Power Cable Lines Research Articles

Optimization of monitoring systems power cable lines

RELEVANCE. The length and complexity of the geography of medium voltage cable lines is at a high level. Such lines extend underground, on supports in the air. In order to constantly maintain the reliability of city power supply at a high level, any interruptions and accidents should be promptly corrected.TARGET. The main goal of the work is to develop the theory of medium voltage CL research, to practically and theoretically substantiate the search for the most convenient and effective installation for CL diagnostics, to study and develop possible modifications of CL diagnostic installations.METHODS. A variant of CL diagnostics based on the CPDA-60 installation is proposed, which makes it possible to find and localize the places where defects occur in the insulation based on the measurement and analysis of partial discharges (PD). Suitable for insulation monitoring in all types of high voltage cables. The CPDA installation can be used when testing new cable lines being put into operation, and to analyze the condition of old cables in operation.RESULTS. Cable lines require an integrated approach to diagnostics and monitoring, since the reliability of modern authentication systems for the generation and distribution of electricity is largely determined by the electrical reliability of electrical equipment. Technical diagnostics of equipment is a key link, the quality of which determines the efficiency of the processes of organizing production activities, strategic planning and renovation of electric grid assets.CONCLUSION. The study and analysis of the presented data and research allows us to form a conclusion regarding the method of measuring and localizing partial discharges (PD) in power cable lines (CL) using the Online Wire Testing System (OWTS) diagnostic system. The OWTS system allows real-time measurements without interrupting cable lines, making it especially valuable to the energy industry. Thanks to the introduction of advanced technologies and signal processing algorithms, the method has high accuracy and sensitivity to minimal manifestations of private discharges, which allows not only to detect, but also to accurately localize the location of defects in the insulation. The use of this method can significantly increase the service life of power cables, reduce the likelihood of sudden accidents and, as a result, reduce the cost of repair and maintenance of electrical power equipment. Ultimately, improvements in diagnostic and monitoring techniques, including the method of measuring and localizing PD in power lines using OWTS, represent a significant step towards improving the reliability and safety of electrical power systems. This will not only reduce operating costs, but also ensure uninterrupted and high-quality power supply to consumers.

Investigation of Impedance Determination using Two-Point High Frequency Injection Technique for Non-Contact Voltage Measurement System

Energy management facilities are becoming more necessary due to the growth of smart energy and microgrid technologies. Convenient access to information on energy consumption is an advantage for energy planning and management and secure for the operators. Consequently, these conceive the idea of developing non-contact sensor approach to replace the conventional energy measurement while maintain full accessibility to voltage and current information. This paper proposes a method of non-contact conductive voltage measurement with an automated calibration system. The previous application of non-contact voltage measurement systems in the low-voltage range used a method based on the capacitive coupling principle by covering a metal plate around an insulated power line cable. The important factor of measurement accuracy depends on the determination of impedance occurring between the conductors within the cable and the metal plates attached to the cable surface by insulating as a dielectric. The proposed impedance determination process employs a two-point high-frequency signal injection technique that transmits a reference signal to calculate the established parasitic impedance value. From the high-frequency injection technique, the resulting impedance can be calibrated throughout the reverse calculation to measure the actual voltage of the power line. The experimental results of the proposed voltage measurement system can measure the actual voltage of the power line with the capability to calibrate the impedance due to the variation in the environment and eliminate noise errors from the instability under various conditions.

Hybrid Wi-Fi and PLC network for efficient e-health communication in hospitals: a prototype

E-health is being adapted in modern hospitals as a significant addition to the existing healthcare services. To this end, modern hospitals urgently require a mobile, high-capacity, secure, and cost-effective communication infrastructure. In this paper, we explore potential applications of a hybrid broadband power line communication (PLC) and Wi-Fi in an indoor hospital scenario. It utilizes the existing power line cables and Wi-Fi plug-and-play devices for indoor broadband communication. Broadband power line (BPL) adaptors with Wi-Fi outputs are used to build an access network in hospitals, particularly in areas where the wireless router signal is poor. The Tenda PH10 AV1,000 AC Wi-Fi power line adapter is a set of BPL adapters that offer operational bandwidth of up to 1,000 Mbps. These adapters are based on the HomePlug AV2 protocol and can provide a data rate up to 200 Mbps on the physical layer. An experiment using the PLC Wi-Fi kit is carried out to show that a Wi-Fi and PLC hybrid network is the best candidate to provide wide range of practical applications in a hospital including, but not limited to, telemedicine, electronic medical records, early-stage disease diagnosis, health management, real-time monitoring, and remote surgeries.

