High-voltage Electric Transmission Research Articles

Revolutionizing heat distribution: A method for harnessing industrial waste heat with supra-regional district heating networks

In both practice and literature, there is a lack of a concept for a supra-regional district heating network that efficiently transports heat from renewable and industrial waste heat sources to multiple heat sinks and regional district heating networks, like the high-voltage electricity transmission network in the electricity sector. This paper addresses this gap by presenting a novel method for the basic design of a supra-regional district heating network and its evaluation, along with key performance indicators for assessment. The method highlights essential data requirements and the derivation process necessary to enable the integration of such a heating network. Additionally, it describes how a basic design of such a network can be made feasible and evaluated. This method is then applied to a case study to demonstrate its implementation for a real-world application. Furthermore, this case study aims to either demonstrate or provisionally disprove the general feasibility of a supra-regional district heating network. The results indicate that the implementation of such a network has a positive impact on the CO2 balance and primary energy demand. The case study further demonstrates the technical feasibility of such a network, showing that a high linear heat density can be achieved through integration and that temperature levels within the network can be maintained adequately. This study confirmed that the developed method can effectively assess whether further investigations into implementing a supra-regional district heating network in a specific region are warranted. Additionally, the method offers a guideline on how to initially design such a network.

Electric Field Improvement for High-Voltage Bushings

Resin-impregnated paper (RIP) bushing has gained significant interest due to its extended application in Extra High Voltage (EHV) and Ultra High Voltage (UHV) electricity transmission systems. However, the design criterion of its overall structure, the geometry parameters of the condenser layers, and stress release devices, etc., are still not fully understood. This article proposes a unique electric field optimization technique to integrate both the analytical and the numerical methods. The charge simulation method (CSM) is employed to create the overall equipotential surface, within which the finite element analysis (FEA) is adapted to study the localized field enhancement effects, taking into consideration the multi-physics coupled fields. A case study is performed on an actual UHV bushing. The results are compared to the traditional methods, to demonstrate the benefit of the hybrid method.

Computational study of the Transmission pole during downburst using ANSYS, considering fluid-structure interactions

A downburst is described as a strong downdraft that causes a devastating wind outburst on or near the earth surface. Such occurrences are more common during thunderstorms. Downbursts generally impinge on the ground and convect radially in all directions from the point of contact. Downbursts have been widely documented as a regular cause of high voltage electrical transmission tower and pole failures in numerous nations. The flow dynamics of impinging jets are investigated using numerical models, with applicability to downburst-related high intensity winds. The downburst is simulated using three primary viscous models (, , and RANS). These three viscous models are used to simulate downburst in two dimensions. The RANS viscous model is used for further investigation. To determine the temporal variant characteristics of a downburst, both steady and transient state simulations are performed. The flow is quasi-periodic, with vortex rings formed by the initial jet instability impinging on the surface, where they find an unstable separation reattachment of the boundary layer. Fluid-structure interactions (FSI) are multiphysics problems that cannot be handled using single physics equations. To determine the impacts of downburst on transmission poles, a 2-D steel pole 8 metres high with a fixed base is put near the downburst. Downburst pressure is measured on a transmission pole. The stresses and deflections caused by the pressure distribution on the tower due to varying fluid domain dimensions and jet velocities on the transmission poles are determined using one way coupling, from 2-D transmission pole geometry to 3-D transmission pole geometry.

Insights into the Thermal Performance of Underground High Voltage Electricity Transmission Lines through Thermo-Hydraulic Modelling

In this paper, a flexible numerical framework to provide thermal performance assessment for the underground buried cables, considering different geological and meteorological conditions, has been presented. Underground cables tend to retain the heat produced in the conductor, so complex coupled thermo-hydraulic response of the porous medium surrounding the cables needs to be assessed to prevent cable overheating and the associated reduction in cable capacity for carrying current. Applying a coupled thermo-hydraulic model within the developed numerical framework to conduct a health assessment on a subset of National Grid Electricity Transmission’s underground cables, this study provides novel insights into the thermal behaviour of buried circuits. The results indicate that backfill and surrounding native soil have the dominant effect on the thermal behaviour of cables, while the amount of precipitation and ambient temperature were found to have less impact on cable’s thermal behaviour. The findings strongly infer that the nature of the overloading which is undertaken in practice would have no ongoing negative impact, suggesting that more frequent or longer duration overloading regimes could be tolerated. Overall, this study demonstrates how the developed numerical framework could be harnessed to allow safe rating adjustments of buried transmission circuits.

