Transmission Cables Research Articles

GSM Based of Unclad Fibre Temperature Sensor for Electrical Transmission Cable Monitoring System

This paper presents a temperature monitoring system for an electrical transmission cable utilizing a global mobile service (GSM)-based unclad fibre sensor. The developed system consists of GSM module, Arduino controller, unclad plastic optical fibre (POF) sensor, light emitting diode (LED) and photodetector. The unclad POF sensor was chosen due to its immunity towards electromagnetic interference as well as its high sensitivity performance. In this work, the transmission cable hazardous temperature is set at 70oC, which is the maximum operating temperature value provided by the National Electrical Code (NEC) NFPA 70. For system characterization, temperature of the cable was varied from 30oC to 70oC. Photodetector output voltage for this temperature variation were recorded at 660 nm and 770 nm operating wavelength. The recorded data shows that the sensor sensitivity performances at 660 nm wavelength are found superior than 770 nm wavelength, which are 0.9710mV/oC and 0.9699mV/oC respectively. As for the GSM communication system, the system was characterized based on accuracy of the information send via GSM text message and its delay. The developed system offers economical and practical monitoring system to be adopted for transmission cable temperature monitoring in remote area.

Ampacity derating factors for submarine transmission cables in J-tubes

With the development of deep-sea wind power, the temperature hotspots of submarine cables in J-tubes are getting increasing attention. Currently, the relevant standards do not provide a thermal rating method for such cable sections, and the only studies are difficult to apply in practice. This study derived an analytical solution for calculating the derating in ampacity of submarine cables within J-tubes. The proposed approach is efficient and readily integrated with IEC-related standards. Initially, an indoor experiment was conducted to validate the correctness of the analytical model. Subsequently, a numerical example utilizing an actual HVDC submarine cable is presented, demonstrating increased cable conductor temperature within the J-tube and a corresponding reduction in ampacity. A derating factor is employed to quantify the extent of ampacity reduction, which is a function of the J-tube length, outer diameter, ambient temperature, wind speed, and solar radiation intensity. It turns out that once the J-tube air section's length exceeds approximately 60 times the cable outer diameter, the transmission circuit ampacity can be based on the value installed in the infinite J-tube. Furthermore, factors resulting in substantial cable ampacity reduction, such as high solar radiation intensity, may yield a derating factor approaching 0.6.

Wireless optically pumped magnetometer MEG

The current magnetoencephalography (MEG) systems, which rely on cables for control and signal transmission, do not fully realize the potential of wearable optically pumped magnetometers (OPM). This study presents a significant advancement in wireless OPM-MEG by reducing magnetization in the electronics and developing a tailored wireless communication protocol. Our protocol effectively eliminates electromagnetic interference, particularly in the critical frequency bands of MEG signals, and accurately synchronizes the acquisition and stimulation channels with the host computer's clock. We have successfully achieved single-channel wireless OPM-MEG measurement and demonstrated its reliability by replicating three well-established experiments: The alpha rhythm, auditory evoked field, and steady-state visual evoked field in the human brain. Our prototype wireless OPM-MEG system not only streamlines the measurement process but also represents a major step forward in the development of wearable OPM-MEG applications in both neuroscience and clinical research.

The implementation of a cost‐efficient damped AC testing methodology for transmission cables based on DC–AC conversion and distributed partial discharge detection

AbstractThis research introduces a novel damped alternating current (DAC) testing methodology, which integrates an enhanced DAC generator with a pulse‐based distributed partial discharge (PD) detection technique. The advanced DAC generator is designed without the need for high voltage (HV) solid‐state switches, thereby offering a cost‐effective solution for field‐testing voltage generation through a direct current–alternating current conversion approach. To meet the demand for high instantaneous power, a capacitor bank is employed as the power supply. Furthermore, the implementation of a distributed PD detection technique enhances sensitivity and eliminates limitations associated with cable length. To minimize the construction costs of the distributed PD‐detection system, a pulse synchronization technique has been employed. Efforts to reduce the system's weight were informed by simulations, resulting in the design and development of a prototype weighing 850 kg for a 64/110 kV power cable. The reduction in the number of HV solid‐state switches contributes to significant cost savings, amounting to tens of thousands of dollars, when compared to conventional DAC generators. Laboratory and field tests validated the effectiveness of the cost‐efficient DAC testing methodology.

