ASSESSMENT OF ELECTRICAL INTERFERENCE ON METALLIC PIPELINE FROM HV OVERHEAD POWER LINE IN COMPLEX SITUATION

Sharing corridors between high voltage alternating current (HVAC) power lines and metallic pipelines has become quite common. Voltages can be induced on pipelines from HV power lines, which may cause a risk of electric shock to the operator and serious corrosion damage on metallic pipelines. This paper aims to examine the capacitive coupling between aerial metallic pipelines and HV power lines in perfect parallelism case and in general situation which is formed by parallelism, approaches and crossings, using a combination of charge simulation method and Artificial Bee Colony (ABC) algorithm. The electric field at the pipeline's surface and the induced voltage on the pipeline are strongly affected by the pipeline separation distance. The presented simulation results are compared with those obtained from the admittance matrix analysis, a good agreement has been obtained

AC CORROSION PHENOMENON AND MITIGATION IN BURIED PIPELINE DUE TO VERY-HIGH-VOLTAGE (VHV) OVERHEAD TRANSMISSION LINE EFFECT

The presence of a very-high-voltage (VHV) electricity transmission line nearby a metallic pipeline can be a source of dangerous effects for this pipeline due to the electromagnetic field generated by this power line, it can induce a considerable voltage which may threaten the safety of operating personnel and the integrity of the pipeline. The main purpose of this paper is to evaluate the electromagnetic coupling effect in a buried metallic pipeline located in close proximity to a very-high-voltage (VHV) overhead transmission line using the Faraday's law and nodal network analysis under steady state conditions, as well as to estimate the possibility of AC induced corrosion of the metallic pipeline. The obtained results show that the induced voltage on the metallic pipeline exceeds the maximum threshold value recommended by the international regulations CENELEC and NACE, the AC corrosion current density surpasses the allowable value indicated by the specialized majority of corrosion studies. Therefore, a mitigation technique based on a pipeline grounding system is proposed to reduce the voltage induced on the pipeline to safe limits, in order to remedy the hazardous potential effects. The adopted mitigation technique has achieved better efficiency by reducing the induced voltage well below the safety limit

ACCURATE COMPUTATION OF MAGNETIC INDUCTION GENERATED BY HV OVERHEAD POWER LINES

This paper proposes a 3D quasi-static numerical model for the magnetic induction calculation produced by the high voltage overhead power lines by using the Current Simulation Technique (CST) combined with the Particle Swarm Optimization Algorithm (PSO), in order to determine the appropriate position and number of the filamentary current loops for an accurate computation. The exact form of the catenary of the power line conductors is taken into account in this calculation. From the simulation results, the effect of the conductor sag is largely noticed on the magnetic induction distribution, especially at the mid-span length of the power line where the magnetic induction becomes very significant, the maximum magnetic induction strength at 1 m above the ground level recorded at mid-span point is 8.87 μT, at the pylon foot, the maximum value is significantly reduced to 3.94 μT. According to these values, we note that the limits set by the ICNIRP guidelines for magnetic induction strength are respected for occupational and public exposure. The simulation results of magnetic induction are compared with those obtained from the 3-D Integration method, a fairly good agreement is found

ELECTRIC FIELD MODELING AND ANALYSIS OF EHV POWER LINE USING IMPROVED CALCULATION METHOD

This paper aims is devoted to modeling and simulation of electric field created by EHV power transmission line of 275 kV using an efficient hybrid methodology, the charge simulation method (CSM) with the Simplex Simulated Annealing (SIMPSA) algorithm in order to find the optimal position and number of fictitious charges used in CSM for an accurate calculation. Various factors that affect the electric field intensity were analyzed; it is found that the influence of the conductor sagging is clearly remarked, the maximum electric field strength at 1 m above the ground level recorded at mid-span point of the power line is 3.09 kV/m, in the proximity of the pylon, the maximum value is significantly reduced to 1.28 kV/m. The configuration type of the transmission line (single or double circuit) and the arrangements of phase conductors on double circuit pylons have a significant effect on the levels of electric field around the transmission line. For a single circuit, the triangular configuration provides the lowest maximum value of electric field. For a double circuit, the inverse phase arrangement (abc-cba) or low-reactance phasing produces the lowest maximum value of electric field. The resulting maximum electric field levels were found below the exposure values set by the ICNIRP and IRPA standards for both occupational and general public. The simulation results of electric field are compared with those obtained from the COMSOL 4.3b Multiphysics software, a fairly good agreement is found

Fault diagnosis of induction motors rotor using current signature with different signal processing techniques