A copula‐based approach on optimal allocation of hot standbys in series systems

AbstractIn this paper, we propose a copula‐based approach to study the allocation problem of hot standbys in series systems composed of two heterogeneous and dependent components. By assuming that the lifetimes of components and spares are dependent and linked via a general survival copula, optimal allocation strategies are presented for the case of one and two redundancies at the component level. Further, redundancies allocation mechanisms are also compared between the allocations at the component level and the system level. For the case of one hot standby, we find that the performance of the redundant system at the component level is always worse than that at the system level. For the case of two hot standbys, the reversed allocation principle (i.e., Barlow–Proschan principle) is valid. Numerical examples and applications are also provided as illustrations. A real application on improving tensile strength of cables in high voltage electricity transmission network systems is presented for showing the applicability of our results.

High-Voltage and High-Power Electricity Generation, Transmission and Management of MR-SPS

High-Voltage and High-Power Electricity Generation, Transmission and Management of MR-SPS

Calculation of the Voltage Unbalance Factor for High-Speed Railway Substations with V-Connection Scheme

In France, high-speed railway lines are powered by a 2 × 25 kV/50 Hz electrification system. The substations include two single-phase transformers connected to the high-voltage electrical transmission network on different pairs of phases according to a so-called “V-connection scheme”. In practice, due to the large variations in the power absorbed by the trains, this connection does not make it possible to satisfactorily limit the unbalance in the three-phase voltages. In order to correctly size a balancing system to be associated with the substation, it is necessary to calculate, with precision, the voltage unbalance factor as a function of the power drawn by the trains. In its first part, this paper presents modelling of the substation and proposes an algorithm which allows for the calculation of the upstream line voltage as a function of the power consumption at the secondary of the transformers. The voltage unbalance factor can then be determined over a long period of operation. In the second part of this paper, the same approach is applied with an unbalance-compensator based on Steinmetz circuits controlled by AC choppers. Finally, in both cases, the results of the calculations are validated by simulations performed with PLECS simulation software.

OBSERVATIONAL STUDY OF ELECTRICAL BURN CASES AT A TERTIARY CARE CENTRE IN CENTRAL INDIA

ABSTRACT Background :- Electricity has become an integral part of our lives in today’s era of technology . Electrical burn injuries comprise a low fraction of the entire burn admissions but they are potentially a mutilating type. The aim of this study is to know the demographic pattern of electric burn cases in our region, along with the morbidity and management of electric burn injuries in a tertiary centre of central india. Methods :- This was a retrospective study conducted by reviewing the medical records of all burn admissions from July 2017 to June 2019 and data was analysed for demographic characteristics and outcomes and patterns of electric burn injury Results :- Out of 26 total electric burn cases, maximum cases (65.38%) were adult above 20 years of age. Having male to female ratio of 3.5:1 , most of them belonged to rural place. (84.61%) Of all the cases studied,maximum were of High Voltage (>1000 V) Injury 61.53%, encountered mostly in outdoors and at work places.Hand (50%) was the commonest part to be affected. 61.53% of all affected individuals had to undergo a surgical intervention of which 50% underwent debridement, with a mean hospital stay of 27.08+/-12.09 days for high voltage injuries Conclusions:- Electrical injuries are generally preventable. This epidemiological study on the patients of electric burn suggests that most of the human and economic losses caused by the accidents leading to electric burn injuries were young males, hailing from rural areas and suffered high voltage burns, which could have been prevented by implementation of safety measures at work place. Hence general education regarding safety measures while using the electricity should be given in primary schools itself. High voltage electrical transmission cables should be placed underground.

