Cogging Torque Calculation for IPM Having Single Layer Based on Magnetic Circuit Model

This research shows that it is possible and effective to predict the cogging torque waveform of the interior permanent magnet (IPM) machine using only an analytical model. Based on the proposed virtual permanent magnet (PM) concept, IPM can be considered as surface PM having zero height and unit relative permeability, and then it is used for calculating the cogging torque with conventional technique. Among the evaluation methods for cogging torque, lateral force method, which is based on lateral force acting on stator teeth, is selected. For the validation of proposed concept, finite element analysis is used. From the analysis results, it is shown that our new proposed concept presents good performance in terms of optimal position of peak cogging torque, cogging torque waveform, and the peak value. Therefore, the proposed concept can be useful in design of IPM requiring several computation processes.