The Composite Improved Generalized Steinmetz Equation (ciGSE): An Accurate Model Combining the Composite Waveform Hypothesis With Classical Approaches

Predicting core losses is a difficult task for designing magnetic components. Under triangular current waveforms the classical approaches work with duty cycles close to 0.5 but are inaccurate for high and low duty cycles. In this work the composite waveform hypothesis is tested, using data from the MagNet database for N87 material at 25 ºC (3312 data points). Limitations of the composite waveform hypothesis are discussed and a technique to expand the loss space is presented. The new approach based in an extended loss space is validated against the classical improved Generalized Steinmetz Equation, reducing the root mean square and 95 percentile errors by 5.85 and 6.96 times, allowing to predict core losses accurately even at high and low duty cycles. A direct correlation between the expanded loss space and the Steinmetz parameters from the improved Generalized Steinmetz Equation is proven, allowing to represent the core losses as functions of these parameters and generating the composite improved Generalized Steinmetz Equation. The proposed methodology for core loss prediction is validated making use of all data available from the MagNet database (10 materials, 4 temperatures, 59423 data points), achieving better results than the commonly used improved Generalized Steinmetz Equation.