Core loss estimation of SPMSM based on field reconstruction method

Traditional core loss estimation is based on the Steinmetz Equation subject to a sinusoidal excitation. The core losses are segregated into three parts: hysteresis loss, eddy current loss and extra loss. The estimation is based on the information of maximum flux density and fundamental frequency and thereby neglecting the effects of harmonics which results in low accuracy. In order to consider the loss caused by harmonics, a field reconstruction method (FRM) is proposed to reconstruct the field density in the laminations. Fast Fourier Transformation (FFT) is applied to obtain the harmonic components of the flux density to calculate the core loss. To verify the validity of the proposed method, both FEA simulation and experiments based on a surface-mounted permanent magnet synchronous machine (SPMSM) are conducted to calculate and measure the core loss. The comparison of core loss results obtained with different methods shows that FRM is both effective and time saving in determining the core loss of a machine.