Cable Operators Research Articles

Regulate drain‐shield relative positioning and contact for mitigating radiated emission from USB cables

AbstractThis letter delves into the influence of drain wire design on electromagnetic radiated emission (RE) from a commercial universal serial bus (USB) cable operating in a high‐speed data transfer mode. The investigation involves an experimental comparison of measured RE across various retrofitted cables. Notably, it is demonstrated that the distribution of contact points on the drain‐shield has negligible effects on RE. Conversely, relocating the drain wire externally to the shields and minimizing the distance with respect to the grounding connector leads to a significant reduction in RE, particularly within the sub‐MHz frequency range. Consequently, regulatory proposals are put forth to diminish overall RE and enhance the RE compliance of USB cables.

Станция подводного обслуживания гибридного необитаемого подводного аппарата системы мониторинга подводного добычного комплекса

The use of support vessels significantly increases the cost of monitoring objects of underwater production complexes (UPC), and the presence of a cable communication line significantly limits the possibility of using remote-controlled uninhabited underwater vehicles (ROV), which is reduced to zero in conditions of continuous ice coverage of the work area. An obvious alternative to the use of ROVs are autonomous uninhabited underwater vehicles (AUVs), equipped with equipment for conducting contact work with monitoring objects and communicating with the shore control post. At the same time, the necessary autonomy for the use of such hybrid autonomous uninhabited underwater vehicles (HAUVs) can be ensured by a network of bottom stations equipped with systems for contactless charging and information exchange with the shore UPC control post. The work proposes the concept of an underwater service station (USS) for a HAUV, which allows, in long-term underwater deployment conditions, to use the device not only in an autonomous mode, but also in a remote control mode from a shore control post. A model for using the station for its intended purpose and the composition of the equipment necessary for its implementation have been determined, the design of the technical solution of the station has been presented, determined taking into account the features of installation on a complex bottom surface and the requirements for docking the HAUV for contactless charging and information exchange, including in the mode of remote control from the SCP. Basic technical solutions for the USS have been developed that provide automatic adjustment of the horizontal position of the docking unit, reliable docking and holding of the HAUV charging and information exchange terminals, and control of the vehicle’s pointing process using a set of rotary video cameras with lamps and a sector-view sonar. Algorithms for interaction between the station and the HAUV have been developed for autonomous and controlled via optical communication cable operating modes of the vehicle.

Image and audio characterization of electromagnetic signals in cable defect detection

Power cables play a very important role in urban development. On the other hand, the integrity and the safe operation of power cables are crucial as even a minor potential mishap can result in serious loss of life and property. Hence, early diagnosis and warning of cable faults are imperative. Addressing the current lack of practical detection technologies, this study proposes a non-destructive testing method based on electromagnetic field principles. Through scanning the power-on power cables with probes, the electric field intensity around the cables can be measured, and the weak anomaly caused by structural and material defects can be detected using Superlets transformation. Additionally, to gain a better characterization of the faults, a digital post-processing approach consisting of imaging and sonification algorithms is developed to aid in pinpointing the location of the faults. Both numerical simulation and experimental test indicate that the proposed non-destructive detection method is feasible and can achieve good accuracy in locating cable faults. With image and audio characterization, the present method has great potential applications in ensuring the safety of power cables.

Automatic constraint programming solver selection method based on machine learning for the cable tree wiring problem

AbstractCable trees are primarily employed in industrial products to facilitate energy transfer and information exchange among various components. When utilizing machines for assembly, it is essential to convert the wiring plan into a sequence of cable insertion operations executed by the machine under various constraints. This poses a combinatorial optimization problem. In this domain, constraint programming (CP) solvers often exhibit outstanding performance by leveraging their robust problem‐modelling capabilities, excellent scalability, and precise solving capabilities. However, CP solvers may achieve various performances for different problem instances. Selecting the most suitable CP solver for each problem instance is crucial. This paper introduces an automatic selection algorithm for CP solvers to solve the cable tree wiring problem (CTW). Firstly, a scoring system is used to conduct an in‐depth analysis and compare four well‐known CP solvers: CPLEX, Chuffed, OR‐Tools, and Gurobi. The results indicate that OR‐Tools and CPLEX outperform other solvers in performance. Moreover, these two solvers exhibit complementary advantages in quickly finding optimal and feasible solutions within specified time limits. Therefore, CP and machine learning are ingeniously integrated, harnessing their complementary advantages. 4240 instances covering various scenarios are randomly generated to form the problem space. This method incorporates decision trees, random forests, K‐nearest neighbours, and naive Bayes, utilizing these four machine learning techniques. The proposed method can achieve better results than traditional single CP solvers. Among all the evaluated machining learning techniques, the automatic solver selection methods based on decision trees and random forests can achieve accuracy rates of 91.29% and 84.15%, respectively.