Techno-Economic Assessment of Coaxial HTS HVAC Transmission Cables with Critical Current Grading between Phases Using the OSCaR Tool

In recent years, the scientific and industrial interest regarding alternative technologies for transmission cables has increased. These conductors should efficiently transmit significant amounts of power between grid nodes, which are expected to be particularly congested due to the projected global increase in electricity production. Superconducting cables are considered a promising solution in this context, offering the potential to transmit large amounts of energy with minimal losses and compact dimensions, thereby potentially benefiting the environment. To evaluate the feasibility of integrating superconducting cables into existing grids, techno-economic approaches should be adopted. Such techniques enable the conceptual design of a specific cable structure, allowing users to explore a wide range of operating parameters to derive optimal designs. This paper reports a comprehensive techno-economic analysis of High Voltage Alternating Current (HVAC) cables realized with High-Temperature Superconducting (HTS) tapes, with the aim to transmit extremely high-power level. The optimal coaxial design is selected using Optimization Tool for Superconducting Cable Research (OSCaR) by implementing a graded approach to the critical current of the HTS tapes used for the different phases. This optimization aims to achieve the most effective balance between the cost of the coated conductors and their electrical properties. The whole set of model equations, the user-defined parameters, and the applied constraints are detailed. The OSCaR tool is then applied to assess the impact on the optimized design of the cable system and the corresponding cost indexes of several crucial parameters, such as the maximum transmitted power, the voltage level, and the line length.

Optimal Design of High-Power Density Medium-Voltage Direct Current Bipolar Power Cables for Lunar Power Transmission

Power systems on the lunar surface require power lines of varying lengths and capacities to connect generation, storage, and load facilities. These lines must be designed to perform efficiently in the harsh lunar environment, considering factors such as weight, volume, safety, cost-effectiveness, and reliability. Traditional power transmission methods face challenges in this environment due to temperature fluctuations, micrometeoroid impacts, and ionizing radiation. Underground deployment, although generally safer, faces challenges due to low soil thermal conductivity. At a depth of 30 cm, the lunar temperature of −23.15 °C can be advantageous for managing waste heat. This study presents a novel approach, developed using COMSOL Multiphysics, for designing bipolar MVDC cables for lunar subsurface power transmission. Kapton® MT+ is chosen as the insulating material for its exceptional properties, including high thermal conductivity and superior dielectric strength. The cables are designed for voltages of ±10 kV and ±5 kV and capacities of 200 kW (low power), 1 MW (medium power), and 2 MW (high power). Our findings indicate that aluminum conductors offer superior performance compared to copper at medium and high power levels. Additionally, elevated voltage levels (±10 kV) enhance cable design and power transfer efficiency. These specially designed cables are well-suited for efficient operation in the challenging lunar environment.

Optimal reactive power dispatch with renewable energy sources using hybrid whale and sine cosine optimization algorithm

The optimization of reactive power dispatch entails the complex challenge of controlling and managing the flow of reactive power in power networks to maintain desired voltage levels across many buses. Nowadays, there is a rising preference for employing renewable energy sources rather than traditional thermal generators. This change presents both challenges and possibilities for power system operators and managers. This paper addresses the Optimal Reactive Power Dispatch (ORPD) problem by presenting a novel approach that incorporates solar and wind power plants into existing power networks using the Hybrid Whale and Sine Cosine Optimisation Algorithm (HWSCOA). Solar and wind power plants are established at bus 5 and bus 8 respectively to replace traditional thermal generators in a specific case study using the IEEE 30-bus system. To handle uncertainties associated with load demand changes and the intermittent nature of renewable energy generation, the study employs probability density functions and a variety of scenarios. The primary goal is to minimize power losses in transmission cables while also lowering voltage changes throughout the network. To address uncertainty in load demands and renewable energy output, a scenario-based methodology is used, generating 30 different scenarios to cover all conceivable outcomes. By presenting the ORPD challenge as an optimization problem, the study hopes to achieve considerable reductions in power losses and voltage variations from nominal levels. The findings of this study reveal encouraging results, including significant reductions in power losses and optimized voltage stability even under shifting conditions.

