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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 paper is an overview of the work on near magnetic field interference undertaken in the last 15 years by the International Maxwell Laboratory. This paper details a predictive method that accurately and efficiently calculates near magnetic field coupling between two sources. The method uses near-field multipolar expansion in spherical harmonics of electromagnetic sources to determine close magnetic coupling between two sources from their equivalent models. This paper also shows how theoretical developments of large loop antennas have evolved from the van Veen antenna, a model with only two degrees of freedom, to a more complex model in terms of degrees, order, and types of harmonics. In parallel, it describes developments in the measurement method that provides input to the theoretical model. To illustrate how the research has evolved, we discuss coupling between two complex sources to assess the accuracy of this predictive method. [ABSTRACT FROM PUBLISHER]

A terminal model is a common method to create equivalent models of dc–dc converters in order to predict conducted emissions. In this paper, a characterization method for converters with stochastic behavior is presented. The averaged and maximized spectra of the measured voltages and currents are used to create the model. The phase information is obtained using a dedicated reference channel. After the equivalent source was determined, the actual induced noise voltage at the test load was compared to that predicted by the model with the averaged and maximized spectra to estimate its accuracy. The results indicate that the agreement with the direct measurement is between 10 dB and 100 MHz. [ABSTRACT FROM AUTHOR]

As the key devices of an HVDC transmission system, converter valves should bear different forms of overvoltage. Additionally, the wideband frequency electromagnetic noises caused by the switching of thyristor may impact the normal operation of the communication and control systems in an HVDC converter substation. Consequently, it is of great significance to build the model that is suitable for wide frequency range for the key components of converter valve system. Based on the elementary wideband model, the integrated wideband model is proposed and the estimation method for corresponding parameters is also addressed for different kinds of components in this paper. The theoretical analysis and simulation results show that the integrated wideband model has high accuracy and simplicity; it also can provide the results with rigorous passivity and specific physical meaning. As for the application, the proposed method is used to model the key components of an HVDC converter valve and proved to be correct and effective. [ABSTRACT FROM AUTHOR]

The objective of this paper is to present a methodology for identifying the current flow in the capacitors of a multiphase buck converter by synchronously measuring the capacitor currents. A multiphase buck converter uses multiple parallel buck converters with different switching times to source a large amount of current. Currents in the primary capacitors of a multiphase buck converter are drawn by all phases of the converter; however, the phases switch asynchronously. Synchronizing to the switching of a specific phase reveals how the current from that phase is distributed among the capacitors throughout a circuit board. The proposed measurement method is illustrated by comparing an initial printed circuit board design to a new design to show the effect of better capacitor placement and the addition of a ground plane. The new design confines the phase currents to the capacitors close to the field effect transistors of the specific phase. [ABSTRACT FROM AUTHOR]

This paper presents a fractional-N phase-locked loop based spread spectrum clock generator (SSCG) using a programmable linear frequency modulator. The SSCG provides a programmable frequency deviation and modulation frequency regardless of its operating frequency. The ranges of frequency-deviation ratio and modulation frequency are 0–80% and 0–100 kHz with 610 Hz step resolution. The proposed SSCG successfully support five serial-link standards by using a single SSCG, and can be applied to various switching circuits such as class-D power amplifiers or switching power converters. The EMI reduction was measured to be 10.24–13.94 dB under 100-kHz resolution bandwidth. The proposed SSCG was fabricated using a 0.13-μm CMOS process with an active area of 0.11 mm2, while consuming an overall power of 6.28 mW at 1 GHz. [ABSTRACT FROM AUTHOR]

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 these magnetic couplings is then necessary. Our study is focused on near magnetic field's interferences. Indeed, the characterization of electromagnetic field in power electronics is still in active research. This paper details a predictive method that calculates accurately and efficiently the near magnetic field coupling between two sources. By using the near-field multipolar expansion in spherical harmonics of electromagnetic sources, the close magnetic coupling between two sources is determined from their equivalent model. It is shown that the increase in degree up to the fourth provides a more precise representation of the elements and thus a better accuracy of the near-field coupling prediction. Also, theoretical and experimental developments will be presented. The coupling between two complex sources will be considered to validate the predictive method. [ABSTRACT FROM AUTHOR]

The aim of this paper is to describe a first- approximation model that predicts the emissions radiated by an induction-machine motor drive. The proposed model can be used in the design stage of an asynchronous motor drive. A three-phase induction machine supplied by a voltage-source inverter is studied; both square-wave and pulsewidth modulations of the power converter are considered. Computer simulations are presented to prove the validity of the proposed model. The applications considered lead to numerical results that are in qualitative agreement with those calculated and/or measured by other authors. [ABSTRACT FROM AUTHOR]

A conducted EMI prediction model for an interleaved power factor correction (PFC) converter including the nonlinearity of the boost inductors is presented. The Jiles–Atherton (J–A) technique is adopted to handle the nonlinear behavior of the interleaved boost inductors. The conventional conducted EMI prediction model without including the nonlinear effect of the boost inductors tends to underestimate the true conducted EMI level. With the proposed model, conducted EMI can be predicted with higher accuracy so that the correct EMI filter can be designed to meet the required EMI regulatory limits. [ABSTRACT FROM PUBLISHER]

Deals with the broad-band modeling of a realistic electric power converter shield used in an electric vehicle. Characterization of the true radiation of a power converter; Global electric and magnetic shielding effectiveness of the converter; Radiation of typical existing apertures.

This correspondence discusses the implementation of clock slope control to reduce emissions from fully-integrated step-up dc/dc converters. The addition of clock slope control is a common technique used to reduce electromagnetic emissions normally associated with charge pumps. The clock slope control is coupled with frequency and current control voltage regulation methods. [ABSTRACT FROM AUTHOR]

The filter development process, to reduce conducted emissions, is still a nonoptimized problem within the electromagnetic interference improvement of systems. Because the filter attenuation depends on the impedance values of the device under test, numerous attempts might be necessary to find an appropriate filter element. The presented method tries to characterize arbitrary active applications within the time domain for simulation and measurement setups. The evaluated noise sources are described as V or Z matrices with additional active sources with respect to Thevenin's law. Using a transition from the time into the frequency domain, any circuitry with periodic and stable noise sources can be considered. The application of the method is demonstrated for an auto- motive buck converter in the frequency range up to 108 MHz. The characterization of the generated noise source model is verified by comparing calculated and measured noise voltages with different filter elements. [ABSTRACT FROM AUTHOR]

An improved and simplified electromagnetic interference (EMI) modeling method based on multiple slope approximation of device-switching transitions for EMI analysis of power converters is presented. The traditional noise source modeling method, which uses single slope for rise and fall transition, is studied, and the criteria for reasonable modeling in the frequency range is analyzed. The turn-on and turn-off dynamics are investigated by dividing the nonlinear transitions into several stages based on an insulated gate bipolar transistor (IGBT) behavior circuit model. Real device-switching voltage and current waveforms are approximated by piece-wise linear lines and modeled by multiple dv/dt and di/dt slopes. The predicted EMI spectra suggest that high-frequency EMI noise is modeled with an acceptable accuracy. The proposed method was verified experimentally for a dc-dc buck converter. [ABSTRACT FROM AUTHOR]

Examines the power electronic converter electromagnetic compatibility analysis through state variable approach techniques. Computation of the noise spectrum in the frequency domain for hard switching converters; Reduction of the global noise emissions; Advantages of the proposed technique.