Christian Vollaire

• PhD
• Professor (Full) at École Centrale de Lyon

La propulsion électrique des aéronefs pousse à reconsidérer les marges en compatibilité électromagnétique, les règles d'installation et les standards permettant la qualification de l'avionique. La considération du réel effet physique du mode différentiel dans les standards ED-14G/DO-160G permettrait une relaxation du requis des émissions conduites...

In this paper, the scale reduction method is applied to an induction power transfer (IPT) system for electric vehicle charging for its rapid and low cost prototyping. In addition, a co-simulation method is proposed which is based on the coupling between a circuit analysis and a finite element (FE) analysis. Then, it is proposed to combine the scale...

Fast and very fast transient overvoltages generally appear during switching operations within electrical substations. The oscillatory nature of such phenomena with frequencies that can reach several tens of megahertz tends to degrade the lifetime of high voltage equipment such as bushings and transformers, inducing partial discharges activity or br...

High-voltage direct current (HVDC) links are starting to become widely implemented thanks to their interesting advantages such as reduced operation losses, the absence of reactive power, which allows energy transport via underground cables over long distances, and improved power control. The latter advantage is very essential for renewable energy r...

This work proposes a circuit model to calculate the current along printed coils used in resonant wireless power transmission systems. The proposed formulation is based on the Neumann formula for calculating the mutual inductance between coils, and due to the generality of this approach, it can be applied to more complex structures such as metasurfa...

High Voltage Direct Current (HVDC) links make it possible to transmit energy for long distances with lower losses. The development of more reliable insulation systems for HVDC components cannot be achieved without understanding the mechanisms of discharge inception and propagation, not only under HVDC constraints, but also under particular conditio...

This paper proposes an optimization approach for an automatic buck converter printed circuit board (PCB) design regarding electromagnetic compatibility (EMC) constraints. The proposed solution is based on the combination of a genetic algorithm (GA) and a Dijkstra algorithm to generate the different PCB layout designs. Afterwards, a numerical modeli...

The system capable of harvesting RF energy from the environment through an antenna and converting it into direct current energy to deliver to a load is known as rectenna. The rectifier circuit is an important part of the rectenna and its modeling is arduous since it employs a non-linear device working at extremely low power levels. In addition, the...

Generally, most of the electronic equipments need a metallic enclosure in order to mechanically protect and electrically shield the interior printed circuit boards (PCBs) and subsystems. But in practical situations, the apertures or slots of various forms are essential parts of the shielding enclosure for thermal dissipation, CD-ROMs, connectors, I...

In this paper, a method to model a passive UHF RFID system is presented and a practical application on PW (Pulse Wave) mode is described. Two levels of simulation are performed. A system level simulation (circuit model) including transmitter, modeled channel and receiver is developed using ANSYS Designer and interfaced with Matlab. And a physical-l...

We studied the harmonic magnetodynamic behavior (without free space wave propagation) of a resonant surface metamaterial, made of many identical and regularly arranged LC cells. The circuit model gives the exact solution, but it is not numerically efficient for simulating very large structures (e.g., 1000 × 1000 cells giving 10 <sup xmlns:mml="http...

Electromagnetic interference (EMI) filters design is a rather difficult task where engineers have to choose adequate magnetic materials, design the magnetic circuit and choose the size and number of turns. The final design must achieve the attenuation requirements (constraints) and has to be as compact as possible (goal). Alternating current (AC) a...

This paper presents a discrete conducted electromagnetic (EM) interference filter optimization procedure, based on a genetic algorithms. A macromodeling technique taking into account the load impedance, the source emissions and the filter parasitic components, including the filter layout, is used to obtain an accurate solution for the optimization...

A novel rectifying circuit topology is proposed for converting electromagnetic pulse waves (PWs), that are collected by a wideband antenna, into dc voltage. The typical incident signal considered in this paper consists of 10-ns pulses modulated around 2.4 GHz with a repetition period of 100 ns. The proposed rectifying circuit topology comprises a d...

