Cable Installation Research Articles

Sistem Monitoring Kebocoran Gas SF6 Pada Sistem GIS menggunakan Modul LoRa Berbasis IoT

The research introduces a Gas Insulating Substation (GIS) Monitoring System for SF6 gas leakage, aiming to mitigate the risk of significant gas leaks. The GIS, comprising three phases (R, S, T), utilizes SF6 gas with protective alarms and leakage indicators on each phase. However, the current practice of sequentially checking leak points among phases poses challenges, such as potential damage to the SF6 gas refill valve, leading to larger leaks. In response, a Monitoring System using LoRa-based IoT modules was developed. The research methodology involved checking electrical flow through voltage sensors and pressure sensors on the nonferrous tubes of the three phases to identify leakage points. The results indicated that the implemented SF6 Gas Leakage Monitoring System using LoRa-based IoT Modules effectively assists High Voltage Substation operators in reducing valve damage caused by mishandling SF6 gas leaks. Operators can monitor leaky tubes through a web interface and receive Telegram notifications, expediting response times. Additionally, the system proves cost-effective, requiring only around 1 million rupiahs compared to the conventional cable installation costing approximately 5 million rupiahs, without necessitating modifications to the existing Substation system.

Drivers of black grouse trends in the French Alps: The prevailing contribution of climate

AbstractAimMountains host complex ecosystems whose wide range of ecological conditions over small geographical distances makes them biodiversity hotspots. To ensure their long‐term conservation, a better understanding of the interaction between climate change and modifications in land use is necessary. Most studies have focused on only one of these factors at a time, leading to incomplete predictions. In this study, we explored the relative contribution of both recreative activities and climate change on the population dynamics of the black grouse (Tetraotetrix), an emblematic cold‐adapted species of the Alps.MethodsWe used data from a network of 47 monitoring sites dispersed around the French Alps and surveyed since the 1980s or 1990s. We estimated black grouse population growth rates using state‐space models and tested for effects of biotic and abiotic pressures on both long‐term trends and inter‐annual variations in these rates.ResultsPopulation trajectories were strongly heterogeneous in space; nevertheless, a general decline at the edge of the black grouse distribution area was revealed in the southern pre‐Alps. We found very little influence of hunting and new ski lift cables installation on inter‐annual variability in population growth rate. In contrast, our results suggest strong impact of climatic conditions and phenology. While temperature positively influenced growth rate, precipitation had a negative effect. Early snowmelt and vegetation season were correlated with high positive values of annual population growth rates.Main conclusionsBirds in mountain habitats may be drastically affected by ongoing climate change, perhaps to a greater extent than by an increase in recreational activities. However, other human activities in the mountains (such as animal grazing or forest exploitation) that were not taken into consideration in this study might also have a strong impact on habitat structure and indirectly affect populations’ growth.

ANALYSIS OF THE WHOLE-PROCESS MECHANICAL RESPONSE OF TUNNEL SURROUNDING ROCK UNDER THE EFFECT OF ANCHORAGE SYSTEM

The tunnel anchoring system is an important means to control the deformation of surrounding rock, whose scientific design lies in the full understanding of its mechanism. In this paper, the whole process of the response of tunnel surrounding rock with the action of the anchorage system is analyzed. Based on the space effect of the tunnel face, the displacement releases of surrounding rock at bolt and anchor cable installation and the effect of their relative lengths are considered. According to the relationship between the anchorage zone and the plastic zone of the interaction between the anchorage system and the surrounding rock, six mechanical analytical models of the whole process evolution mechanism of anchorage system are proposed and analyzed respectively. The solutions of tunnel deformation, plastic radius and stress field of surrounding rock under the action of anchoring system are obtained. The correctness and reliability of the proposed model are verified through a comparison with numerical simulations using typical examples. Furthermore, the deformation control effect of the anchorage system and its influencing factors are analyzed, and the respective tasks and objectives of rockbolts and anchor cables are defined. The safety reserve function of anchor cable is clarified, giving a new understanding of deformation control principle of anchorage system. The research results lay a theoretical foundation for the quantitative design of tunnel anchorage system and provide a new idea for the control of deformation of tunnel surrounding rock.

