Fast Calculation of Carrier Harmonic Loss in Permanent Magnet of IPMSM Under PWM VSI Supply Over Entire Working Range

Abstract

A method for fast calculating the high-frequency harmonic loss (HFHL) in the permanent magnet (PM) of interior PM synchronous machine under the pulsewidth modulated voltage source inverter supply is proposed. The combination of the frozen differential reluctivity tensor method and the linear frequency finite-element analysis (FEA) is proposed to investigate the relationship between the high-frequency harmonic voltages (HFHVs) in the rotor reference frame and the flux density variations in the PM, which is described quantitatively with the proposed analytical model using several dimensionless parameters. Then, the PM HFHLs are calculated analytically with the models using the flux density variations as input. The relative errors between the HFHLs calculated analytically and those obtained from the time-stepping FEA are within 15% at eight arbitrary working conditions. The proposed method can be used to calculate the PM HFHL in both two- and three-dimensional cases, which is testified with the experiment. Quadratic polynomial is used to fit the relationship between the dimensionless parameters and the fundamental currents. With the fitted polynomial and the analytical spectra of the HFHVs obtained from the double Fourier integration method, the PM HFHL map over entire working range can be calculated in one hour.