This paper presents the study of conducted electromagnetic interference (EMI) currents flowing through the power cables of a DC-DC converter system and its correlation with the near field radiated from these cables. The radiated emission measurement contains a common mode (CM) and a differential mode (DM), and accurate separation of the radiated em...

This paper presents a new method to compute upper and lower bounds of any voltage or current of an arbitrary linear electric circuit model with uncertain parameters. The bounds are in the frequency domain, and when compared to a previously proposed method, this novel approach provides a higher level of guarantee. The reason is that the bounds are n...

This paper presents the study of conducted and radiated emissions due to common-mode (CM) currents flowing through the power cables of a DC–DC converter system. In order to predict the conducted electromagnetic interferences (EMI) emissions, a model of power converter system is presented. The finite-difference time-domain method (FDTD) is used for...

In this paper, the interpolation functions behavior of the natural element method (NEM) and the finite element method (FEM) are compared. It is discussed how the unknown in both methods affects the stiffness matrix and contributes to NEM better accuracy. The visibility criterion and the constrained NEM are also addressed, and a pseudoalgorithm is p...

The use of a fixed forward power as obtained during the calibration phase in a bulk current injection test, without monitoring the current, may cause damage on the equipment under test (EUT) with low impedances. In this paper, an accurate EUT model has been designed based on impedance investigation. This model can be used to predict the conducted s...

In the electromagnetic compatibility behavior of power electronic converters, parasitic magnetic couplings between components are one of the main causes of dysfunctions or poor filtering. These couplings may be either conducted or near-field interferences. To handle interaction problems, full knowledge of these magnetic couplings is essential. This...

This paper investigates the effect of model inaccuracies on the results of a design by optimization process applied to a SiC switching cell. The technologies used for this DC-DC converter and the requirements are briefly described, as well as the design by optimization process. Then, a sensitivity study is carried out to investigate the most influe...

In this paper the coupling of natural element method with the boundary element method (Hybrid NEM — BEM method) is proposed to solve the electromagnetic scattering problem. A dielectric cylinder is solved by the proposed approach and the results are compared with the analytical solution showing the usefulness and accuracy of the method.

In this article, we use a conversion chain to minimize standby-mode power consumption, detailing the different parts of the emitter and the receiver. The proposed technology is based on an efficient radio-frequency (RF) energy transfer and an RF-dc conversion circuit with a self-maintained switch that wakes up an electronic device [e.g., television...

This paper illustrates a global design methodology in the case of a simple switching cell, used in a DC-DC converter. The aim is to account simultaneously for all parameters and constraints involved in the design of the converter: thermal aspects, EMC filter and design of passives. Specific models are developed, validated and implemented in a dedic...

The modelization, fabrication and characterization of inductors using Molded Interconnect Device technology for multidirectional inductive proximity sensing is reported. Inductive proximity sensing allows contactless measurement of the position of electrically conductive objects. The principle of measurement relies on the use of an inductor which i...

Cet article propose une approche polyvalente utilisée pour modéliser un équipement lors d'un essai en Bulk Current Injection (BCI). Le modèle proposé est versatile, de sorte à ajuster les paramètres qui sont fréquemment changés lors de la mise en oeuvre des équipements telle que la position et la connexion de l'équipement sous test (EST) au plan de...

Predictive modelling of EMI is complex due to the large number of existing parameters and components. One of the relevant parameters is the temperature of semiconductors. This paper shows the influence of the temperature of the power module of a buck converter on the parasitic conducted emissions. An analysis of some parameters is done by simulatio...

A time reversal (TR) method is investigated for wireless power transmission in an indoor environment. Experiments performed with nanosecond pulses modulated at the frequency of 2.45 GHz reveal that the temporal and spatial focusing makes this technique valuable for applications of wireless power transmission. It is shown that the TR scheme avoids t...

The Ultra Wideband (UWB) technology is promising for data communications over short distances at high data rates. Since the antenna design is critical in the development of UWB systems, this paper proposes a new geometry for a microstrip UWB antenna. The modifications suggested are difficult to analyze because the proposed antenna is constructed us...

