A New Core Loss Model for Rectangular AC Voltages

For most power converters, the voltage waveforms on the inductors or transformers are rectangular or composed of rectangular shapes. The waveform will have an impact on the value of the core loss. An accurate model is required in order to predict the core loss under such excitations and assist the design trade-offs. The most popular core loss models now are the modified Steinmetz equation (MSE), and the improved generalized Steinmetz equation (iGSE). However, the measurement data shows these models don't give accurate prediction under certain waveforms. A new model named rectangular extension of Steinmetz equation (RESE) is proposed to improve the accuracy for the core loss under rectangular AC voltages by employing a parameter., which is strongly related to material and frequency. Several ferrite materials are characterized and modeled with this new parameter for rectangular voltage excitation.