High-power DC-3AC converters for electric aviation generate conducted emissions from fast dV/dt and dI/dt, challenging DO-160. Fixed-point Thevenin models lack dynamic range coverage. We propose interpolating Thevenin equivalents from spectral terminal current measurements at extreme power points, using ONERA's Mini TROPHEA bench. Results show linear harmonic amplitude correlations, validated with < 6 dB error below 20 MHz for crosstalk configuration and up to 400 MHz for common mode currents. This black-box method extends to predictive multi-point EMC modeling, preserving confidentiality and aiding aerospace optimization.

This paper presents a large experimental challenging work to understand and prevent the real physical conducted disturbances and noises issued from actual power chips devices used in mobile electric systems. A canonical Power PCB is realized to support parametrical and comparative characterizations with different technology of power semiconductors and their electrical and physical environment. First, a complete experimental flow for differential and common modes conducted disturbances characterization at circuit and board levels is presented. Then, we complete parametric studies with temperature impacts on these electromagnetic emissions. That leads to the discussion of new cases of electromagnetic emissions and couplings with electronic devices used to control power and energy, especially in autonomous and embedded systems such as electrical airplanes.

This paper presents a synthetic state of challenging work to understand and prevent the real physical and electromagnetic noises and radiation issued from actual power chips devices used in mobile electric systems. A canonical Power PCB is realized to support comparative characterizations and modeling ways with different technology of power semiconductors. First, a global modeling procedure, mixing analytical and behavioral data and parameter definitions, is presented, so to validate a realistic simulation of electromagnetic disturbances. Then, we present experimental studies of temperature impacts on these electromagnetic emissions. That leads to the discussion of new cases of EM emissions and couplings with electronic devices used to control power and energy, especially in transportation and embedded systems.

This article describes a Thevenin black-box modeling method for a converter in the context of a power architecture used for aeronautical applications. It focuses on a non-intrusive procedure based on frequency-domain measurement of the elementary and common-mode currents across the converter, as well as measurement of the impedances of the power architecture equipment. It demonstrates the use of a minimization algorithm to reconstruct the phases of elementary currents not directly accessible by measurement, and the validity of this method. Finally, the model is validated by comparing simulation and measurement, in particular the unterminated aspect of the model

The development of reliable electrical machines must consider the ageing phenomena of winding insulation system. When subjected to PWM-like voltages, the winding insulation degradation may be accelerated through partial discharges (PD). The use of wide band gap power electronics components implies to consider these degradations even for low-voltage applications. To assess the electrical insulation health state of the winding, PD detection can be performed. The aim of this study is to investigate the PD inception in polyimide-epoxy samples designed with an enclosed cavity. A detection system based on an electric field antenna combined with a spectrum analyzer is developed for this purpose. An impulse winding tester and a Silicon Carbide-based power generator are both used to carry out this PD study. Switching frequencies up to 80 kHz are analyzed in terms of PD inception voltage.

Dielectric material ageing is one of the main issues which induces electrical machine failure. This ageing is most generally induced by thermal and electrical stresses, oxidation, or a combination of these different effects. Ultra-High Frequency (300 MHz - 3 GHz) characterization may be a promising method for the insulation ageing assessment, by monitoring the evolution of the dielectric properties in this frequency band. This characterization can be performed using electromagnetic sensors. Therefore, the main topic of this study focuses on the relative permittivity evolution of epoxy resin samples exposed to thermo-oxidative stress measured by a microstrip ring resonator. The first step is to determine if the sensitivity of this sensor is sufficient to identify a change in the dielectric properties of the resin samples. In order to correlate these potential changes induced by ageing phenomena, Fouriertransform infrared spectroscopy and mass loss measurements are also performed.

CEA CESTA center is developing a pulsed power generator able to produce up to three consecutive high-voltage pulses on induction cells to investigate pulsed power for multi-pulse X-ray Flash Radiography. Due to the very short delay between pulses, dispersions created by the first pulses degrade the voltage plateaus of the following ones, thus calling into question the performances of the whole multi-beam linear accelerator. Our aim is to investigate the benefit of the semiconductor technology to improve the second and third pulses of the burst. Associating semiconductors in series-parallel matrix are increasingly being considered for high pulsed power applications but to be efficient, they must meet at some characteristics such as high switching speeds, low overshoot, etc. To guarantee compact systems, SiC MOSFETs are often the preferred choice among several technologies. To increase their characteristics, it is necessary to associate several of the same type devices which will generate undesirable phenomena that can damage the components and the system itself. This paper presents a study carried out to learn how to characterize and identify which intrinsic characteristics of the component are to be considered during such associations when it is used under strong voltage, high current, dV/dt and dI/dt. This will help us in the choice of technology, package that it will be used according to the application sought.

The strong development of solid-state power sources offers numerous benefits (such as higher operating frequencies and reduced switching times and power losses), but contributes inherently to the extended range of electromagnetic interferences (EMI). As these systems are associated with a set of embedded monitoring devices using low amplitude signals, it becomes necessary to consider new critical cases of electromagnetic (EM) immunity correlated to such environments. The most common solution against aggressive radiated EMI is the metallic enclosure, which brings a strong shielding effectiveness (SE), but is it always the best compromise? Our study in this paper is focused on the SE of multilayer designs and is therefore intended to optimize the enclosures’ compactness for board level shielding (BLS) on printed circuit boards (PCB). First, results are presented, based on metallic multilayer shielding theory and parametric numerical studies in the intentional electromagnetic interferences (IEMI) frequency range, from 0.2 to 5 GHz. Then, a complete 3D EM co-simulation model using the microwave and design modules of CST Studio Suite (which includes the subject, the EMI radiating source, and the multilayer shielding) is proposed, with emphasis on the pertinent choices regarding layers width and their arrangement for compact EM shielding and immunity optimization.

These last years have seen the growing interest of electrical engineering community for wide band gap semiconductors (Silicon Carbide, but also Gallium Nitride more recently) since they allow much more compact and efficient designs due to their faster operating frequencies.