Iron loss calculation under PWM inverter switching for SiFe steel materials

This paper presents an iron loss calculation method for SiFe steel material under high-frequency current ripple due to PWM switching. The PWM switching produces dynamic minor loops on the BH plane, which cause iron loss. In this study, the improved Bertotti's physical model is used for iron loss calculation for dynamic minor loops in SiFe steel material. The calculated iron loss values are compared with the measured iron loss values. The model predicts the iron loss within an acceptable error. However, calculation errors are found when comparing the iron loss value for each dynamic minor loop. The reason for the calculation errors is that the measured iron loss varies if the flux density bias is different, even if the DC-bias has the same value. The calculation error occurs not only in the improved Bertotti's physical model but also in other methods such as improved Steinmetz equation because these methods do not take into account the flux density bias and/or the DC-bias characteristic.