Calculation Model of Parasitic Capacitance for High-Frequency Inductors and Transformers

With high power density and high-frequency power electronics technologies, parasitic capacitances of inductors and transformers have been widely discussed, in which parasitic capacitance may lead to electromagnetic interference (EMI) and efficiency performance degradation. Therefore, it is significant to analyze and model the parasitic capacitance of the inductors and transformers. This paper proposes a new parasitic capacitance calculated model of multilayer windings inductors and transformers. Based on the electromagnetic field theory, it can fully consider the edge effect of multilayer inductor windings, including the edge effect between adjacent and non-adjacent layers. Finally, the accuracy of the model is validated by simulation and experiment. Compared with the traditional parasitic capacitance calculated method, the proposed model can calculate the parasitic capacitance more accurately, and the maximum error between calculations and simulations is less than 8%.