Modelling and simulation of conducted emissions in the powertrain of electric vehicles

In the general framework of intelligent transportation, the increasing use of information communication technology in full or hybrid electric vehicles requires careful assessment of electromagnetic compatibility, with specific reference to the conducted emissions (CE) generated by the inverter in a broad frequency range (10 kHz-100 MHz). To this aim, this work reports a modelling approach for the prediction of CE in electric powertrains, which is based on circuit representation of each single subsystem, that is, the battery, the inverter, the three-phase synchronous motor, and the power buses composed of shielded cables. The proposed models are able to represent both low-frequency functional aspects and high-frequency parasitic effects of paramount importance for CE analysis, and can be implemented into a Simulation-Programme-with-Integrated-Circuit-Emphasis (SPICE) solver. The proposed modelling approach is exploited to simulate virtual CE measurements according to international standard CISPR 25, and to investigate the impact of setup features, including grounding connections of shields, the propagation of CE in electrically long power buses, the operating point (power, torque, speed) of the motor-drive system

Upper bound of overvoltage peak induced in power line network above lossless ground due to radiated electromagnetic disturbances

This paper deals with the assessment of the maximal peak of the overvoltage induced in a power-line network due to the field-to-wire coupling from an external electromagnetic disturbance. A worst-case analysis is here combined with the transmission line model to find the terminal overvoltage, induce by radiated electromagnetic disturbances of constrained energy density and bandlimits. The approach was applied to canonic power line network topologies, from statistic viewpoint, it is demonstrated that dominant coupling can be ascribed to the branch containing the most twisted segments. Accordingly, efforts have been devoted to find analytical solution to overvoltage peak upper bound for the coupling-dominant zigzag branch. In this connection, both versatile implicit solution and approximated explicit expressions of the upper bound are formulated, which reveals the relations between the upper bound of zigzag branch and its segments, quantitively interpreting the effect of segment orientations and length. Finally, numerical simulations corroborate the model validity and suggest that the estimations of upper bound are sufficiently accurate for analyzing practical power line network. This proposed approach will be instructive for power system insulation coordination and protection design

Modeling of imbalance in differential lines targeted to SPICE simulation

partially_open5siIn this paper, a SPICE model representative for the mode conversion occurring in differential lines affected by imbalance either of the line cross-section and the terminal networks is developed. The model is based on the assumption of weak imbalance and allows approximate prediction of modal quantities, through separate modeling of the contributions due to line and termination imbalance by controlled sources with (possibly) frequency dependent gain. The proposed SPICE model is used to perform worst-case prediction of undesired modal voltages induced at line terminals by mode conversion.openGrassi, Flavia; Wu, Xinglong; Yang, Yuehong; Spadacini, Giordano; Pignari, Sergio A.Grassi, Flavia; Wu, Xinglong; Yang, Yuehong; Spadacini, Giordano; Pignari, SERGIO AMEDE

Numerical Electromagnetic Modeling of Chemical Plants for the Assessment of Radio Frequency Ignition Hazards

Abstract In this work, electromagnetic simulation of electrically-large chemical plants is used to investigate RF ignition hazards. The proposed analysis is aimed at refining results and procedures detailed in the European Standard CLC/TR 50427, which foresees the use of elemental antennas (loops and half-wave dipoles) for the estimation, via closed-form approximated formulas, of the RF power induced by an impinging electromagnetic field

Scattering parameters characterization of periodically nonuniform transmission lines with a perturbative technique

In this article, a novel procedure for the frequency-domain solution of nonuniform transmission lines (NUTLs) is presented. The procedure is based on a recently proposed perturbative technique, which is proven to be computationally more efficient than standard solution approaches, which are based on line subdivision into uniform cascaded sections. With respect to the original perturbation technique, the procedure proposed here offers more flexibility, as it provides a representation of the NUTL under analysis in terms of S and/or T parameters at its ports. Moreover, it retains the same prediction accuracy at the price of a slight increase in computational burden, which can be mitigated anyway through parallel computing. Furthermore, even without ad hoc (parallel) implementations, the proposed procedure outperforms other approaches to solve differential lines with partially or fully repetitive geometries. Namely, it assures accurate prediction of output quantities with reduced simulation time. This is proven by three application examples, namely, two differential trapezoidal tabbed lines (one with interdigital tabs and one with facing tabs), and a differential microstrip line with a varying common-mode (CM) impedance (as such reducing CM noise). Comparison with full-wave simulations allows assessing the prediction accuracy of the proposed procedure. Comparison with the aforementioned transmission-line-based solutions allows appreciating the enhanced computational efficiency