An original approach based on time reversal technique is studied for wireless energy transmission with electromagnetic waves. Experiments around 2.45 GHz are performed in a low-Q cavity of human size approaching real indoor environment. It is shown that, in order to increase the amplitude of the focused signals on a specific spot using time reversa...

After functional testing, equipment designed to be boarded onto an aircraft must be certified in accordance with established EMC standards. This paper is focused on section 20 of RTCA-DO160 which refers to the conducted susceptibility in aeronautics. Through a current injection probe, the RF interference is coupled on propagation paths (cables) for...

This paper deals with a new method of metamodel construction for electromagnetic compatibility (EMC) simulation of power electronic converters. The proposed method uses a compressed wavelet coefficients vector of a time-domain signal and a learning method [support vector regression (SVR)]. This can be applied for a black box approach of modeling of...

In this paper the treatment of material discontinuities in the Natural Element Method (NEM) are discussed. A visibility criterion and the constrained Voronoï diagram are presented in order to take account this difficulty. The extension of NEM, the Constrained NEM (C-NEM), is applied to solve electromagnetic problems. An electrostatic problem is pro...

In this paper the treatment of material discontinuities in the Natural Element Method (NEM) are discussed. A visibility criterion and constrained Voronoi diagram are introduced in order to take account this difficult. The extension of NEM, the so-called C-NEM, is applied to solve electromagnetic problems. An electromagnetic problem is proposed and...

Class-D audio amplifiers are switching circuits that produce serious Electromagnetic (EM) emissions and disturb the surrounding electronics. In order to reduce these emissions, electromagnetic compatibility (EMC) filters with ferrite beads are used. However, ferrite beads contain magnetic materials that have a nonlinear behavior. Thus, they have an...

Current and voltage signal must be correctly measured in order to evaluate accurately power losses and electromagnetic interferences in time domain. This paper proposes a way to compensate the measured signals using the gain of the probes and an evaluation of the Common Mode Rejection Ratio of the differential voltage probe. Deconvolution shows its...

In line with the trend toward continuous miniaturization and price reduction, it is crucial to analyze the impact of uncertainties on the performance of electrical circuits. Performance is evaluated for the worst-case scenario and in the frequency domain by computing upper and lower bounds. The purpose is not only to propose a method for the worst-...

This paper was partially supported by CNPq (Brazil) under the Grant PQ 307867 2011-0

Cover letter An autonomous flyback converter was designed for energy harvesting from Microbial Fuel Cells (MFCs). The circuit was optimized to minimize the losses and maximize the efficiency. A Maximum Power Point Tracking (MPPT) algorithm was implanted in the converter to extract the maximum power available from MFC. Discontinuous conduction mode...

In the electromagnetic compatibility (EMC) behavior of power electronic converters, magnetic parasitic couplings between components are one of the main causes of dysfunctions or bad filtering (e.g., in EMC filter). These couplings could be as conducted or near-field interferences. In order to handle interaction problems, a complete knowledge of the...

In line with the trend towards continuous miniaturization and price reduction, it is crucial to analyze the impact of uncertainties on the performance of electrical circuits. Performance is evaluated for the worst-case scenario and in the frequency domain, by computing upper and lower bounds. The purpose is not only to propose a method for the wors...

Over recent years, the interest in using inductive wireless power transmission for many applications has grown. One of the major limitations of this technology is the limited operating distance. Some recent works have suggested using synthesized materials known as metamaterials to improve the power transfer efficiency over distance. Due to their un...

p>Cet article présente une méthode de mesure précise de pertes dans un module d'électronique de puissance grâce à une méthode calorimétrique. Le module de puissance est placé sur la surface supérieure d'une colonne en aluminium. Le flux thermique, correspondant aux pertes traversant cette colonne peut être évalué en mesurant une différence de tempé...

This paper reports a 2.45 GHz, low power dual circularly polarized (DCP) and dual access rectenna. It contains two dc-recombined rectifiers and a cross-slot coupled square patch antenna fed by a microstrip line. A judicious dc recombination scheme allows to minimize the RF power imbalance between accesses caused by multipath effects and consequentl...