Research on Temperature Sensing Method for Three-Core Cable Intermediate Joint Considering Three-Phase Load Imbalance

Temperature is a key factor affecting the insulation performance and operation safety of cable joints. Accurate acquisition of hot spot temperatures of cable joints is a difficult issue in cable operation and maintenance. Three-core cables may have unbalanced three-phase loads in actual operation. This paper takes a 10 kV three-core cable joint as the research object; based on the temperature field numerical simulation method, it analyzes the diffusion path of the main heat flow inside the joint and establishes an inversion model that fits the hot spot temperature of the joint through the surface temperature of the cable body. At the same time, considering the special situation of the unbalanced three-phase load of a three-core cable, the joint hot spot temperature inversion model of a three-core cable under an unbalanced three-phase load is further established. This paper further uses the cable joint multi-step unbalanced load temperature rise test to verify the accuracy of the cable joint hot spot temperature inversion model. The maximum error of the transient hot spot temperature inversion does not exceed 4.5 °C, and the steady-state error is within 3 °C. A higher inversion accuracy was achieved. The research results of this article can provide a reference for real-time monitoring of the hot spot temperature of cable joints.

Enterprise culture, neoliberalization, and cable television at the last-mile: A case-study of local cable operators in Mumbai

This paper centers last-mile distribution networks of cable television as a prism to analyze the political-economic, socio-spatial, and subjective transformations brought about by neoliberal reforms in India. I provide an on-ground perspective of enterprise culture and entrepreneurial citizenship based on an ethnography of Mumbai-based last-mile distributors of cable television also called cablewallahs. In the wake of their disempowerment in the television distribution value-chain, cablewallahs represent themselves as entrepreneurs at the core of India’s digital economy. I combine insights from enterprise culture scholarship, television studies and anthropologies of masculinity, to shed light on this enactment in the paper. I demonstrate that cablewallahs configure their citizenship as ‘entrepreneurial’ by aspiring to middle-class valorised notions of respectability and civic duty and sustaining their last-mile networks through intimate knowledge of clientele, networks of male conviviality and vernacular solidarities. I argue that in Mumbai, entrepreneurial citizenship emerges as a useful gendered subjective disposition for navigating socio-economic marginalization and subjective-material changes in neighbourhood identity brought about by neoliberalization.

Simulation Study on Methods for Reducing Dynamic Cable Curvature in Floating Wind Power Platforms

As a key component connecting a floating wind turbine with static sea cables, dynamic cables undergo significant tensile and bending loads caused by hydrostatic pressure, self-weight, waves, and ocean currents during service, which can lead to fatigue failure. Thus, dynamic and fatigue analyses are necessary for the design and operation of dynamic cables. In this study, a fatigue analysis of the three-core four-layer armored dynamic cable used in a semisubmersible floating wind turbine was carried out at a water depth of 25 m. The Miner linear cumulative damage method, based on material S-N curves, was used to predict fatigue life. The results indicate that, at 10 times the safety factor, the dynamic cables meet the design requirement of a 30-year service life in the studied marine environment. The maximal curvature of the dynamic cable always appears at the exit of the bend stiffener, even beyond the allowed point. Adding weights to the section where the cable exits the bend stiffener and adjusting the bend stiffener’s hanging angle can both reduce the curvature at the bend stiffener exit. The scheme of adjusting the bend stiffener’s hanging angle is preferred, for it is easier for simultaneous adjusting and inducing much smaller extra stress in the cable. As the hanging angle increases, the curvature at the bend stiffener exit decreases, while the maximal effective tension and maximal von Mises stress gradually increase. For certain operating conditions, especially with higher waves, it is better to adjust the hanging angle to avoid excessive curvature and, meanwhile, ensure the increase in the stress within a reasonable range.