Development of correction coefficients for cable cross-sections selection in polymeric cable channel

Relevance. The need to develop correction coefficients for selecting cable sections when laying in the polymeric cable channel in the Russian Federation. Currently, there are no recommendations fixed by the state standards for laying cable power lines in polymer pipes. Aim. To develop correction factors for laying cable power lines in the polymer cable channel. Objects. Cable transmission lines laid underground in polymer pipes. Methods. Numerical simulation of combined frequency-stationary method; determination of correction factors based on interpolation of model results; evaluation and analysis of comparison of cables in corrugated and smooth polymer pipes. Results. Calculations of the long-term current load for cables laid in the polymeric cable channel showed the effectiveness of this method of laying cable lines. The use of pipes with smooth walls makes it much more efficient to remove heat from cables into the environment (compared to a corrugated pipe), which allows you to increase the capacity of the same cable by about 25%, depending on the number of pipes laid nearby. Based on the results of the simulation of the thermal mode of corrugated and smooth polymer pipes, it can be concluded that corrugated pipe significantly complicates heat removal from the cable system to the environment (soil). This is due to the presence of air gaps in the ribbed structure of the corrugated pipe. The gaps filled with air act as a heat-insulating layer, unlike a smooth pipe in which this gap is absent. The developed coefficients will take into account the influence of the location of cables on their allowable current already at the design stage, which will reduce the cost of power transmission losses due to the wrong cable cross-section and high temperature.

Advanced topographic-geodetic surveys and GNSS methodologies in urban planning

Abstract The relevance of the problem examined is the need for research to ensure the safety and efficiency of construction and operation of utility networks, in light of the rapid development and growth of urban infrastructure. The purpose of this research is to explore and evaluate the application of topographic-geodetic studies in the context of the design and construction of utilities. The methods used include analytical method, classification method, functional method, statistical method, synthesis method. At the preparatory stage of works the schedule of all stages of project implementation was developed, coordinate and height systems accepted in the territory of the settlement, topographic and geodetic materials, general plans, detailed planning plans, and schemes of settlement development were established. Executive surveys, the territory of Aksukent settlement, and other materials and documents identified in the process of preparatory works were collected and analysed. Using an unmanned aerial vehicle (UAV) data of plan-altitude substantiation and aerial photography were obtained, orthophoto map in WGS84 and MSC coordinate system of the Aksukent settlement territory was obtained. To update the data on existing points of the state geodetic network, complexes of geodetic measurements and calculations were performed and parameters (key) of transformation between WGS84 and WCS coordinate systems were obtained. In the course of the field works, deciphering work was performed based on the obtained orthophoto. The inventory of engineering networks was conducted, which included engineering-geodetic surveys of underground and surface engineering networks (sewerage, water supply, gas supply, heating mains), and engineering-geodetic surveys of overhead and underground cable power lines. The results of the survey of the traces of engineering communications on the territory of Aksukent village were agreed with the balance holders of networks JSC “Turkestan Regional Telecommunications Directorate Kazakhtelecom”, JSC “KazTransGas Aimak”, LLP “Sairam Tazalyk”, LLP “Ontustik Zharyk Transit”. The research is of practical significance, as it contributes to the accurate determination of network parameters, identification of potential problem areas and ensuring effective planning and management of engineering projects.