A Possibilistic Approach for the Prediction of the Risk of Interference between Power and Signal Lines Onboard Satellites

This work presents a hybrid random/fuzzy approach for uncertainty quantification in electromagnetic modelling, which combines probability and possibility theory in order to properly account for both aleatory and epistemic uncertainty, respectively. In particular, a typical intrasystem electromagnetic-compatibility problem in aerospace applications is considered, where some parameters are affected by fabrication tolerances or other kinds of randomness (aleatory uncertainty) and others are inherently deterministic but unknown due to human's lack of knowledge (epistemic uncertainty). Namely, a differential-signal line in a satellite is subject to crosstalk due to a nearby dc power line carrying conducted emissions generated by a dc-dc converter in a wide frequency range (up to 100 MHz). The nonideal features of the signal line (e.g., weak unbalance of terminal loads) are treated as random variables (RVs), whereas the mutual position of signal and power line is characterized by possibility theory through suitable fuzzy variables. Such a hybrid approach allows deriving a general and exhaustive description of uncertainty of the target variable of interest, that is, the differential noise voltage induced in the signal line. The obtained results are compared versus a conventional Monte Carlo simulation where all parameters are treated as RVs, and the advantages of the proposed approach (in terms of completeness and richness of information gained about sensitivity of results) are highlighted

Combined MTL-fullwave statistical approach for fast estimation of radiated immunity of spacecraft cable assemblies involving multipair bundles

In this work, a computationally-efficient modelling approach is developed to predict the electromagnetic noise induced in the terminal units of random bundles of twisted-wire pairs mounted onboard spacecraft. The proposed model combines the results of a preliminary full wave simulation, aimed at evaluating the electromagnetic field inside the space vehicle’s metallic body, with a stochastic model of a random bundle, based on multiconductor transmission line (MTL) theory. Model assessment versus measurement data obtained characterizing real wiring harness in a full-scale satellite mock-up demonstrates the large sensitivity (up to 40 decibels) of the induced noise levels to different bundle configurations, and corroborates the effectiveness of the proposed simplified modelling strategy for estimating the modal noise voltages induced in the terminal units

Methods of investigation for cardiac autonomic dysfunction in human research studies

This consensus document provides evidence‐based guidelines regarding the evaluation of diabetic cardiovascular autonomic neuropathy (CAN) for human research studies; the guidelines are the result of the work of the CAN Subcommittee of the Toronto Diabetic Neuropathy Expert Group. The subcommittee critically reviewed the limitations and strengths of the available diagnostic approaches for CAN and the need for developing new tests for autonomic function. It was concluded that the most sensitive and specific approaches currently available to evaluate CAN in clinical research are: (1) heart rate variability, (2) baroreflex sensitivity, (3) muscle sympathetic nerve activity, (4) plasma catecholamines, and (5) heart sympathetic imaging. It was also recommended that efforts should be undertaken to develop new non‐invasive and safe CAN tests to be used in clinical research, with higher sensitivity and specificity, for studying the pathophysiology of CAN and evaluating new therapeutic approaches. Copyright © 2011 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86917/1/1224_ftp.pd

SPICE behavioral modeling of RF current injection in wire bundles

In this work, a measurement-based procedure aimed at deriving a behavioral model of Bulk Current Injection (BCI) probes clamped onto multi-wire cable bundles is proposed. The procedure utilizes the measurement data obtained by mounting the probe onto the calibration jig for model-parameters extraction, and 2D electromagnetic simulations to adapt such parameters to the specific characteristics of the cable bundle under analysis. Outcome of the analysis is a behavioral model which can be easily implemented into the SPICE environment. Without loss of generality, the proposed model is here used to predict the radio-frequency noise stressing the terminal units of a two-wire harness. Model accuracy in predicting the common and differential mode voltages induced by BCI at the line terminals is assessed by EM modeling and simulation of the involved injection setup by the commercial software CST Microwave Studio

Plane-wave coupling to a twisted-wire pair above ground

A transmission-line model is developed for predicting the response of a twisted-wire pair (TWP) circuit in the presence of a ground plane, illuminated by a plane-wave electromagnetic field. The twisted pair is modeled as an ideal bifilar helix, the total coupling is separated into differential- (DM) and common-mode (CM) contributions, and closed-form expressions are derived for the equivalent induced sources. Approximate upper bounds to the terminal response of electrically long lines are obtained, and a simplified low-frequency circuit model is used to explain the mechanism of field-to-wire coupling in a TWP above ground, as well as the role of load balancing on the DM and CM electromagnetic noise induced in the terminal loads