A Simulation Study of Noise Exposure in Sledge-Based Cable Yarding Operations

Ensuring the safety of forestry workers is a key challenge, particularly when working with partly mechanized harvesting systems. Cable yarding is typically used in steep terrain timber harvesting. For long-distance extraction, one of the few alternatives is to use sledge yarders, but these machines may expose workers to high doses of noise. The goal of this study was to model haulers’ exposure to noise in sledge-based cable yarding operations, based on a simulation approach that considered variable factors such as the yarding distance, lateral yarding distance, and average skyline height. Taken into consideration were 165 scenarios developed by examining the variation in yarding distance (500 to 1500 m, with a step of 100 m), lateral yarding distance (10 to 50 m, with a step of 10 m), and average skyline height above the ground (10, 15, and 20 m). The simulations assumed an 8-h working day with a break of 1 h. The models and statistics published by other studies were used to calculate the time consumption and number of work cycles completed within a working day. These data were used to compute the equivalent exposure to noise (LAeq) for each scenario, as well as for those work elements that were likely to expose the haulers to noise the most. The presented findings indicated that (i) the exposure to noise was higher than 100 dB(A), irrespective of variation in the considered factors; (ii) the trend in exposure was characterized by polynomials in relation to the extraction distance, and the magnitude of exposure was consistently affected by variation in the considered factors; and (iii) without hearing protection, the empty and loaded turns exposed workers to noise over the permissible limits. These findings strongly suggest the use of hearing protection when working in close proximity to sledge-based cable yarding operations. The methods proposed in this study in the form of simulation may help benchmark other forest operations.

Method of calculation of temperature parameters and service life of 10 kv cable lines

This study is based on the analysis of the methodology for calculating the temperature parameters of 10 kV cable lines and calculating the service life of insulation under various operating conditions, as well as identifying dependencies that allow the most accurate selection of cable parameters during operation at industrial facilities. The results of the study can be used to improve the energy efficiency of enterprises, and contribute to reducing the number of emergency failures of cable lines that may occur due to thermal breakdowns caused by incorrect choice of cable parameters under certain operating conditions, which may cause an increase in production costs in general. Conducting research and calculations of temperature parameters of cable lines at a voltage of 10 kV with different laying methods and with different capacity factors according to the climatology of the Republic of Tatarstan, as well as identifying key dependencies that will enable to draw appropriate conclusions on the operation of cables in the conditions under consideration. The article uses methods for calculating temperature parameters and cable service life, as well as methods for processing the data obtained as a result of calculations, including the method of function approximation. Special software is also used to visualize the results obtained after the calculations. The results of calculations of temperature parameters of 10 kV cable lines for various laying methods, with different types of insulation and with different capacity factors according to climatology of the Republic of Tatarstan are presented. Calculations of the service life of cable lines under the conditions under study have been made and conclusions have been drawn on optimal cable loads that will not lead to premature thermal aging of insulation under certain operating conditions. The initial data for the calculations and the methodology used comply with GOST standards for cable lines. The results of the study and the calculations performed can be used to evaluate and select the optimal load of cable lines under selected conditions at the design stage of power supply systems.

A Cable Knot and BPS-Series II

This is a companion paper to earlier work of the author, which generalizes to an infinite family of -cabling of the figure eight knot () and proposes general formulas for the two-variable series invariant of the family of the cable knots. The formulas provide an insight into the cabling operation. We verify the conjecture through explicit examples using the recursion method, which also provide a strong evidence for the q-holonomic property of the series invariant. This result paves a road for computation of the WRT invariant of a 3-manifold obtained from a Dehn surgery on the cable knots via a certain q-series. We also analyze and conjecture formulas for -cabling ().

The warning and security system of the multifunctional complex

This article describes the warning and security system in the building of a multifunctional complex located in the city of Rostov-on-Don. The project includes the positioning of radio and telephone equipment, the installation of an Internet transmission network, as well as an alarm system for the entire building. The building must be a subscriber in order to gain access to one of the Internet networks and cable operators that can connect the transmitted object and the Internet. A radio network and a telephone network have been designed, as well as the reception of radio waves has been provided. A bell alarm system of the building is provided and installed. There are many different public multifunctional buildings in Rostov-on-Don, but there was a clear shortage of it in this area of the city. Moreover, this facility is distinguished by the fact that it has not only the usual shopping and entertainment areas for the city, but also a business space, which is now very much in short supply to many, as work at home and online is gaining more and more momentum.

