Conference Agenda

Increasing near-field couplings due to miniaturization and increasing switching frequency due to new GaN and SiC transistor technologies pose new challenges in the EMC field. In this context, 3D FEM simulation is a valuable tool to prevent potential issues. This paper investigates 3D FEM simulation of CMCs by applying an accurate simulation methodology previously tested in single-winding inductors. The research is conducted in small-signal and room temperature conditions up to 1GHz, the highest frequency reached in the literature. To ensure the generality of the study, three cores of different materials were investigated (MnZn, NiZn and nanocrystalline). Their electromagnetic properties were extracted, and finally, how they influence the common and differential modes modeling of CMCs was studied.

Common mode chokes (CMCs) are conventional circuit elements performing several tasks, including noise suppression, hindering electromagnetic interference, providing signal integrity, and circuit protection. Much as they are widely used, their fundamental construction and description are often qualitative and lack an understanding of the underlying physical principles. We discuss the behavior of a commercial CMC based on the physical description of the superparamagnetic core and parasitic circuit elements. The results are validated using a DC bias current and an external magnetic field, which affect the magnetic properties. The behavior of the CMCs in the strongly non-linear regime is also described.

Common mode chokes (CMC) are widely used passive components to suppress conducted electromagnetic interferences. Models for such components are needed to simulate the electromagnetic compatibility behaviour of an electrical circuit. A state of the art strategy for modelling common mode chokes is the use of behavioural models. These models consist of circuits constructed of resistors, capacitors and inductances, based on the common and differential mode impedance of the CMC being modelled. Normally, the modelling strategy (network topology and value approximation) is designed for a specific type of CMC with a certain impedance characteristic. In this work, a novel approach based on a genetic algorithm is presented to generate models for any type of CMC across a broad frequency

range.

The results show that with this approach, CMC with different characteristics can be modelled very accurately in frequency ranges from as low as 40 Hz up to 1 GHz. The new strategy provides improved results compared to other strategies at low computational cost.

Electromagnetic interference (EMI) tends to be more numerous today due to the current trend in electronics. In addition, designers are becoming increasingly aware of equipment efficiency and thermal management, especially in switched-mode power supplies (SMPS). In most designs, a heatsink is used to reduce the temperature of the components. In addition, a sheet thermal interface material (TIM) is used to provide electrical insulation between the switching component and the heatsink. TIM improves the thermal conductivity too. However, the combination of heatsink and TIM is a source of EMI due to the generation of parasitic capacities. Therefore, in this study, EMI caused by common-mode (CM) currents generated when a heatsink is used to reduce the temperature of the mosfet is investigated. This study aims to evaluate a solution based on a hybrid material to reduce thermal and EMC problems. The proposed experimental solution is a combination of TIM agnd copper sheets. The study will be carried out by measuring the CM currents on a DC-DC boost converter. It will evaluate how it influences the use of the heatsink with TIM and the proposed hybrid solution.