Sustainable Maintenance of Conductors in Transmission/Distribution Networks Using Complex Magnetic Field Analysis

This study presents issues related to electromagnetic pollution and the level of magnetic field radiation occurring around conductors used for electricity transmission and distribution. The fact that modeling and simulation are the most efficient methods of optimization, considering the cost–benefit ratio, was the premise of this work. This paper proposes the performance of a complex analysis, carried out in a comparative manner, which includes physical tests and simulations in the existing field around transmission and distribution cables used in transformer substations. In the first stage, the level of the magnetic field existing near the conductor carried by an electric current was tested (measured), and a virtual model was then designed to simulate the field in conditions similar to those of the test. The results obtained from the simulation were analyzed in comparison with those obtained by testing. The maximum permissible limits of exposure to an electromagnetic field, which are regulated by Government Decision HG 520/2016 of 20 July 2016 and Directive 2013/35/EU of the European Parliament and of the Council of 26 June 2013, were used as the reference to formulate conclusions for both situations considered. These comparisons were intended to determine the level of exposure to electromagnetic fields existing in places where electricity transmission/distribution conductors are located. Energy sustainability exists due to the versatile properties of the conductors, with the energy transmission and distribution network being functional regardless of the source of energy production.

Research on the Protection Scheme of a High-Speed Railway Crossing 1000 KV Ultra-High Voltage Transmission Line

The high-speed railway project and the ultra-high-voltage transmission project represent two crucial components of China’s “new infrastructure”. As the construction of these two projects progresses rapidly, it is inevitable that instances of intersections will occur. Extreme conditions may cause damage to ultra-high voltage transmission cables. When a high-speed train passes by an ultra-high voltage transmission line, it poses a serious safety hazard. To address this issue, engineering examples were utilized to examine the protection structure scheme, protection distance, protection load, and construction procedures when a high-speed railway intersects a 1000 KV ultra-high voltage transmission line. A shed structure form and construction method for the electric power protection were proposed to ensure the safe operation of the high-speed railway while also achieving the safe and rapid construction of the high-speed railway protection structure in the safety zone of the approaching 1000 kV ultra-high voltage transmission line. The results indicated that the protection of high-speed railway crossings and 1000 kV ultra-high voltage transmission lines primarily focuses on line-break protection. The concrete shed structure with a straight wall and a flat roof was designed to meet the requirements of high-speed railway crossings. The line-break protection method enables the construction of an automatic warning protection corridor and a complete movable trolley quickly and safely within the safety zone near the transmission line. The implementation effect is, therefore, positive. It can be used as a reference point for other projects of a similar nature.

Two-terminal traveling wave fault location approach based on frequency dependent electrical parameters of HVAC cable transmission lines

With the expansion of high-voltage alternating current transmission networks, the widely used two-terminal traveling wave method faces several challenges in cable fault location. On one hand, the frequency dependent characteristics of longer cable transmission lines can significantly impact the accuracy of traveling wave propagation velocity. On the other hand, the processing of traveling wave signals obtained synchronously is also a crucial factor that requires attention. To enhance the performance of cable fault location, the principles of two-terminal traveling wave method need to be updated. Firstly, the cable model derived from the theory of wave propagation in multi-conductor systems is presented, which reflects the frequency dependent characteristics of the electrical parameters. Whereupon, an innovative cable traveling wave fault location scheme primarily composed of arrival time identification and instantaneous frequency calculation is proposed. Eventually, based on electromagnetic transient simulation software PSCAD/EMTDC, the robustness of the innovative cable fault location method against fault type, fault location, fault resistance, fault initial angle and earth resistivity issues is demonstrated.