Improving US Energy Security: Granting FERC Siting Authority over Interstate High Voltage Electric Transmission

The Biden Administration and the US Congress are giving serious consideration to granting the Federal Energy Regulatory Commission (FERC) the authority to site high voltage (HV) interstate electric transmission lines. FERC already has authority under the Natural Gas Act (NGA) to regulate the siting of and rates charged by interstate natural gas pipelines and storage facilities. Proponents of giving FERC such additional authority point to the extensive buildout of the natural gas pipeline system. These proponents believe that FERC could do the same with interstate HV electric transmission.

Determination of isolator damages in electric power transmission lines with continuous wavelet transform and multitape power spectrum density

PurposeDetection of deformation of devices in high voltage electricity transmission line systems is an important issue in terms of economy and reuse. This study is aimed to detect devices that are deformed or thought to have suffered due to environmental and electrical reasons.Design/methodology/approachIn this experimental study, it was ensured that the sound and deformed insulators used in energy transmission lines were determined by the analysis of the sounds obtained by using the impact method. Equal intensity impact was applied to the isolator using the pendulum and the resulting sound noise signal analyses were made using power spectral density (PSD), magnitude scalogram (MS), multitape power spectrum density (MPSD) and continuous wavelet transform (CWT) methods in the study. In the analysis results, the isolators that are not visible to the eye and have certain damage were successfully separated from the intact insulators. Especially, MPSD and CWT analysis results are quite satisfactory.FindingsDamage analysis of insulators used in electricity transmission lines has been made. A total of 40 insulators were examined in two categories in their group, both damaged and not damaged. Data collection system was established. The data obtained from the data collection system were analysed and compared using four analysis methods. PSD, MS, MPSD and CWT analyses were made in the study. All the analyses carried out generally contain features that distinguish damaged and undamaged insulators from each other, the most successful results are MS and CWT results. CWT results are very successful in terms of time and amplitude, and it has been proposed as a method that can be used to separate damaged and undamaged insulators.Originality/valueIt can be suggested as a result of experimental tests that the results of CWT analysis can be used in the pulse noise method in isolators to be tested for reuse in electrical power transmission lines.

Effect of high-voltage power lines electromagnetic field on growth and development of green bean (Phaseolus vulgaris L.)

Relevance. High voltage electric power transmission lines (HVEPTL) cover a fairly large area of agricultural land all over the world. Investigations of electromagnetic field effect on growth and development of plants are held in various countries. The reaction of individual plant species and even varieties to the electromagnetic field manifests itself in different ways. The network of HVEPTL is growing steadily in our region as well. Nevertheless, information about the effect of the electromagnetic field on bean plants is rather scares. The aim of the present work was to evaluate HVEPTL effect on the growth and development of vegetable beans, depending on the intensity of the electromagnetic field.Material and Methods. The work was achieved on green beans Phaseolus vulgaris L. (Sakfit, Pagoda, MBZ 556, Arishka cvs) grown in conditions of different electromagnetic field values under HVEPTL. Biometrical parameters, plant productivity, yield, dry matter, photosynthetic pigments content, ascorbic acid, total antioxidant activity and total phenolics were determined.Results. In the ranges of electric field values from (5-10) to (400-440) B/m and magnetic field from 0 to 0.53 μT a beneficial effect of electromagnetic field on accumulation of leaves photosynthetic pigments (15-65% increase of chlorophyll а and 6-52% increase of chlorophyll b), polyphenol content (increase up to 17%), antioxidant activity (1-15% increase), and dry matter content (2,5-11% increase) and beans ascorbic acid levels (12-28% increase) were registered. Accordingy, increased plants growth, development and productivity were demonstrated. Peculiarities of beans plants grown under HVEPTL included decrease leaves carotene levels at electric field level of 60-100 B/m (70 m form HVEPTL), and lack of correlation between chlorophyll and carotene in leaves and total antioxidant activity and phenolics content at the stage of technical ripening.