A discrete optimization using a genetic algorithm (GA) for electromagnetic interference (EMI) f ler design is presented in this paper. Using a macro-model in the frequency domain this approach takes into account the load impedance and the source emissions. The macro-model includes an accurate filter model that takes into account the PCB stray eleme...

The reduced switching times of silicon carbide (SiC) components compared to Si components in similar conditions are a great advantage from the point of view of efficiency, but, due to the high dv/dt and di/dt, conducted electromagnetic emissions are increased. Therefore, the availability of a method which can predict these emissions is increasingly...

Purpose – The purpose of this paper is to introduce a novel methodology for uncertainty quantification in large-scale systems. It is a non-intrusive approach based on the unscented transform (UT) but it requires far less simulations from a EM solver for certain models. Design/methodology/approach – The methodology of uncertainty propagation is car...

This paper studies the effect of ferrite beads on the audio quality of Class-D audio amplifiers. This latter is a switching circuit which creates high frequency harmonics. Generally, a filter is used at the amplifier output for the sake of electromagnetic compatibility (EMC). So often, in integrated solutions, this filter contains ferrite beads whi...

This paper presents an autonomous and highly efficient power management system for RF energy harvesting. The presented circuit contains a start-up resonant converter which guaranties self-starting from a low voltage (from 200mV) and low power (from 3μW) source. During the steady-state, an ultra-low power (from 2μW) Flyback converter operating in di...

The use of artificial organs completely implanted in the patient's body requires a transcutaneous energy transmitter (TET) design that provides more comfort and reliability to the patient, i.e., a TET as small as possible with the least increase of temperature and that meets several project requirements. The multiobjective genetic algorithm optimiz...

Transcutaneous Energy Transmitters (TETs) transfer wireless energy through an inductive link established between two pancake coils placed, respectively, outside and inside the body of a patient. The simulation of the misalignment between the coils must be performed in 3-D, e.g., with a Finite Element (FE) method. This paper introduces a homogenizat...

This paper proposes a method to study the impact of passive circuits such as filters, loads, and board layout on conducted electromagnetic emissions. The method is dedicated to power converters with N-active conductors and a ground conductor, followed by passive circuits. A sophisticated use of impedance matrices allows high-frequency current predi...

A new methodology to analyze electrical systems in the time and frequency domain containing a large number of uncertain parameters is presented. The methodology is based on screening and design of experiments to build surrogate reduced models at a well specified set of frequency values. As an example, the conducted interferences of a Power Converte...

This paper describes the design, modeling and optimization of an efficient ISM band dual patch rectenna capable of achieving more than 80% RF-to-DC conversion efficiency at low/medium power densities. The circuit is based on a full-wave rectifier, designed and optimized at 2.45 GHz with ADS software and the FDTD algorithm. The performances of the r...

This paper presents a new methodology to analyze the conducted interferences of power converters when its parameters are described by probability density functions rather than numerical values. The methodology is based on determining a set of surrogate models per frequency of the converter, which has less input and output variables, and shorter sim...

A reliable lumped parameters model for an Inductive Coupling Device (ICD) is necessary for many reasons, mainly to develop a robust device. This paper compares an analytical method, a proposed method through Finite Element Method (FEM) and two different physical measurement methods. It shows the advantage of FEM over the analytical method, especial...

This paper proposes a model based on the segmentation technique that can be used for electromagnetic interference (EMI) filter test by simulation. It is dedicated for systems with a differential output. The present approach proposes virtual measurement of the filter performance in the final application. Thus, the source emissions and the load imped...

In this article we present a new concept to minimize standby power of electronic devices. The proposed technology is based on RF energy transfer and DC conversion to wake up an electronic device (TV, home automation systems, etc.). In this work we present an integrated emitter and a receiver with suitable performances for home or industrial applica...

This article presents a resonant DC-DC converter topology suitable for ultra-low power and low voltage applications. The presented topology is dedicated to energy harvesting sources in general and especially for Radio-Frequency RF sources. Main advantage of this converter is its autonomy, i.e., it operates from low voltage levels without the need o...