A Study on Fault Localization Method of Three-Terminal Multi-Section Overhead Line–Cable Hybrid Line Using MEEMD Combined with Teager Energy Operator Algorithm

An improved fault localization method combining total aggregate empirical modal decomposition (MEEMD) and Teager energy operator (TEO) is proposed to address the fault localization issue of three-terminal multi-segment overhead line–cable hybrid transmission lines. This method solves the fault localization problem caused by wave impedance discontinuity in hybrid lines. First, the MEEMD algorithm, which improves modal aliasing, and the Teager energy operator, which reflects transient energy changes, are combined for the accurate detection of faulty traveling wave heads. The fault line section determination condition within the fault branch is used to determine the overhead line section or cable section where the fault is located after determining the faulty branch line. This condition is based on the time difference between the initial traveling wave of the fault arriving at each end measurement point and the T-node. Ultimately, the fault distance is determined using the double-ended traveling wave technique. By combining PSCAD and MATLAB for simulation verification, the accuracy of the ranging method is compared and analyzed, and the results show that the method is able to ensure the accuracy of ranging at different fault locations and transition resistances. Additionally, the localization error is basically kept within 30 m, which significantly improves the accuracy of fault localization.

P‐76: The Influence of Bending FFC Transmission Line on High‐Speed Signal Channels

Generally, display devices interconnect FFC transmission lines with circuits to form a transmission line network system to achieve data communication between Tcon and Driver. Due to the limitations of the external shape and internal space structure of the display device, the FFC transmission cable presents a curved shape from 0 to 180 degrees during the wiring process. Under the action of spatial electromagnetic fields, the display device will involve the field‐circuit hybrid problem of electromagnetic coupling of the FFC transmission line's bent line and circuit conduction interference, which will cause severe electromagnetic interference(EMI), resulting in deterioration of the high‐speed channel signal at the receiving end and even inability to correctly restore and decode the signal, thus causing signal distortion, which in turn leads to display image distortion or pixel loss.

The role of inter-island transmission in full decarbonisation scenarios for Indonesia’s power sector

Indonesia has large renewable energy resources that are not always located in regions where they are needed. Sub-sea power transmission cables, or island links, could connect Indonesia’s high-demand islands, like Java, to large-resource islands. However, the role of island links in Indonesia’s energy transition has been explored in a limited fashion. Considering Indonesia’s current fossil fuel dependency, this is a critical knowledge gap. Here we assess the role of island links in Indonesia’s full power sector decarbonisation via energy system optimisation modelling and an extensive scenario and sensitivity analysis. We find that island links could be crucial by providing access to the most cost-effective resources across the country, like onshore photovoltaics (PV) and hydropower from Kalimantan and geothermal from Sumatera. In 2050, 43 GW of inter-island transmission lines enable 410 GWp of PV providing half of total generation, coupled with 100 GW of storage, at levelised system costs of 60 US$(2021)/MWh. Without island links, Java could still be supplied locally, but at 15% higher costs due to larger offshore floating PV and storage capacity requirements. Regardless of the degree of interconnection, biomass, large hydro, and geothermal remain important dispatchable generators with at least 62 GW and 23% of total generation throughout all tested scenarios. Full decarbonisation by 2040 mitigates an additional 464 MtCO2e compared to decarbonisation by 2050, but poses more challenges for renewables upscaling and fossil capacity retirement.

