limitations/implications – This work can be continued with investigating the possibilities to model the armature reaction more accurately. Originality/value – This paper proposes a modeling method which accurately describes the performance of a PMSM with limited number of elements. With this method, the calculation procedure can be easily used for optimization of the machine design. [ABSTRACT FROM AUTHOR]

Purpose – Transient torque calculations of the parallel flux switching machines, both cogging and electromagnetic, require a long simulation time for transient analyses. This paper seeks to present an optimization method for the accurate but time consuming transient models. Design/methodology/approach – A superposition principle is used to optimize the simulation time of the machine model. Finite element method (FEM) is chosen as the example machine model, since it is widely used among researchers for its accuracy. The machine geometry is simplified by reducing the number of rotor teeth, because these parts are re-meshed with each transient step. Torque results are compared to the full machine model to find the best representation. Findings – Among compared simplified machine geometries, the two teeth model gives the most accurate results. Research limitations/implications – The superposition method requires a modelling method such as FEM. The method offers a geometrical simplification of the machine, not a complete model. Practical implications – Parallel flux switching machines should be considered as promising candidates for hybrid and electrical truck applications due to their high power density. For these kind of applications, a fast torque estimation tool helps greatly in investigating noise related mechanical problems, which have a direct effect in passenger comfort. Originality/value – Whereas researchers in this area mainly focus on accurate but time-consuming modeling of this nonlinear machine, this research shows an optimization of these methods to speed-up them. The proposed optimization method can be integrated with any analytical or numerical machine model. [ABSTRACT FROM AUTHOR]