Evaluation of High Frequency Electromagnetic Behavior of Planar Inductor Designs for Resonant Circuits in Switching Power Converters

In this paper, a planar inductor based resonant circuit is designed for zero-current switching (ZCS) buck converter. In order to evaluate the actual behavior of the converter at the design stage, a numerical model of the inductor was created and implemented using the finite element (FE) analysis. Using the numerical model, a high frequency physics based circuit model was obtained for the converter's resonant circuit. The acquired physics based circuit model was used to approximate the electrical behavior of the resonant circuit. The operating condition of the half-wave ZCS buck converter was verified both numerically and experimentally. It was shown that by using the proposed high frequency model, it is possible to evaluate realistic waveforms of voltages and currents including the effects of parasitic elements. This is an essential step for studying conducted electromagnetic field emissions in power converters for the evaluation of their EMI interactions for EMC compliant designs.