Abstract-Electromagnetic interferences are potentially very complex signals formed by the superposition of transient (broadband) and continuous wave (narrowband) components with significant randomness in both amplitude and phase. Decomposing the electromagnetic interference measured in the time domain into a set of intrinsic mode functions is useful to gain insights of the process that generates the interference. Evaluating the intrinsic mode functions contributes to improving the measurement capabilities of the time-domain electromagnetic emissions measurement systems based on the general-purpose oscilloscopes. In this paper, a combination of techniques that includes empirical mode decomposition and transient mode decomposition is used to separate the main components of complex electromagnetic disturbances. This approach requires no prior information on the spectral content of the measured EMI and it does not perform a domain transformation. Examples of electromagnetic interference decomposition verify the effectiveness and the accuracy of the proposed approach. Finally, a discussion on the advantages, practical applications, limitations, and drawbacks of the described techniques is addressed.Index Terms-Digital signal processing, electromagnetic compatibility, electromagnetic interference, electromagnetic measurements, time-domain analysis.

Abstract-It is difficult to properly evaluate the electromagnetic disturbances generated by large fixed installations because of, i.e., the background noise, unsteady emissions and transient interferences. Those challenging EMC issues have been recently studied in European research projects on improved test methods in industrial environments. In order to overcome traditional in-situ EMI measurement troubles, a novel time-domain methodology is proposed and used in a real fixed installation with large machinery. Firstly, a comparison between the developed measurement system, using an oscilloscope, and an EMI receiver is done in some test-cases for validation purposes. After verifying the accuracy of the measurements, we proceed with the measurement campaign applying the full time-domain methodology. The main benefits of employing the time-domain system are emphasised through the results. It was observed that the some remarkable advantages of the time-domain approach are: triggering by disturbance events, extremely reduce the capturing time, identify on real time the worst emissions modes of the EUT, avoid changes at the background noise and perform simultaneous multichannel synchronous measurements.

This article presents a time-domain waveform model developed to characterize pulsed, nonlinear, current waveforms resulting in electromagnetic interference on static energy meters. The waveform model is calculated by fitting the sampled waveform data into a linear piece-wise function through a process that involves applying algorithms of pulse extraction, change-point detection, and redundancy elimination. The model is applied to data from laboratory experiments that have indicated critical current waveforms resulting in electromagnetic interference problems with static meters. Afterwards, the parameters of the modeled waveforms are calculated in order to correlate them to metering errors. The most relevant parameters that are correlated to significant errors are the maximum slope, crest factor, pulse duration, and charge. The waveform model provides an accurate description of the complex nonlinear waveforms through simplified analytical expressions that reproduce the significant features of the interfering waveforms. This waveform modeling approach could be used to standardize the artificial test signals that are representative of realistic devices and scenarios.

Abstract-The increased use of carbon-fiber composites in Unmanned Aerial Vehicles is a challenge for their EMC assessment by numerical solvers. For accurate and reliable simulations, numerical procedures should be tested not only for individual components, but also within the framework of complete systems. With this aim, this paper presents a benchmark test case based on experimental measurements coming from direct-current injection tests in the SIVA unmanned air vehicle, reproduced by a numerical Finite-Difference-Time-Domain solver that employs a new subgridding scheme to treat lossy composite thin panels. Validation was undertaken by applying the Feature Selective Validation method, which quantifies the agreement between experimental and numerical data.

Abstract-An alternative approach for assessing the conformity of electromagnetic interference measuring receivers with respect to the baseline CISPR 16-1-1 requirements is proposed. The method's core is based on the generation of digitally synthesized complex waveforms comprising multisine excitation signals and modulated pulses. The superposition of multiple narrowband reference signals populating the standard frequency bands allows for a single-stage evaluation of the receiver's voltage accuracy and frequency selectivity. Moreover, characterizing the response of the weighting detectors using modulated pulses is more repeatable and less restrictive than the conventional approach. This methodology significantly reduces the amount of time required to complete the verification of the receiver's baseline magnitudes, because time-domain measurements enable a broadband assessment while the typical calibration methodology follows the time-consuming narrow band frequency sweep scheme. Since the reference signals are generated using arbitrary waveform generators, they can be easily reproduced from a standard numerical vector. For different test receivers, the results of such assessment are presented in the 9 kHz-1 GHz frequency range. Finally, a discussion on the measurement uncertainty of this methodology for assessing measuring receivers is given.

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Abstract-This paper presents a measurement system intended to be used to assets the radiated electromagnetic interference (EMI) in both time and frequency domains. In order to keep the measurement setup as accessible and practical as possible, the direct measurements are recorded with a general purpose digital oscilloscope and processed with a commonly available personal computer. The measurement system was validated for radiated emissions testing using well-known, controlled transient and continuous signals emulating typical interferences. The results are in satisfactory agreement with those provided by a conventional EMI receiver for different types of detectors. The proposed approach shows that, currently, it is possible to implement a timesaving, accurate and generally inexpensive time domain measurement system for radiated emissions that is capable to overcome the limitations of the superheterodyne EMI receivers regarding the measurement of discontinuous electromagnetic disturbances and also able to provide additional enhanced features to evaluate and troubleshoot EMI problems.

For assessing the underlying problem behind the static meter misreadings, a measurement technique must be developed for characterizing the currents that static meters are usually exposed to. In previous studies it was shown that misreadings of the static meters occur when impulsive currents are drawn from the net, even with standalone commercial off the shelf equipment. Time domain electromagnetic interference (EMI) measurements create a novel opportunity for analyzing these noisy waveforms and identifying their fundamental parameters. The next step is extending this measurement approach to on-site scenarios in which these kind of waveforms coexist in superposition with other components that are properly measured by the static meter when they occur alone. This especially holds for up and coming technologies like electric vehicle (EV) charging stations. The characterization is intended in the future for describing realistic waveforms that can be used as new standardized type-testing signals, which will be employed to produce novel standards. Time Domain Electromagnetic Interference Measurement and Post-processing System (TEMPS) software is used in conjunction with a low cost baseband digitizer to measure the waveforms of EV chargers on four different lines, that is the three phases (L1, L2, and L3) and the neutral line (N) simultaneously. To distinguish the impulsive nature of the waveforms a statistical approach is performed in the form of an amplitude probability distribution (APD) diagram. Furthermore the multichannel capability of the low cost digitizer is utilized to achieve a frequency range extension by using two probes simultaneously with different frequency ranges.