Numerical modeling and fatigue analysis of the dynamic response of main pump cable in nuclear power plant

Abstract The structural temperature rise and thermal stress caused by operation current and ambient temperature are some of the main factors affecting cable fatigue life. Combined with the operating and environmental conditions of the main cooling pump of the nuclear power plant, the thermal-structural coupling field numerical modeling and fatigue analysis of the 6kV single-core and three-core cable of the main pump is carried out. Based on obtaining the steady-state operating current, the motor start-up transient current, and the circulating ambient temperature, the thermal-structural coupling field numerical model of the main pump cable is established using the load transfer method to obtain the thermal and stress field distribution of the internal structural layer. The load history of one cycle is extracted for the fatigue numerical simulation of the main pump cable. The stress time history of the cable structure layer was constructed by the stress calculation results and the load time history of a single period, and the fatigue life of the main pump cable was obtained based on the S-N curve of the main insulation material and the Miner’s linear cumulative damage theory. The simulation results show that the force acting on the main pump cable by the operating current and ambient temperature is an approximately symmetric cyclic load of constant amplitude. The life cycle of the cable can reach 2.235*e4 times, and the overall life of the cable is about 63.97 years. This study can provide theoretical guidance for the safety and reliability design and state operation and maintenance of the main pump cable of the nuclear power plant.

Application Research on Online Power Cable Temperature Detection via Fiber Optics

Abstract Power cable conductor ampacity directly correlates with conductor temperature. Traditional thermocouple measurement fails to ensure real-time monitoring, risking cable operation. Leveraging Raman scattering principles, this study establishes a method for continuous surface temperature detection of long-distance power cables using distributed fiber optics. This approach surpasses OTDR-based measurement in speed and reliability, offering superior online monitoring for cable systems, suitable for widespread adoption.

Analysis of Power Distribution Wiring and Cable Operation Techniques

Analysis of Power Distribution Wiring and Cable Operation Techniques

Productivity Analysis of Mid-Size Cable Yarding Operation based on UAV-captured Video Sequences

Cable yarding is one of the most preferred timber extraction methods in steep and mountainous terrain conditions. In recent years in Turkiye, mid-size cable yarders have begun to be used frequently in steep forest areas where intensive forestry is carried out. In order to make more effective use of cable yarders and achieve maximum productivity, timber extraction operations must be planned most appropriately and implemented in the field accordingly. The productivity of mechanized equipment used in harvesting operations is mainly determined by using time study analysis. In traditional methods, time measurements are carried out by observing the work stages with time recording devices (stopwatches) in the area where the machine operates. Since timber extraction by using a cable yarder occur in steep and rugged terrain conditions, difficulties may be encountered in applying time analysis in the field. In this study, it was aimed to obtain high-resolution digital video images of the activities of cable yarding operation with an Unmanned Aerial Vehicle (UAV) and to calculate productivity through time study analysis on these images. For the study, the Tajfun MOZ 500 GR model mid-size cable yarder was evaluated during a timber extraction operation in Köyceğiz Forest Enterprise Chief (FEC), located in Muğla City, Turkiye. Besides, statistical analysis was performed to estimate the effects of factors such as average product length, product diameter, lateral yarding distance, number of pieces, and total product volume per turn on the productivity of the cable yarder. The results indicated that UAV video images can be an effective alternative method to conduct time study analysis and productivity estimations. It was found that the productivity of the mid-size cable yarder was 11.76 m3/hour. During the operation, the pulling mainline to the product and choker setting were the most time-consuming work stages, followed by the time-loaded carriage reaching the landing. The statistical analysis indicated a significant relationship (p<0.001) between product length, product diameter, total volume and productivity of the cable yarder. The results showed that there was a negative relationship between lateral yarding distance and productivity. The regression model regarding the productivity of the cable yarder and the independent variables was also significant.

