Bertrand Revol

Design of a Hybrid Integrated EMC Filter for a DC–DC Power Converter

This study focuses on the design and the realization of an integrated EMI filter embedded in an aircraft power supply. The first part of the study is dedicated to the modeling of the dc-dc power, based on a “black box” representation: the converter is represented by an association of sources and impedances that reflect its external EMI behavior. This initial step enables us to define the electrical structure of the filter and the component values; a hybrid solution (active plus passive) can be effective for optimal filtering while minimizing the size and mass. The second part of the study is devoted to its realization, based on the integration of capacitive and inductive components inside a printed circuit board structure. This technology is named hybrid integration. Some technological difficulties are highlighted regarding the geometry of the components and their manufacture using this technology. Finally, filter architecture is proposed and a functional prototype is realized. Experiments show that significant gains in volume are achieved while compliance with the DO 160 standard (aeronautics) is obtained.

Common-Mode Modeling of the Association of

The reliability of electronic systems is a major constraint depending on electromagnetic interference levels. Vehicle manufacturers are clearly concerned by electromagnetic compatibility studies and, especially, for electrical drive systems in which embedded power electronics is used and must, thus, be correctly designed. A global synthesis of common-mode disturbances of such equipment is pointed out in this paper and a generic model of a complex power-electronic device is presented and applied to a motor-drive system.

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Design of static converters circuits and virtual prototyping of power electronics systems requires the use of heavy semiconductors components models, with a large number of parameters whose exact knowledge often requires several delicate experimental measurements and heavy optimisations procedures. This paper presents a sensitivity survey that permits to determine which parameters of the SPICE3 MOSFET model are applicable for the EMC analysis with the goal to reduce the number of measurements to carry out at the phase of parameters extraction.

-Switching Cells: Application to an Electric-Vehicle-Drive System

Magnetic components are widely used in power electronics and are the main cause of electromagnetic couplings. Among them, coils with ferromagnetic cores belong to the class of components that are used the most. However the behavior in terms of radiation and coupling to the environment of these components is not widely explored. This paper defines a more accurate model for coils with toroidal ferrite cores in order to get a better understanding of the coupling they created. Then the effects of the winding layout around a toroidal core are first discussed. It is found that the winding topology is the major parameter controlling both the radiated field pattern and its magnitude. A measurement bench has then been developed to validate the hypothesis made. Finally, numerical and analytic models have been elaborated to predict radiated fields from magnetic components.

Relevant parameters of SPICE3 MOSFET model for EMC analysis

In order to efficiently reduce EMI emissions, especially common mode (CM) conducted noise emissions that are the most disturbing in any adjustable-speed drive systems, behaviour understanding and propagation path knowing of parasitic currents in the system are indispensable. In this paper, a simple CM disturbances modelling is proposed to estimate or calculate the CM noise currents. The modelling principle is based on specific experimental characterizations and on the modelling of the complete CM circuit considered as a chain of quadripolar matrices. Each part of the system is represented by a two-port network associated in cascade by using transfer matrix [T]. The comparison between calculations and experiments in an adjustable-speed drive system confirms effectively the validity of the proposed approach. Parametric studies carried out herein using this valid model will show in which way CM currents could be reduced or eliminated in a considered existing system.

Accurate Modeling of Radiated Electromagnetic Field by a Coil With a Toroidal Ferromagnetic Core

The presence of numerous power electronics converters on embedded networks, originates EMC issues. EMC modeling of power electronic converters is tricky due to modeling complexity. Indeed, on one side, EMC study needs the finest characterization of each element, thus, only a few numbers of converters plugged to the network can be described. On the other hand, a conventional network approach, representing the converters on a pure functional point of view, does not allow such analysis of each element. Therefore “black box” or “grey box” approaches, representing the global behavior of the converters, are a good compromise between those two antagonistic needs. This article aims to sum-up characteristics of different EMC models in order to justify the choice of terminated approach. Then, all identification issues will be addressed: Theoretical difficulties such as the physical meaning of the identified impedances; Practical difficulties like attenuated conditions sizing and measurement protocol.

Measurements and Simulation of Common Mode Conducted Noise Emissions in Adjustable-Speed AC Drive Systems

In this paper, a configuration for a Neel effect ac-dc current sensor designed with second harmonic sensing in view is proposed. This configuration relies on the use of two toroidal superparamagnetic cores wound in opposite direction with respect to each other and connected in series. An analytical model is developed, which shows that the component of the output signal at the excitation frequency, which is useless, should be removed provided that the windings are symmetrical. The latter principle is validated experimentally and a prototype device is characterized for different excitation conditions. Open loop dc and ac current measurements are carried out over the [-110 A, 110 A] range.

EMC models of power electronics converters for network analysis

Toward the aim of advanced integration in power electronic, the properties of Multicell interleaved converters are of prime interest. Among these properties, the EMC behavior is interesting and the dynamic performances are excellent. However their implementation requires the monitoring and balancing of intercell currents. On one hand, the converter control must ensure a satisfying balanced distribution of currents among switching cells outputs, so that magnetic components are used optimally. On the other hand, this control must also ensure the regulation loop of the output current. To achieve these goals, we decided to work on a direct matrix model, which allows to highlight the fast eigenmode related to the power (common mode) and the slow magnetizing eigenmodes (differential modes). The synthesis of the control and the calculus of corrector parameters are performed using inversion of this direct model. A digital control based on this method has been implemented, and the measurement results that we present confirm its efficiency on current balancing.

Neel Effect Toroidal Current Sensor

Proven by both academia and industry, silicon carbide (SiC) semiconductors become ready to replace their silicon (Si) counterparts in power electronics. However, since they operate under high electrical constraints and at high switching frequencies, electromagnetic interference (EMI) level becomes higher. As a consequence, developing new modeling methods that require low time consumption, able to reconstruct accurately the transient behavior of a switching cell becomes a necessity. In this paper, a new modeling method based on configurable partial transfer functions (CPTFs) is proposed. This method allows an ultrafast accurate reconstruction of transient waveforms and an accurate EMI sources identification in both temporal and frequency domains. The parameters used to fill these CPTFs are identified by measurement or directly from the manufacturer technical files. The obtained results are verified by comparing simulations with experimental switching waveforms.

Control for the currents balancing of a multicell interleaved converter with ICT

This paper proposes a method to synthesize a full wave control applied to a multilevel modular converter (MMC). This method guarantees the output waveform and the balancing of the capacitors. Numerical simulations and experiments are used to check the validity of the approach.