The use of cable power lines in power supply systems of railways

The use of cable power lines in power supply systems of railways

СИСТЕМИ МОНІТОРИНГУ СУЧАСНИХ КАБЕЛЬНИХ ЛІНІЙ ЕЛЕКТРОПЕРЕДАЧІ

The overview of fiber-optic technologies for real-time monitoring of the technical condition and operational characteristics of modern power cables with cross-linked polyethylene insulation and with the fiber-optic module integrated into their structure is presented. In particular, the new intelligent means for monitoring of the temperature, load current, deformation (mechanical damages), partial discharges in the insulation, moisture penetration inside the cables and control over sheath voltage limitation are described. The topicality of using and developing the technologies of smart diagnostics for power cable lines in order to achieve the effective and safe operation of cables as well as the high reliability of networks is shown. Ref. 47, fig. 7. Key words: power cables, power cable lines, cross-linked polyethylene insulation, integrated fiber-optic modules, power networks, smart monitoring.

Decision support system for power cable insulation vulcanization production line management

The paper proposes a structural model of a decision support system for controlling a cable insulation continuous vulcanization line. The proposed decision support system is based on a mathematical model of the cable insulation continuous vulcanization technological process, a database, and a mode correction algorithm. The DSS will make it possible to quickly develop a new regime in case of using new materials or structures, as well as to correct the current regime in case of unplanned changes during the production process. The core of the DSS is the proposed mathematical model, which is based on conservation laws and is presented as a system of differential equations closed by boundary conditions. The vulcanization process is described taking into account the temperature-time dependence of the kinetic parameters, which made it possible to take into account the uneven heating of the cable, both in the radial direction and along the length. The numerical implementation of the differential mathematical model made it possible to carry out a systematic analysis of the nature of the processes in the vulcanization pipe and to evaluate the influence of various technological, structural and material parameters on the cable insulation vulcanization completion degree. As a result of the analysis, significant parameters were identified that significantly affect the vulcanization process completion degree. Based on the obtained numerical results, technological parameters dependence technological surfaces on the geometry of the product and the properties of the materials used were constructed, a regression mathematical model was proposed that allows determining the values of the process control parameters without resorting to the use of a differential mathematical model. Based on the results of the analysis, an algorithm for correcting the technological regime is proposed, taking into account only significant process parameters. The proposed algorithm allows you to adjust the value of the isolation rate, depending on external influences and deviations from the specified parameters. The results of the study can be used in the production of cable and wire products with vulcanizable insulation, when it is necessary to quickly select the optimal technological mode, take into account changes in the cable design, properties of the insulation material, as well as possible pressure deviations inside the vulcanization pipe.

Device for the Automatic Detection of Fault Locations during High-Voltage Insulation Testing of Power Cable Lines of Electric Power Systems

Device for the Automatic Detection of Fault Locations during High-Voltage Insulation Testing of Power Cable Lines of Electric Power Systems

Особенности моделирования воздушных и кабельных участков линий электропередачи 110–750 кВ при использовании фазного координатного базиса

Power system steady state and transient analysis require correct modeling of overhead transmission lines and cables operating at 110–750 kV. The key difficulties to model sections of overhead and cable lines are caused by complex conductor geometry, their transposition, as well as grounding schemes of ground wires of overhead lines and screens of underground cables. The paper covers various aspects of 110–750 overhead line and cable modeling that must be taken into consideration to obtain a reliable mathematical model in a phase domain. Modern software does not provide a universal solution to determine line parameters. The 110–500 kV cable line modeling issues have not been worked out properly and require careful analysis of specialized foreign literature. Thus, the task to develop the algorithms of calculating the parameters of overhead and cable power lines is relevant, taking into account the various configuration options of these lines which are possible in operational practice. To derive overhead transmission line and cable line models, electric circuit theory and matrix algebra methods have been used. The ATP/ATPDraw and MATLAB/Simulink software environment has been used to investigate what tools are available to determine line parameters, as well as to verify some of the calculation results. Analysis has been carried out to reveal the options available in the ATP/ATPDraw and MATLAB/Simulink software to compute line parameters in a phase domain. An algorithm has been developed and verified to calculate overhead line parameters regardless of the number of parallel circuits. The key features of the calculation of the matrix of linear resistances of overhead power transmission lines are outlined. The main features of modern cable lines operating at 110–500 kV are also described. The paper presents various cable layouts possible in real-field conditions, as well as provides expressions that allow obtaining correct impedances and admittances for a system of cable line conductors. Study of the options of various software tools dedicated to overhead line parameter calculation in a phase domain has revealed that these tools cannot be deemed universal to represent an overhead line of whatever configuration. However, the developed algorithm is universal as it allows computing line parameters regardless the ground wire grounding approach. The expressions presented in this paper consider various layouts of 110–500 kV cable lines that could be encountered in the Russian power system.

