Pierre Bertholet

Calibration of UHF sensors for GIS: Comparison of different methods and testing of a calibration system based on a conical antenna

Different methods of calibrating UHF sensors for gas insulated substations (GIS) were investigated in the past. This paper compares existing calibration methods and shows their advantages and disadvantages. To overcome the known disadvantages, the design of a novel cone calibration system is described. The paper delivers insight into the development, design and testing of this new calibration system. The measurement results show that the presented method gives accurate calibration results with a very low overall uncertainty. Due to its surprisingly simple structure, its low price and the low overall measurement uncertainty, it is the preferred method for calibrating UHF sensors for GIS applications.

Experimental Characterization of the Response of an Electrical and Communication Raceway to IEMI

This paper reports the results of two experimental campaigns aimed at studying the high-frequency response of a raceway containing low voltage power, telephone, and Ethernet cables, to external electromagnetic field illumination. The raceway was tested against HPEM transients inside a gigahertz transverse electromagnetic (GTEM) cell and low-power fields inside a reverberation chamber (RC). The high-power electromagnetic (HPEM) tests revealed that the low-voltage power cables have the greatest coupling under a hyperband illumination, compared to telephone and Ethernet cables. The RC tests allowed the determination of statistical transfer functions from random incident field configurations into DM voltage in cable loads. The responses were found to be governed by the raceway under test at the lower frequencies (below 1 GHz). Between 0.2 and 1 GHz, the raceway gives about 10 dB higher coupling than a short patch cable. The difference is even greater at lower frequencies and for shielded cables. In the frequency band 1-3 GHz, little difference was observed between short patch cables and the full raceway, but both were still significantly higher than direct coupling to the measurement card. Beyond 3 GHz, the coupling is clearly dominated by the terminal equipment. The experiments performed in this paper provide a better understanding of the expected induced voltages and currents in commercial cable systems when exposed to intentional electromagnetic interference (IEMI)-like signals.

Corrections to “Study of the Propagation of Common Mode IEMI Signals Through Concrete Walls”

Presents corrections to the paper, “Study of the propagation of common mode IEMI signals through concrete walls,” (Mora, N., et al), IEEE Trans. Electromagn. Compat., vol. 60, no. 2, pp. 385–393, Apr. 2018.

Study of the Propagation of Common Mode IEMI Signals Through Concrete Walls

In this paper, a model to analyze the propagation of intentional electromagnetic interferences disturbances along penetrating conductors into concrete walls is proposed. The model is based on the transmission line theory and considers the attenuation of the signal as a function of the water content of the concrete, the thickness of the wall, and the frequency of the signal. The model is validated with experiments performed with a vector network analyzer and a time-domain reflectometer. A numerical parametric study is performed in order to quantify the expected attenuation levels of a concrete wall with different water content levels. The simulation results show that the peak amplitudes of the disturbance can be significantly attenuated for both dry and wet concrete.

Reciprocity Theorem: Practical Application in EMC Measurements

This document reports part of the measurements developed under the project entitled “Evaluation of the reciprocity in EMC measurements.” The project aims to evaluate the technical feasibility of the implementation of the reciprocity principle in EMC-EMI measurements.