High-Frequency Behavioral Ring Core Inductor Model

The switching of the power semiconductors in static converters is the main source of electromagnetic interferences (EMI). To meet with electromagnetic compatibility standards, it is necessary to reduce the level of the conducted emissions. This reduction can be achieved by different techniques including the EMI filters whose design is mainly based on the use of ring core inductors. This element is a key point for designing efficient EMI filters, requiring then accurate inductor high-frequency (HF) models. Therefore, this paper deals with the development of an HF behavioral model of inductors, based on electrical equivalent circuit, for an implementation in circuit simulation software. The aim is to provide a robust and adjustable model under small-signal operating conditions for frequencies up to 100 MHz. The proposed model considers the frequency-dependent properties of the magnetic core material and also includes the parameterization of the electrical equivalent circuit elements with the number of winding turns and dimension of the magnetic core. Simulations results using the obtained inductor model are validated by impedance measurements with two types of magnetic materials: ferrite and nanocrystalline.