ПОТЕНЦІЙНІ ЗАСОБИ ЕКРАНУВАННЯ МАГНІТНОГО ПОЛЯ ПІДЗЕМНИХ СИЛОВИХ КАБЕЛІВ У ПОЛІЕТИЛЕНОВИХ ТРУБАХ З КОМПОЗИЦІЙНОГО МАГНІТНОГО МАТЕРІАЛУ

The magnetic field of the medium- and high-voltage underground power cable line, laid in composite polyethylene pipes having magnetic properties, with the use of special loose-fill/fill-up soil of different dimensions (bulk) is studied by computer modeling. The pipes and additional soils around and near the cables are made of a composite material with effective magnetic properties and can act as a magnetic shield that reduces the level of the field on the ground. The effi-ciency of field shielding depending on the height and width of the composite loose-fill/fill-up soil is analyzed. The exis-tence of the optimal not large (in height) fill-up soil for the best mitigation of the magnetic field on the ground directly above the cables and the influence of the width of the loose-fill/fill-up soils on the shielding efficiency are revealed. The characteristic features of the magnetic field distribution and the field level depending on the availability or non-availability of composite loose-fill soil are presented. The advantages of (trefoil) cable arrangement in one pipe with additional composite loose-fill and fill-up soil are shown. References 30, figures 5.

MODELING AND ANALYZING THE EFFECT OF CONNECTION TO THE NETWORK OF A HARMONIC SOURCE HAVING VARIOUS TOTAL HARMONIC DISTORTION FACTORS ON LOAD SIGNAL WAVEFORMS

This article examines the effect of a network connected source of harmonics having a total harmonic distortion factor varying from 5% to 15% on load voltage and current waveforms. When a source of higher harmonics is connected to the network, both in the network and in the load, the effective values of voltage and current increase, that can negatively affect the cable line insulation, accelerating its destruction and aging.
 To analyze the consequences of a power quality deterioration, a 20 kV network was simulated, consisting of a 20 kV symmetrical generator, an XRUHAKXS-20(1x120/50) power cable line 20 km long, a step-down transformer 20/0.4 kV with a power of 2 MVA, with windings connected in delta-star, and a three-phase symmetrical load.
 The values of the currents flowing through the cable conductor, obtained as the result of simulation were used to calculate the voltage drop between the cable conductor and its shield. Results obtained show that the connection of a harmonic distortion source to a network leads to a magnification of a current flowing through the cable conductor by more than 2%. The model proposed in the article can be used further for a more detailed study of solar photovoltaic plants connection to the grid.
 One of the biggest problems regarding solar power plants is that its electricity generation is intermittent. Thus, future efforts should be focused on modeling and studying the higher harmonics generation during switching on and off of the solar photovoltaic plants.

The device for monitoring the insulation breakdown zone of power cable lines in distribution networks with isolated neutral system during high-voltage diagnostic

The article considers an electrical device designed for diagnostic work in distribution networks of 6-10 kV, namely, the determination of damage zones in case of failure of insulating materials of cable lines during high-voltage diagnostics with a rectified voltage of negative polarity. The novelty of the developed device is its ability to connect directly to a high-voltage cable line without additional matching devices. The device is capable of detecting damage zones in lines up to 10 km remotely with an error of up to 0.2% of the cable length. The prefix allows you to fix any variants of damage to single-phase and three-phase cable lines with high transient resistance at the site of damage without the operation of “burning” insulation, which significantly reduces the time of repair work at the controlled facility.