The popularity of asynchronous machines, particularly squirrel cage machines, stems from their inexpensive production costs, resilience, and low maintenance requirements. Unfortunately, potential flaws in these devices might have a negative impact on the facility's profitability and service quality. As a result, diagnostic tools for detecting flaws in these types of devices must be developed. Asynchronous machine problems can be diagnosed using a variety of methods. Signal processing techniques based on extracting information from characteristic quantities of electrical machine operation can provide highly useful information about flaws. The purpose of this research is to develop efficient algorithms based on numerous signal processing approaches for correctly detecting asynchronous cage machine rotor defects (rotor bar ruptures)

Optimization of induced voltage on buried pipeline from HV power lines using grasshopper algorithm (GOA)

The buried metallic pipeline which parallels to the HV power line is subject to induced voltages from the AC currents flowing in the conductors, these voltages can affect the operating personnel, pipeline associated equipment, and the pipeline integrity. This paper analyses the induced voltage and current on the buried pipeline running parallel to HV power lines. It also presents an optimization procedure of different parameters that affect the level of the induced voltage in the pipeline during normal operating conditions. A comparison study between the proposed optimization algorithms (GOA, GE, DE and PSO) is done with a maximization of a given objective function. The simulation results establish that the GOA algorithm provides a faster convergence and better solution than the other optimization algorithms. Thus, the statistical analysis according to Friedman’s rank test confirmed the superiority of this proposed algorithm. Furthermore, the results show that the parameters optimization of the metallic pipeline is an effective approach to provide the best performance for mitigation which is generally sufficient to reduce the induced voltage experienced by the buried metallic pipeline to enforce the safety limit

IMPROVED LS-SVM USING ACO TO ESTIMATE FLASHOVER VOLTAGE OF POLLUTED INSULATORS

The reliability of insulators under polluted environment is one of the guiding factors in the insulation coordination of high voltage transmission lines. In order to improve understanding of the flashover phenomenon in polluted insulators, several experimental studies and mathematical approaches have been made‎ in‎ last‎ year’s.‎ In‎ this‎ paper,‎ the‎ critical flashover voltage behavior of polluted insulators has been calculated and a hybrid model between machine Learning (ML) and optimization technique has been proposed. For this purpose, firstly the ant colony optimization (ACO) technique is utilized to optimize the hyper-parameters needed in least squares support vector machines (LS-SVM). Then, a LS-SVM-ACO model is designed to establish a nonlinear model between the characteristics of the insulator and the critical flashover voltage. The data used to train the model and test its performance is derived from experimental measurements and a mathematical model. The results obtained from the proposed model are in good accord with other mathematical and experimental results of previous researchers

Fault diagnosis of induction motors rotor using current signature with different signal processing techniques

The popularity of asynchronous machines, particularly squirrel cage machines, stems from their inexpensive production costs, resilience, and low maintenance requirements. Unfortunately, potential flaws in these devices might have a negative impact on the facility's profitability and service quality. As a result, diagnostic tools for detecting flaws in these types of devices must be developed. Asynchronous machine problems can be diagnosed using a variety of methods. Signal processing techniques based on extracting information from characteristic quantities of electrical machine operation can provide highly useful information about flaws. The purpose of this research is to develop efficient algorithms based on numerous signal processing approaches for correctly detecting asynchronous cage machine rotor defects (rotor bar ruptures

Detection of partial rotor bar rupture of a cage induction motor using least square support vector machine approach

Squirrel cage induction motors suffer from numerous faults, for example cracks in the rotor bars. This paper aims to present a novel algorithm based on Least Squares Support Vector Machine (LS-SVM) for detection partial rupture rotor bar of the squirrel cage asynchronous machine. The stator current spectral analysis based on FFT method is applied in order to extract the fault frequencies related to rotor bar partial rupture. Afterward the LS-SVM approach is established as monitoring system to detect the degree of rupture rotor bar. The training and testing data sets used are derived from the spectral analysis of one stator phase current, containing information about characteristic harmonics related to the partial rupture rotor bar. Satisfactory and more accurate results are obtained by applying LS-SVM to fault diagnosis of rotor bar

Influence of comorbidities and medication use on tilt table test outcome in elderly patients

This paper proposes a methodology based on Faraday's electromagnetic induction law (EMF) for evaluating the induced voltage produced by high voltage power line on an aerial metallic pipeline located parallel in its immediate vicinity under normal operating condition. It also describes the procedure of the induced voltage mitigation using the passive loop technique combined with the particle swarm optimization algorithm (PSO). The presence of a pipeline in the vicinity of an overhead power line strongly disturbs the mapping of the magnetic induction produced by this power line. The mitigation efficiency is significantly improved by optimizing the position of the loop conductors, by increasing the number of loops and the use of a shielding magnetic material of high relative permeability. The obtained simulation result is compared with that obtained by the Carson's formulas. A good agreement was obtained