A call to assess the impacts of electromagnetic fields from subsea cables on the movement ecology of marine migrants

AbstractThe number of subsea cables in the marine environment is likely to grow substantially in the near future. Arrays of energy‐generating windmills or wave power generators are planned for installation in the coastal waters of many countries worldwide. The electricity generated by these and other marine energy sources will be transported to shore through cables with the current and voltage creating electromagnetic fields (EMFs). Furthermore, there are also plans for the installation of undersea cables to interconnect countries and islands for the purpose of sharing power and communications. These also will generate EMFs in the marine environment. While shielding can negate the presence of direct electric fields, induced electric and magnetic fields readily penetrate into the water column. Cables carrying electric current produce anomalies in the earth's main field, which could have the potential for disrupting the migrations of fishes and diverse marine animals that rely on magnetic cues for orientation or navigation. Studies designed to test how these anthropogenic magnetic fields disrupt magnetic orientation have only recently started to be conducted. Given the cultural, economic, and conservation value of many of the species potentially at risk, such work should be immediately prioritized.

Experimental study and modelling of the thermal conductivity of frozen sandy soil at different water contents

In a wide range of earthworks and engineering applications such as ground heat exchanger piles and energy piles, radioactive waste disposal in deep underground locations, installation of underground power cables, etc., a better understanding of soil thermal conductivity is required in cold regions. The thermal conductivity (λ) of frozen sandy soils in eastern Turkey was measured for five volumetric water contents (θ = 0.219, 0.230, 0.246, 0.260, and 0.320 m3/ m3) at six frozen temperatures (Tf = 4, 0, −7, −12, −20 and −25 °C). Moreover, six proposed models were analyzed to determine the λ. The results demonstrated that a decrease in the Tf increased the λ and reached a plateau at a very low Tf for all θ. Increasing the θ increases the λ at the same Tf. Also, the de Vries model provided for the highest precision, followed by the Chen, the Parallel, the Johansen, the Cote and Konrad, and the serial models, respectively. Further, the changes of volume in the soil were incorporated into the parallel and series models, and a new model was developed to estimate the λ of the frozen soil. The new model can be effectively used to estimate the λ.

Evaluasi Keselamatan Kerja Listrik Laboratorium Permesinan Kapal Universitas Maritim AMNI Semarang Dengan Metode Analitycal Network Process (ANP)

In the operation of electrical components in the ship engineering laboratory of the Maritime University of AMNI Semarang, various kinds of protection are needed. Errors in installing and operating electrical equipment can reduce protection. This protection aims to improve the safety of electrical work in ship engineering laboratories. And in the application of electrical work safety, it is necessary to evaluate based on the 2000 Electrical Installation General Requirements standard (PUILL 2000). The purpose of this study was to evaluate the use of the laboratory of the Maritime University of AMNI Semarang in the aspect of work safety. Based on the results of the evaluation, the criteria for electrical work safety are determined, namely: protection for safety, protection from overvoltages and currents, protection from thermal effects, and protection from fault currents. After the evaluation was carried out, alternatives were found to improve electrical safety: standard operating procedure (SOP), an inspection of cable installations, checking MCB panels and switches. The criteria and alternatives obtained then processed using the software super decision ver.2.10.0 with the Analytical Network Process (ANP) method so that the priority results of electrical safety improvements in the ship engineering laboratory of AMNI Maritime University Semarang are: repair of SOP 63.7%, cable installation 25.8%, MCB panel, and 10.5% switch.

Usage of Cable Bolts for Gateroad Maintenance in Soft Rocks

Purpose This paper analyses the effectiveness of gateroad reinforcing by means of cable bolts under weak rock conditions. In the worldwide mining industry the method of gateroad support reinforcement using cable bolts is considered to be effective. The experimental application of cable bolts was performed in gateroad #165 of the "Stepova" mine, Western Donbass, Ukraine, and required instrumental control of "support-rock mass" system conditions. Methods Obtaining absolute displacement of "support-rock mass" system elements and extensometer anchors by means of levelling in order to improve the method of observation. Results The peculiarities of geomechanical behaviour of rock mass in the roof of gateroads is investigated. It has been established that the application of cable bolts allows for a reduction in the vertical convergence of the gateroad, both in front of and behind the longwall face. Practical implications Advantages of cable bolts instead of end-face support and props in case of a high advance rate of the longwall face are shown. Originality/value 1. There are no regulations and state standards in regard to cable bolt installation parameters in the mines of Ukraine, consequently the usage of cable bolts for gateroad maintenance required preliminary testing under geological conditions at the Western Donbass mines with soft enclosing rocks. 2. Combining levelling with observations using extensometers allowed for the detection of the rock layers' uniform sagging zone in the roof of the gateroad.

