Fast Calculation of High Frequency Air Gap Flux Density Harmonics by Frozen Permeability Method in Electrical Machines

This paper introduces a fast calculation of high frequency air gap flux density harmonics in electrical machines, using the frozen permeability technique. This approach can rapidly and efficiently evaluate the amplitude of harmonic flux density components due to PWM in electrical machines. This method combines electrical equivalent circuits and the finite element approach, furthermore operating conditions and magnetic saturation can be taken into account. A comparison with transient FEM simulation is performed to validate the reliability of this fast calculation. The findings confirm that the fast calculation method can provide accurate results and truly reduce computation time from a few hours to minutes.