Effect of nucleating agents on the electrical properties of cross‐linked polyethylene under tensile stress

AbstractDuring the operation of high‐voltage cables, external stress and residual stress can affect the aggregated structure of insulating materials and lead to significant deterioration in their electrical performance. To investigate the evolution characteristics of the electrical properties of cross‐linked polyethylene (XLPE) under mechanical stress, this paper explains the relationship between the aggregated structure of XLPE and its electrical properties and proposes a method for improving insulation performance under mechanical stress. The results show that metallocene polyethylene used as a nucleating agent can promote crystallisation through heterogeneous nucleation and increase Young's modulus by non‐uniform nucleation, increasing crystallinity and reducing interplanar spacing, resulting in more complete crystal forms and reduced damage to the aggregated structure during the tensile process. After nucleating agent modification, the XLPE crystallisation becomes more uniform, and interfacial adhesion forces increase. The weakened interface damage process between the amorphous and crystalline regions under tensile stress effectively inhibits the process of molecular chain polarisation turning and reduces trap density. The modified XLPE crystal structure shows a tendency towards densification and enhanced molecular chain interactions, which can reduce the damage to the aggregated structure under tensile stress, while the reduced free volume inside the material and the shortened average free path of carriers can weaken the damage of high‐energy electrons to molecular chains, thereby inhibiting the process of electrical tree degradation. The results show that nucleating agents have great potential for maintaining the stable operation of XLPE cables under mechanical stress.

Temperature mapping model of cables considering the coupling of electromagnetic and thermal field

Background During cable operation, its internal temperature reflects the actual working condition of the cable. Once overload occurs, its conductor temperature will rise rapidly. Under high temperature conditions, the insulation material is very prone to breakdown accidents, which seriously threatens the safety of the power system. The traditional method of calculating the internal temperature of cables suffers from low accuracy and time-consuming problems. Methods To quickly and accurately calculate the cable’s internal temperature, a cable temperature mapping model is proposed with the coupling of electromagnetic and thermal field taken into consideration. Firstly, a finite element model is formulated based on the cable structure and material parameters. Secondly, the coupling between electromagnetic and thermal field is analyzed, and multiple coupling calculations are performed iteratively according to the operating conditions. Finally, the mapping between temperature and current is established using the exponential function. The cable surface temperatures under five operating conditions are measured online and compared with the calculated results of the temperature mapping model. Results Under five operating conditions, the average absolute error of the proposed model is 0.628 °C, and the average calculation time is 0.005 s. The average absolute error of the traditional model is 0.635 °C, and the average calculation time is 201.86 s. Conclusions The temperature mapping model developed in this paper can quickly and accurately calculate the cable’s internal temperature and forms an important part of the digital twin model of the cable.

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.

Regulating the structure of crosslinked polyethylene and its application in ultra‐high voltage cables

AbstractThe crystallinity of polyethylene has been extensively studied, but in situ experiments designed to investigate the crystallization of PE and XLPE have hardly been discussed. In this work, the crystallization behavior of PE and XLPE was investigated by designing in situ crystallization observation experiments. We have compared the crystallinity, crosslinking, viscosity properties, and gas byproducts of different XLPE insulating materials. COMSOL simulations demonstrate that the DTAP and DTBP crosslinker initiated crosslinks have better insulating properties and cable stability than the DTBC and DTBTMC crosslinkers. The formation of an insulation layer initiated by the DTAP crosslinker is beneficial for improving the breakdown strength, processing performance, and stable operation of cables. Our work is of great significance for understanding the crystallinity of XLPE and determining the correct crosslinker.Highlights In situ crystallization observation of PE and XLPE. Simulation of ultra‐high voltage cables. Finite element analysis. Investigation of gas byproducts in XLPE.

Experimental Study on Electromagnetic Interference on control cable from two unbalanced 10 kV Power Cables

The occurrence of unpredicted and sudden failures in power cables seriously threatened the nearby control cables. Two cases of unbalance in the three-phase current load originate from a high horsepower pump and a sudden power off in an MW pump, resulting in an error signal detected in the adjacent control cable. However, these two cases just occurred once during the plant operation; no more history records can be a reference. In this paper, a typical power cable and control cable structure was constructed, typical accidents in power cables were considered, and electromagnetic interference was considered. The results show that the unbalance of the three-phase load results in a fold increase in interference current. Compared with the two-phase unbalance, the one-phase would bring a higher current. In other words, power off in a sudden situation brought a higher current than three-phase unbalance, especially a faster drop in current load. Finally, more attention should be given to the power cable operation, including unbalance in the power cable and an urgent power off.