Usage of Cable Bolts for Gateroad Maintenance in Soft Rocks

Purpose This paper analyses the effectiveness of gateroad reinforcing by means of cable bolts under weak rock conditions. In the worldwide mining industry the method of gateroad support reinforcement using cable bolts is considered to be effective. The experimental application of cable bolts was performed in gateroad #165 of the "Stepova" mine, Western Donbass, Ukraine, and required instrumental control of "support-rock mass" system conditions. Methods Obtaining absolute displacement of "support-rock mass" system elements and extensometer anchors by means of levelling in order to improve the method of observation. Results The peculiarities of geomechanical behaviour of rock mass in the roof of gateroads is investigated. It has been established that the application of cable bolts allows for a reduction in the vertical convergence of the gateroad, both in front of and behind the longwall face. Practical implications Advantages of cable bolts instead of end-face support and props in case of a high advance rate of the longwall face are shown. Originality/value 1. There are no regulations and state standards in regard to cable bolt installation parameters in the mines of Ukraine, consequently the usage of cable bolts for gateroad maintenance required preliminary testing under geological conditions at the Western Donbass mines with soft enclosing rocks. 2. Combining levelling with observations using extensometers allowed for the detection of the rock layers' uniform sagging zone in the roof of the gateroad.

Analysis on the structural type of large-span steel truss bridge specially designed for cables

When the installation of cables and pipelines needs to go across rivers, bridges are usually adopted to support the cables and pipelines for crossing the rivers. The measure can make full use of the space resources and have no effect on the flow pattern of rivers. For this reason, analysis on the structural-type design of a large-span steel truss bridge specially used for cables has been performed. The numerical results indicate that the stayed-cable bridge with steel truss beam and concrete main tower has better performance and improved structural type caparisoned with that of the beam and arch bridges, and the construction of the major beam can be without the temporary support.

Wind-Induced Vibration Control of High-Rise Structures Using Compound Damping Cables

Based on the vibration reduction mechanism of compound damping cables, this study focuses on the wind-induced vibration control of high-rise structures with additional mass at the top. The differential equation of motion of the system under the action of the composite damping cable is established, and the analytical solution of the additional damping ratio of the structure is deduced, which is verified by model tests. The vibration response of the structure under the action of simple harmonic vortex excitation and randomly fluctuating wind loads is studied, and the effect of different viscous coefficients of the dampers in the composite damping cable and different installation heights of the damping cable on the vibration control is analyzed. The results show that a small vortex excitation force will cause large vibrations of low-dampened towering structures, and the structure will undergo buffeting under the action of wind load pulse force. The damping cable can greatly reduce the amplitude of structural vibration. The root means square of structural vibration displacement varies with damping. The viscosity coefficient of the device and the installation height of the main cable of the damping cable are greatly reduced.

Onshore wind farm - Reliability centered cable routing

Designing an onshore wind farm is a complex planning process that requires various stages to be completed. The prime focus of this work is to assist planners and experts in finding the optimal cable layout of the onshore wind farm. The optimization algorithm is designed using mixed integer linear programming (MILP). The MILP algorithm takes into account system reliability, power transfer capacities and power quality issue. The novelty in this optimization algorithm is to simultaneously minimize cable installation cost and the cost of lost energy production and therefore maximize the reliability of the system. Additionally, the algorithm supports the optimal selection among different cable options, with different features, prices and capacities. By calculating voltage increase at the point of connection (POC), power quality issue is considered as well. The designed algorithm provides optimal results for four different wind farm layouts. Every layout is tested for three different case scenarios, where different number and type of cables are considered. The results show that more cable options contribute in lowering the total costs. Moreover, cables with higher capacity can help in improving the power quality issue.

Penerapan Six Sigma untuk Peningkatan Kualitas Jasa Layanan IndiHome

The development of the broadband internet access business is getting tighter these days, encouraging companies to prioritize service quality to achieve predetermined goals and objectives. IndiHome service is one of the internet access services from PT Telekomunikasi Indonesia whose access network is managed by PT Telkom Akses. PT Telkom Akses is Telkom's commitment to continue to develop unlimited broadband networks for all Indonesian people. Based on the data, there are 10.751 IndiHome services that are disrupted, with the results of the analysis using the Six Sigma method, it is known that the sigma level is 3.90 with the possibility of service being interrupted by 8,696 in a million possibilities, there are three potential Critical to Quality potentials, namely Disconnected Outdoor Cables (47,29%), Defective Splitters (31,84%), and Home Cable Installation (20,87%).