Influence of spatial arrangement of wires on electromagnetic ecology near high-voltage power transmission lines at railway station

Based on computer modeling, we have considered the effect of a spatial arrangement of wires on electromagnetic pollution of environment on high-voltage electric transmission lines. This pollution is determined based on voltages of electric and magnetic fields. We have considered two variants of the arrangement of wires on power towers. The first version provides for the location of wires in a vertical plane and the second variant provides for the location of the wire at corners of a triangle. Three modes of the high-voltage power line operation were considered: 1) normal with a load at the receiving end of the power line 120 + j90 MVA; 2) break of the phase A wire at the starting end of the power line; 3) two-phase short circuit. The simulation result in the Fazonord software package showed that the spatial arrangement of the wires significantly affects the maximum amplitudes of the electric and magnetic fields at a normalized height of 1.8 m. Moreover, the nature of dependence of the voltage on the x-axis coordinates directed perpendicular to the path of the analyzed power transmission section changes. The results of the simulation showed that under symmetrical load for a power line with a triangular arrangement of wires, the maximum value of the amplitude of the electric field show insignificant increase in comparison with high-voltage power lines with vertically arranged wires. The same indicator for the magnetic field shows increase of one and a half time.

Partial Discharge of Polyurethane/ Organoclay Composite Coated on Aluminum Conductor Overhead Lines

Aluminum conductor have been used worldwide as the primary conductive materials for high voltage electrical transmission lines. The partial discharge behavior of the aluminum conductor have been obeserved during operation due to the transmission line's performance to serve electricity. The partial discharge of aluminum alloy coated by polyurethane/organoclay (PClay) composite material was studied. PClay composites were prepared by adding organoclay with different content in polyurethane as a matrix then coated on an aluminum conductor sample. A partial discharge test was conducted to obtain the behavior of partial discharge versus voltage. It was found that an escalation of organoclay content in the polyurethane reduce partial discharge appears.

Performance-Related Assessment of the Potential Use of Sawing Sludge in Cementitious Fluidized Thermal Backfills

The management of sawing sludge originated from cutting operations of ornamental stones represents a challenging task as a consequence of its peculiar composition that includes non-negligible amounts of heavy metals resulting from the wear and tear of cutting tools. The aim of the research work presented in this paper was to investigate the feasibility of using these by-products as supplementary constituents of cementitious mixtures employed for the formation of Fluidized Thermal Backfills (FTB). These mixtures are designed and produced for filling operations in pavement subgrades in which high-voltage electrical transmission cables are buried for protection purposes. Two different types of sawing sludge were thoroughly analyzed from a physical and chemical point of view and thereafter employed for the laboratory production of four FTB mixtures. Then, these were subjected to thermal, mechanical, and environmental tests in order to verify their suitability for their intended use. All investigated FTB mixtures exhibited a satisfactory and stable thermal conductivity, and they also displayed enhanced stiffness properties in comparison to standard subgrade and sub-base materials. Controversial results were obtained with respect to environmental properties resulting from leaching tests, thus suggesting that further investigations are needed before any full-scale application can take place.

Integrating multicriteria decision-making analysis for a GIS-based settlement area in the district of Atakum, Samsun, Turkey

The last century witnessed a boom in the world population, reaching an unprecedented level. In particular, in recent decades, the population has concentrated in cities. Migration from rural areas to urban areas brings many problems to urban areas, necessitating the opening of new settlement areas. These new settlement areas that are needed are mostly determined in line with the initiatives of local authorities based on the situation of infrastructure facilities, not scientific evaluations. If the wrong places are selected, various natural events each year may cause the loss of property and lives, in addition to significant amounts of energy consumption. This study uses various parameters and creates a method for place selection based on multiple criteria. The district of Atakum in the city of Samsun, which has been subject to continuous migration and where new settlement areas have been established, is selected as the study area. Within the scope of this study, in addition to landslide and flood risks, which constitute the most important natural disasters in the region, situations of high voltage electricity transmission lines in places where the establishment of a residential area would be objectionable are evaluated. The situation of biocomfort, which is significantly important, especially with respect to energy efficiency as well as human health, peace, and comfort, is also evaluated. This study is conducted based on these criteria, and as a result, it calculates that only 15.11% of the district of Atakum is appropriate for use as a settlement area. In addition to serving as a reference for the short- and long-term area planning studies that will be conducted in the region, this study also holds significance due to the new perspective it offers regarding urban planning studies.

