Andrei Ceclan

Layer recurrent neural network solution for an electromagnetic interference problem

The paper presents an original contribution related to the implementation of a neural network artificial intelligence (AI) technique through Matlab environment, on the study of induced AC voltage in the underground metallic pipeline, due to nearby high voltage grids. The advantage yields in a simplified computation model compared to FEM, and implicitly a lower computational time. In comparison with other neural network solutions identified in the literature, where the induced AC potential is directly evaluated, the authors of this paper propose a new neural network solution to evaluate MVP on the studied domain, using a larger training database for a large panel of different geometries.

Evaluation of induced AC voltages in underground metallic pipeline

Purpose – The purpose of this paper is to make a study of electromagnetic interference between electrical power lines and nearby underground metallic pipelines.Design/methodology/approach – The equivalent electrical circuit of the studied electromagnetic interference problem between electrical power lines and nearby metallic pipelines is created and solved using a loop currents technique based on a hybrid method. The used circuit solving technique was implemented in a software application developed by the authors.Findings – The authors have identified the influence of phase sequence on induced voltage level in an underground pipeline for a double circuit electrical power line. Also the effect of different normal operation and phase to earth fault currents have been revealed.Practical implications – The study has been made through a research project with the Romanian gas transportation company, in order to find the proper protection techniques for underground metallic pipelines.Originality/value – The pape...

Inductive and conductive interference problems for practical cases solved with special interpolation algorithms

In the paper are presented and discussed practical cases of subdivision of the right of way AC Power Lines / electric traction line / gas pipeline in sections (a circuit model) and also are briefly presented analytical solutions of the induced voltages and current densities in victim structures. Is created a special interpolation algorithm based on global interpolation functions for precise evaluation of the induced voltages values in different points on the underground pipeline, taking into account the measured data. Also, are applied numerical interpolation methods and/or nonlinear curve fitting procedures for determining a continuous function between the magnetic permeability and electrical induced currents, because in practice, there are only a set of available reactance measurements.

Numerical methods for induced voltage evaluation in electromagnetic interference problems

A numerical procedure employing the finite-difference method (FDM) is used in order to calculate the induced voltages across points on a underground pipeline, running parallel to a faulted line, and remote earth. A comparison is made between the results obtained with FDM and FEM. We develop a mathematical differential model and based on contour integral method was obtained the numerical form of the Helmholtz equation. We determine directly the numerical form of equation for non-homogeneous media, to clearly put in evidence the electromagnetic phenomena. A physical model for experimental calculus of induced voltage in an underground pipeline will be created based on the differential numerical model.

Simulation of interferences between power lines and gas pipelines in unbalanced phase currents state

Purpose – The purpose of this paper is to compute the values of induced voltages and currents in an underground gas pipeline, which shares the same right of way with a high voltage power line (HVPL) in unbalanced phase currents regime, in order to detect the possibility of the AC corrosion occurring in the pipeline.Design/methodology/approach – The analysis of the induced voltages in metallic structures (gas pipeline) was done using a professional analysis and modeling software which uses the electromagnetic field method.Findings – It was shown that during fault conditions, large currents and voltages are induced on the pipelines, which may pose a threat to operating personnel and equipment. Induced voltages also occur in cases of unbalanced phase currents of the HVPL, which may pose a threat voltage that could lead to damages of the underground gas pipeline due to corrosion phenomena.Practical implications – Because the electromagnetic field approach involves complicated analytical expression and introdu...

Lightning-Inverse Reconstruction by Remote Sensing and Numerical-Field Synthesis

An inverse remote-sensing procedure is presented for reconstructing the spatial waveform of the lightning return stroke current throughout a numerical-field synthesis procedure, based on working regularization methods. The approach uses as input data the acquisition of time-domain recordings of the electric and/or magnetic field generated by the lightning current, at various locations on the ground and converts these signals into harmonics by Fourier decomposition. This combination between the proposed solving procedures and harmonic filtering yields numerical results that are in good agreement with the testing functions.

On a return stroke lightning identification procedure by inverse formulation and regularization

This paper proposes an original inverse procedure and numerical regularization for the return stroke current identification.

Analysis of inrush and fault currents measurement errors generated by the current transformer saturation

During saturation, a clipping effect is observed on the secondary side, leading to a false reading of the RMS value of the primary current. The present paper shows some experimental date about the effect of current transformer saturation and validates a method for reevaluating sampled data related to inrush currents.

Recent advances on the influence of power transformers inrush current over the optimization of medium voltage feeder protection

The present paper shows the usefulness of evaluating inrush currents in Medium Voltage grids in order to improve the operation of overcurrent protection systems and allow for real-time computation of new settings in Smart Grids.

On some return stroke lightning identification procedures by inverse formulation and regularization

This paper proposes an original electromagnetic inverse procedure and numerical regularization for the return stroke current identification, from electric and magnetic field measurements in the area of the impact. The resulted evaluations prove to be in a very good agreement with the actual data, moreover the precision is considerably improved.