Two-stage stochastic programming formulation for optimal design and operation of multi-microgrid system using data-based modeling of renewable energy sources

Microgrid (MG) is intended to accommodate distributed renewable energy sources and manage the generated electricity using a dispatch and storage system to satisfy the demand of a local region over time. Main challenges associated with operating such a system stems primarily from the intermittent and uncertain nature of renewable energy sources causing the energy generation to be highly irregular and less predictable. Multi-microgrid (MMG) systems with flexibility to trade energy between individual MGs can alleviate the demand–supply mismatch problem, but its design and operation become more complicated. Previous studies on MMGs addressed only the case where all the MGs are fully connected to share electricity. However, the installation of electric cable connections over the full network can be costly and is often unjustified. To address the question of how to best achieve a tradeoff, this work proposes the use of a two-stage stochastic decision-making approach for designing and operating an MMG considering both the capital cost for installing the electric cables and operating cost. First, real weather data are used to develop stochastic models that describe the uncertain, intermittent nature of energy production through renewable sources over a day. Then, in the first stage, design-level decisions regarding the installation of the electric cable between individual pairs of the MGs are to be determined to achieve the best tradeoff for the modeled system and weather pattern. In the second stage, the optimal energy dispatch planning for each individual MG including the energy trading between the MGs is carried out based on a particular realized scenario of the renewable energy production.

Heat Dissipation Test With Fiber‐Optic Distributed Temperature Sensing to Estimate Groundwater Flux

AbstractWe measure groundwater flux and thermal parameters around a borehole performing a heat dissipation test by heating the armor of a single fiber‐optic cable and interpreting the resulting heating curves with a new analytical method. The procedure is similar to thermal response tests, but benefitting from the high spatial and temporal resolution of distributed temperature sensing and lasting longer, so as to measure advective dissipation. Field installation relies on an innovative method in hydrogeology, which is based on the installation of the FO cable in the annular space of the well, close to the aquifer matrix. The proposed new analytical method, expands the traditional Moving Infinitesimal Line Source Model to account for the effects of the field set up and cable materials. In fact, we show that the resulting temperature build‐up goes through four periods easy to identify using the log derivative of temperature (dT/d (ln(t))): Initial response, skin (cable insulation), conduction dominated and advection dominated. We test the proposed method in an unconsolidated shallow aquifer with controlled pumping. Results are of the same order of magnitude of independent estimates of groundwater velocity.

Study of Development & Application about Assembly Technology of Optical Fiber in High-capacity Satellite

This article proposed a method for final assembly of optical fiber cables based on the needs of satellite installation of optical fiber cables, the structural features of optical fiber cables, and on the basis of fully demonstrating the installation conditions of optical fiber cables. The articles also analyzed factors that affect the quality of the final assembly of optical fiber cables based on the rationality of wiring and the effectiveness of cable protection and the reliability of electrical connector insertion. The method proposed by the article greatly improves the assembly efficiency while effectively ensuring the safety and reliability of the final assembly of the product.

Development and application of an internet of things door lock Network Bridge for classroom access control management

School classroom doors are usually managed using conventional machine locks. This can cause inconvenience for the borrowing and returning of keys. In addition, issues on the copying and embezzlement of keys are persistent. To avoid these problems, schools have replaced conventional locks with card readers and magnetic locks to manage classroom access; users need only a RFID card to enter and exit classrooms. However, the hardware and software equipment required for such control schemes is expensive and entails cumbersome installation processes. This study developed an innovative Internet of Things (IoT) door lock network bridge, which can be installed on conventional electronic locks to transform it into IoT locks. The developed bridge can be integrated with a customized web-based classroom access information system and QR code scanning to establish a low-cost classroom access control system. The system can be provided to schools to perform user management, lock management, and lock matching. Each door in the school is assigned with a unique QR code for unlocking. Users only need to use the QR code scanner on their smart phone to send relevant information required for unlocking a door to the web-based classroom access information system, which then performs user and lock matching verification. Verified users can then unlock the door and enter the venue. The proposed classroom access control system does not require card readers or RFID cards. The cable installation of the system is simplified through by using wireless connections, thereby greatly reducing the time, cost, and human resource required for installation. In addition, users and locks can be matched directly using the proposed system. This greatly improves the convenience of classroom management in schools.

