Core Loss Evaluation in Powder Cores: A Comparative Comparison between Electrical and Calorimetric Methods

Utilizing powder cores in many power electronics applications have gained interest due to the attractive magnetic properties of powder core materials. For instance, powder cores have soft saturation characteristics and high saturation flux density compared to gapped ferrites. However, due to their low relative-permeability and the low loss characteristics, a precise measurement of the core losses is very difficult to be obtained. One of the common approaches to measure core losses is by measuring the electrical signals of the winding terminals, we hereafter refer it as "electrical methods". Another alternative approach is calorimetric methods, which rely on measuring the core temperature rise. Nonetheless, these methods may have huge measurement error in case of powder cores. This paper evaluates the accuracy of measuring core losses in powder cores, and a comparison between the electrical and calorimetrical methods is presented. Along with the theoretical discussion, simulation and experimental tests are conducted.