Time Domain Analysis for Measuring Core Losses in Inductive Elements for Power Electronics: An Investigation Study

The article proposes a method to measure core losses in magnetic elements for medium-frequency power electronics circuits working in conditions close to those in many real industrial circuits: supplied with square-wave voltage and working in linear magnetic region. The article presents analytical considerations regarding the proposed method. The proposed method allows determining core losses in power inductor with only voltage and current measurement - no additional EMF-measuring winding is needed. The method is based on the inductor model, which allows determining losses in the core, while at the same time enables obtaining a time-domain response consistent with rectangular voltage excitation measurements. The method was tested using the real industrial inductor with a copper litz winding and low-loss core (e.g. nanocrystalline core) at various operating points.