Analyzing the Limit Loading of Transmission Tower by Means of Finite Element Model

The truss structure has been widely used in the area of high-voltage electric power transmission due to its limited mass and great stiffness. The carrying capacity should be known in advance before the practical usage of transmission tower. As a result, analyzing the limit loading of transmission tower can be significantly useful. In this research, a model of transmission tower structure has been established by a software named Abaqus 6.14. By imposing different loading forces to the finite element model, the locations of limit stress and displacement were figured out. It has shown that the truss structure in this article can bear no more than 198 kN of loading. Stresses meanly distribute in the two side of the tower body, decreasing with the increasing height. The limit stress shows up at the bottom and is at same side of loading force. Stress and displacement responses fit Hooke’s law perfectly, in other words, the proposed finite element model can be used in the design of transmission tower in practice.

Dielectric characterization of vegetable oils during a heating cycle.

The knowledge of the dielectric properties of oils is of great importance for several industrial applications, such as microwave-assisted oil frying for foods and high voltage electric power transmission. In this paper, we present the complex permittivity of vegetable oils (canola, olive, soybean, coconut) at 2.50GHz using the cavity perturbation technique from 28 to 200°C (temperature close to the smoking point of oils). The measurements were taken with a cylindrical cavity operating at the TE111 mode with an unloaded Q of 4950. In addition, free fatty acids, peroxide index and color were measured before and after heating.

Application of direct MRAC in PI controller for DC-DC boost converter

<p>Almost all electronic components require a DC power supply at present days. The needs of DC power supplies from low voltage scales, medium voltages such as generators, to high voltage scales for high voltage electricity transmission. The improvement of PI controller performances is presented in this paper. The adaptation gains improve transient response of DC-DC Boost Converter several operating conditions. Massachusetts Institute of Technology (MIT) rule is applied as an adaptive mechanism to determine the optimal control parameters in some conditions. The used adaptive control technique is Direct Model Reference Adaptive Control (MRAC), this method as able to control system in some various input voltage. The proposed method has a stable response and able to reach the model reference smoothly. However, the response of the system has instantaneously overshoot and follows the response back of model reference. The responses of proposed controller have short period of rise time, settling time, and overshoot.</p>

Why the vision of interregional electric transmission development in FERC Order 1000 is not happening

The Federal Energy Regulatory Commission (FERC) on March 19, 2020 announced a Notice of Proposed Rulemaking (NOPR)iiFERC Docket RM20-10-000. to further investigate how financial incentives might be used to encourage development of high-voltage electric transmission in the United States. An extension of previous efforts in FERC Order 679 issued in 2006, the NOPR-proposed incentives would consist of up to 250 additional basis points of equity return to be allowed on qualifying transmission projects. The NOPR was published in the Federal Register on April 2, and public comments were due back to FERC by July 1.Such incentives, if adopted, would be helpful to address prior FERC business that is yet undone. Issued in 2011, FERC Order 1000, “Transmission and Cost Allocation by Transmission Owning and Operating Utilities” among other things envisioned coordinated planning of interregional transmission developments spanning between individual Regional Transmission Organizations (RTO) and Independent System Operators (ISO), the operators of the FERC-regulated organized wholesale markets. In addition to traditional goals of generator interconnection and service reliability, the purpose of such interregional transmission development was to support public policy goals including renewable energy development, and lower costs for consumers.But little or no such interregional development has happened since Order 1000. Why? The authors have spent the last several years promoting development of one such interregional transmission project. While the effort is ongoing, the on-the-ground experience to-date clearly shows the reasons why interregional development envisioned by FERC Order 1000 is not happening. The authors offer solutions to the issues, including how the new FERC NOPR for transmission incentives can be helpful.

Modeling and Diagnosis of Joints in High Voltage Electrical Transmission Lines

In this paper a new method is developed and described, aimed at the modeling and diagnosis of the joints connecting the ends of two cables on a high voltage electricity pylon. Identifying the anomalous joint behaviour through the line frequency response analysis is the first objective of the work. For this reason, it is necessary to model the whole overhead line with a lumped circuit and studying the joint electrical parameter variation. The problem is approached in multiple steps: modelling, testability analysis of the model, optimal frequency selection, identification of the possible failures. Some simulated cases are included in order to show the potentialities of the method.