Study of the Effect of External Magnetic Fields on the Parameters of the Electrical Communications Probing System for a Microtunneling Shield

The issues were reviewed in assessing external electromagnetic fields’ effect on the parameters of an electrical power line probing system based on three-component ferroprobes for detecting active underground power cable lines during microtunnel construction using the thrust boring method (by tunneling shield) in densely populated urban areas. A study was conducted on the change in the topology of the energized cable magnetic field located in the external magnetic field area created by operating electrical equipment under the influence of an external electromagnetic field and a tunneling shield with installed magneto-sensitive detectors. Experimental studies of the probing system were made. Options have been proposed for compensating the inductance component of the external magnetic field during tunnel driving in urban development and industrial area conditions.

УПРАВЛЕНИЕ ПРОПУСКНОЙ СПОСОБНОСТЬЮ ЭНЕРГОСЕТИ В ЗАДАЧАХ ПРОГНОЗИРОВАНИЯ ЭЛЕКТРИЧЕСКОЙ НАГРУЗКИ

The paper considers the software-modeling complex of the power grid management system andits elements. The relevance of the work is due to the requirements of the current legislation for forecastingelectricity consumption to solve the problem of maintaining a balance of capacity betweenthe generating side and electricity consumption. The developed algorithms and control methods areused as part of a software-modeling complex for managing the power grid and power equipment, themost relevant is the use of autonomous consumers and micro-grids in local power systems. For theeffective conduct of experimental research, an experimental methodology was developed, includingthe stage of development of the experimental plan-program; the choice of means of conducting theexperiment; conducting the experiment; processing and analysis of experimental data. It is shownthat it is possible to use the technical and information basis of a hierarchical automated informationmeasuring system for monitoring and accounting of electricity to build a technological managementsystem of a regional grid company. It is shown that the smart meters of the intelligent electricity meteringsystem (ISU) are in continuous communication with the producer and consumer of energy, thatis, monitoring takes place in real time. The developed neural network model (NS) model reduces thetask of short-term forecasting of power consumption to the search for a matrix of free coefficients bytraining on available statistical data (active and reactive power, ambient temperature, date and indexof the day, predictive estimates of power consumption of the forecasting model, some connections, thepower system of the magnitude of the consumed active and reactive power has an acceptable level ofprediction error. A neural network has been developed to estimate the capacity, calculate and predictthe temperature of the cores of a power cable line in real time based on data from the temperaturemonitoring system, and taking into account changes in the current load of the line. The analysis ofthe obtained characteristics showed that the maximum deviation of the data received from the neuralnetwork from the data of the training sample was less than 3%, which is quite an acceptable result.The comparison of the forecast values with the actual ones allows us to speak about the adequacy ofthe chosen network model and its applicability in practice for the reliable operation of the cable systemof power supply to consumers. The analysis of the results showed that the more the insulationmaterial of the power cable line is aged, the greater the temperature difference between the originaland the aged sample.

On the Expediency of Laying Cable Power Lines with a Voltage of 6–35 kV Outside Settlements Instead of Overhead Power Lines

. It is noted that at present, 10 and 35 kV overhead power transmission lines are being laid outside the settlements of the Republic of Belarus on reinforced concrete vibrated (10 kV) and centrifuged (35 kV) poles that are characterized by low reliability and damaging the environment (on account of alienation of land for poles, the need to make a wide clearing for laying in the forest, obstructions by poles and wires of lines to the operation of agricultural machinery, the danger of electric shock to personnel and the public). It is possible to avoid these disadvantages if, instead of overhead lines, power transmission cables with cables insulated by cross-linked polyethylene are used which are characterized by a very low failure flow parameter. Contrary to the prevailing opinion about the higher cost of cable power transmission lines compared to overhead ones of the same rated voltage, it turned out that, taking into account reliability, the cost of electricity lost in the lines for a year, damage to the environment and to the power system caused by the need to perform more expensive emergency repairs (as compared to a planned one), laying cable lines with three-core and single-core cables of a voltage of 10 and 35 kV instead of overhead cables outside the populated area is fairly justified. In this connection, the laying of three-core cables is more preferable. It should be also borne in mind that with an increase in the length of cable lines, the capacitive earth fault current increases, to compensate for which additional devices are needed to be installed in power centers, viz. arc-extinguishing reactors or resistors, accounting for the cost of which (up to 22 % of the cost of one kilometer of cable line) does not significantly affect the conclusions we have drawn regarding the effectiveness of using 6–35 kV cable power lines in an unpopulated area instead of overhead ones, however.

