Calculation of core loss is essential in the design of magnetic components especially in high frequency applications. Existing empirical approaches still present some limitations such as the inaccuracy and the difficulty to apply under non-sinusoidal waveforms. In particular, these methods fail to predict core loss with low duty cycle and when there is a significant change in the frequency. In addition to that, the use of different solutions of Steinmetz parameters for different frequency range can present some discontinuity problems at the boundary of each frequency interval. The main contribution of this study is to develop a new empirical method to estimate magnetic core losses under nonsinusoidal induction. The developed method is enough accurate and user-friendly to apply by designers. The effects of the frequency and the duty cycle are considered. The developed model is verified and compared with the Improved Generalized Steinmetz Equation (IGSE) and measurement data from literature with 3F3 and N67 ferrite materials.Index Terms-High frequency core loss, empirical core loss calculation method, Ferrite materials.

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Existing empirical core loss models for symmetric trapezoidal flux waveform (TzFW) still suffer some issues such as the inaccuracy and the complexity. These issues are mainly due to the lack of an accurate model of the relaxation loss generated during the offtime. This paper aims to understand the relaxation loss and develop an accurate model using the superposition technique. The developed model gives an accurate prediction of the on-time loss and the relaxation loss and shows the dependency of each on the duty cycle. The research shows that the core loss at low duty cycle is several times the core loss at full duty cycle. The developed model is verified with experimental results and compared to the Improved Steinmetz equation (ISE). The model error is reduced to lower than 15% compared to 50% of the ISE. Finally, an easy method using multiplication factors with the ISE model is given to simplify the developed model.

In this paper, the effect of the core geometry of nontoroidal magnetic cores on the magnetic loss is investigated. A frequency dependent core material-geometry loss factor is developed. This factor is function of the change in the non-toroidal core section and the Steinmetz parameter "β". In addition, the temperature effect is included in the developed loss model for wide range of frequency and magnetic flux density. The model is applied for ER core and 3C92 ferrite material. The core loss measurements are performed using a Peltier cell. The principle of operation of the Peltier cell is based on the Seebeck effect, which convert the heat flow due to the temperature difference into electric power. The calibration of the Peltier cell is validated with a resistive load and a relative error lower than 1% is achieved. The accuracy of the developed model is assessed with FEA and the experimental results. A maximum error of 10% is registered of the developed core loss model.

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