Study on Mechanical Properties and Application of a New Flexible Bolt

As mining depth extends continuously, complex geological environment and strong mining stress pose serious challenges against excavation safety and higher demand for bolt support. To meet the challenges, a new type of flexible bolt is developed that is free from the limitation of excavation height and can be installed quickly. The flexible bolts have a tail structure which is squeezed together by the locking casing and the steel-strand rod. The tail structure forms the thread through the rolling process, and then can be quickly installed by the nut rotation type, which avoids the disadvantages of the cable tension installation. Through the flexible long bolts, the thick anchoring layer of the roof can be constructed, and the safety control of the roadway is realized. To obtain the optimal specifications, locking casings of three diameters and lengths were used to prepare bolt samples for static tensile test. Test results show that when the diameter of locking casing is fixed, the peak resistance increases as the length of locking casing increases, but the increased amplitude tends to reduce gradually. When the length of locking casing is fixed, too large a diameter makes the mechanical property unstable. Finally, the optimal length and diameter of locking casing are set at 120 and 30 mm, respectively. In addition, cyclic loading tests were conducted, the results of which indicate that cyclic loading does not change the stress state within the bolts and that flexible bolts display a stable mechanical property. Field results indicate that flexible bolts achieve low damage of the surrounding rock and control the maximum roof fracture depth within 2.1 m, thus guaranteeing the roadway safety.

Installation of submarine cables and pipes in shallow waters and connecting them to the shore by the method of horizontal directional drilling

This article presents the horizontal directional drilling (HDD) as one of the most suitable technique used to reduce the impact on the environment during the submarine pipe and cable installation process, especially in the coastal area and shallow waters. HDD is a technique used to drill a subsea tunnel or under other designated area with the goal to pull a pipe or other facility through the drilled underground tunnel. With the development of the offshore natural gas and wind industry, the demand for the construction of transfer pipeline and cables has also increased. The installation of submarine pipelines and cables can have negative effects on the marine environment. This is one of the main reasons that construction and operation of offshore wind energy systems has been and continues to be regarded with scepticism by environmental activists, despite the undeniable benefits of this renewable energy source. The main objectives of this article are to emphasize the importance of using this technique but also to highlight the benefits, in particular by significantly reducing the impact on the marine environment.

INSTALLATION OF SUBMARINE CABLES IN THE OFFSHORE WIND INDUSTRY AND THEIR IMPACT ON THE MARINE ENVIRONMENT

"This article presents the main methods of installing submarine cables used in the offshore wind industry and the impact they have on the marine environment. From this article, the reader will be able to understand the basic principles that are taken into account from the design phase of a submarine cable, principles that seek to streamline their installation, operation and maintenance and their impact on the marine environment. Given the scale of the development of the wind industry, especially offshore, the length of submarine cables that provide energy transport from the wind farm to shore consumers is also constantly growing. The construction and operation of offshore wind energy systems has been and continues to be regarded with scepticism by environmental activists. Despite the undeniable benefits of this renewable energy source, the impact on the marine environment must also be taken into consideration. We studied the most efficient methods of installing submarine cables in the offshore wind industry – study which also includes analysing the behaviour of submarine cables and analysing ships’ movement during cable transport and installation. This article is only part of a major research on the installation of submarine cables in the offshore wind industry. In terms of the frequency and relatively short duration of submarine cable installation operations, on a small strip of up to 8m, the disturbances and impact caused by these operations are considered minor and are preferred compared to bottom trawling operations and dredging, which are repetitive and more extensive. A single impact, such as cable burial operations, is preferred to continuous, multiple or recurrent impacts. [1] "

Effect of Tensile Stress on Characteristics of High-Temperature Superconducting Tape

With the discovery of high-temperature superconducting (HTS) tape and the improvement of the performance of the second-generation HTS tape, the application of superconductors in power system is gradually unfolding. There have been many demonstration projects at home and abroad. When the HTS tape is applied to the power cable, the mechanical external action of the cable winding, laying and installation operations, and the Ampere force when the current is applied are applied to it. Stress has an important influence on the critical current characteristic of the superconducting tape. In different application scenarios of the tape, different materials and thicknesses reinforcement layers can be chosen. In this paper, for the YBCO superconducting tapes with different reinforcement layers, a set of systems with critical current under tensile stress at cryogenic temperature is used to study the influence of tensile stress on the critical current of superconducting tape at low temperature. We analyze the influence of the structure of the superconducting tape on the characteristics of the tape and studied its degradation characteristics, which have guiding significance for the design and operation of the superconducting cable.