Simulation of an Autonomous DC Electric Power System with Solid-State Transformers

The trends and reasons that stimulate the transition of electric power systems to direct current are considered. The weight, size, energy, and other advantages associated with such transition are shown. A model of an autonomous DC power system constructed on the basis of a gas turbine, high-speed asynchronous generator, and solid-state power transformers is presented, which confirms the operability and feasibility of such system. The results of simulating the start-up of a gas turbine unit, self-excitation of a high-speed asynchronous generator, connection of cable power lines, rheostatic limitation of DC solid-state transformer starting currents, and load surge are presented. A system for automatically stabilizing the voltage at the power line beginning is considered, which is performed by adjusting the gas turbine rotational frequency under the influence of voltage and current feedbacks. A system for stabilizing the load voltage by using a PWM-controlled inverter, which is an integral part of a solid-state DC transformer, is presented.

Methods for the implementation of automatic reclosing on combined overhead and underground cable power lines 110-500 kV

Wydawnictwo SIGMA-NOT wydaje czasopisma fachowe informujące swoich czytelników o najnowszych osiągnięciach naukowych i nowoczesnych rozwiązaniach technicznych w Polsce i na świecie, popularyzuje problemy techniczne oraz poszerza wiedzę i kulturę techniczną.

METHODS FOR MITIGATION OF MAGNETIC FIELD GENERATED BY UNDERGROUND POWER CABLES IN POLYETHYLENE PIPES MADE OF COMPOSITE MAGNETIC MATERIAL

The magnetic field of a high-voltage (330 kV) underground single-circuit power cable line, laid in a polyethylene pipe having magnetic properties, with the use of special loose-fill/fill-up soil of different dimensions (bulk) is studied by computer modeling. The pipe and additional soil around and near the cables are made of a composite material with effective magnetic properties and can act as a magnetic shield that reduces the level of the field on the ground. The efficiency of field shielding depending on the height and width of the composite loose-fill/fill-up soil is analyzed. The existence of the optimal not large (in height) fill-up soil for the best mitigation of the magnetic field on the ground directly above the cables, and the influence of the width of the loose-fill/fill-up soils on the shielding efficiency are revealed. The characteristic features of the magnetic field distribution within the considered shielding elements of the cable line depending on the availability or non-availability of composite loose-fill soil and the height of the fill-up soil with effective magnetic properties are presented. The shielding efficiency of underground single-circuit three-phase power cable lines when using the magnetic fill-up soil with a certain small height (volume) is grounded. References 11, figures 4.

Multi-Modal Sonar Mapping of Offshore Cable Lines with an Autonomous Surface Vehicle

Monitoring offshore infrastructure is a challenging task owing to the harsh ocean environment. To reduce human involvement in this task, this study proposes an autonomous surface vehicle (ASV)-based structural monitoring system for inspecting power cable lines under the ocean surface. The proposed ASV was equipped with multimodal sonar sensors, including a multibeam echosounder (MBES) and side-scan sonar (SSS) for mapping the seafloor, combined with a precisely estimated vehicle pose from navigation sensors. In particular, a globally consistent map was developed using the orthometric height as a vertical datum estimated based on the geoid height received from the GPS. Accordingly, the MBES and SSS generate a map of the target objects in the form of point clouds and sonar images, respectively. Dedicated outlier removal methods for MBES sensing were proposed to preserve the sparse inlier point cloud, and we applied the projection of the SSS image pixels to reflect the geometry of the seafloor. A field test was conducted in an ocean environment using real offshore cable lines to verify the efficiency of the proposed monitoring system.