Shielding Effectiveness of the Gas-Insulated Bus Duct for Transient EM Fields Generated in a GIS During Switching Operations

Electromagnetic Disturbed Mechanism of Electronic Current Transformer Acquisition Card under High Frequency Electromagnetic Interference

“…So, it is necessary to study the coupling mechanism of EMI which impacts the output waveform of the ECT acquisition card. As former scholars have studied, when the operation of CB causes its working state to change, some EM energy oscillations will occur [30]. This phenomenon is a series of high-voltage, high-frequency narrow pulses generated from the switching action.…”

Mitigation of switching‐induced transient electromagnetic interference on control cable using Ni–Zn ferrite rings over cable sheath in gas‐insulated substations

“…The amount of the induced transient current in the sheath of the control cable results from integration of very small voltage sources, and is calculated from the axial electric field along the cable sheath and radial electric field along the terminals. The method of evaluation is indicated in the following equation [9,10]: where \documentclass{article}\usepackage{amsmath}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{amsfonts}\pagestyle{empty}\begin{document}$M =(\mathrm{Z}_{0} Z_{1} +Z_{0} Z_{2} )\times{\mathrm{\cos}}\beta L+j(Z_{0}^{2} +Z_{1} Z_{2} )\times{\mathrm{\sin}}\beta L$ \end{document}, λ is the wavelength of the cable sheath, β = 2 π/λ , L is the cable length, Z t is the transfer impedance of the control cable, E z and E r are axial and radial electric field, and x and z are the axial distances from the terminal of the cable.…”

“…For studying the effectiveness of the cable shield on the induced voltage, two types of material, such as copper and aluminum, with different relative permeability and conductivity are considered. The induced voltage on the central conductor of the cable can be indicated by [9–11]. where Z t and I are the sheath transfer impedance and the sheath current, respectively.…”