The Short-Term Price Elasticity, Temperature Elasticity, and Wind Speed Elasticity of Electricity: A Case Study from Norway

Energy production using hydropower has a 150-year history in Norway. High mountains, lots of rain, and a well-developed technology laid the foundation for low and stable electricity prices. The Norwegian electricity market is unique and different from any other country. Nearly all electricity produced (98.3 percent) comes from renewable energy sources and 75 percent of the energy used for heating is electricity. From autumn 2020, major changes have been observed in the electricity market in Norway. In 2021, Norway opened two transmission cables, one to Germany and one to England. Both cables have a capacity of 1400 MW. The average price per MWh was NOK 263 in southern Norway in the period 2013–2020, which more than quadrupled to NOK 1192 per MWh in the period 2021–2023. We have investigated how the market reacted to the large price increase. We found that price elasticity is low even when the price is very high. It is the temperature that controls the consumption. When it is cold—below zero degrees Celcius—the temperature elasticity is close to zero; the temperature elasticity is not constant. When the temperature is above zero, the temperature elasticity is about −0.7. Price variations or changes in wind speed only lead to minor adjustments in electricity consumption. It is the variations in temperature that result in the observable fluctuations in electricity consumption. Since Norway exports electricity to Sweden, Denmark, Finland, Germany, the Netherlands, and England, knowledge of the Norwegian electricity market is relevant for many market participants. The Norwegian electricity market differs from those in other countries. Therefore, there is a risk that conclusions drawn about the Norwegian electricity market based on research conducted in other countries may be incorrect or inaccurate. Our contribution with this case study is to deepen the knowledge of how the electricity market in Norway operates.

Performance Investigation on PMSG based Fractional Frequency Transmission Systems via XLPE cables for Offshore Wind Power

Presently, the research on Fractional Frequency Transmission System (FFTS) is fastened for the megawatt Offshore Wind Farms (OWF). FFTS has an ability to overcome the problem of charging current presented in the HVAC transmission and will effectively serve as an alternative to the traditional transmission systems. The basic structures and characteristics of a typical PMSG-based FFTS via XLPE cable for offshore wind power system is proposed and described first. Then the technical performance of power transmission through XLPE cable is evaluated by comparing the different cables such as flat and trefoil formation. Simulation results showcase notable enhancements in power transfer capacity, decreased power losses, and improved performance of control schemes. The feasibility studies describe the performance of FFTS (16.67 Hz) via trefoil cable is superior than FFTS flat formation cable transmission.

A Framework for Modeling, Optimization, and Musculoskeletal Simulation of an Elbow–Wrist Exosuit

The light weight and compliance of exosuits are valuable benefits not present rigid exoskeleton devices, yet these intriguing features make it challenging to properly model and simulate their interaction with the musculoskeletal system. Tendon-driven exosuits adopt an electrical motor combined with pulleys and cable transmission in the actuation stage. An important aspect of the design of these systems for the load transfer efficacy and comfort of the user is the anchor point positioning. In this paper, we propose a framework, whose first purpose is as a design methodology for the synthesis of an exosuit device, achieved by optimizing the anchor point location. The optimization procedure finds the best 3D position of the anchor points based on the interaction forces between the exosuit and the upper arm. The computation of the forces is based on the combination of a mathematical model of a wrist–elbow exosuit and a dynamic model of the upper arm. Its second purpose is the simulation of the kinematic and physiological effects of the interaction between the arm, the exosuit, and the complex upper limb musculoskeletal system. It offers insights into muscular and exoskeleton loading during operation. The presented experiments involve the development and validation of personalized musculoskeletal models, with kinematic, anthropometric, and electromyographic data measured in a load-lifting task. Simulation of the exosuit operation—coupled with the musculoskeletal model—showed the efficacy of the suit in assisting the wrist and elbow muscles and provided interesting highlights about the impact of the assistance on shoulder muscles. Finally, we provide a possible design of an elbow and wrist exosuit based on the optimized results.

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.

A Literature Survey on Underground Cable Fault Detection using IoT

The rise in use of Underground Cables for power Transmission is recent times due to its less maintenance and lower susceptibility to damage by weather, means that detection of any other faults that occur in them must be swift and efficient to ensure lower down-Time in transmission and supply. The survey goes through various fault detection methods that have been proposed, to find potential pros and cons and attempts at bettering them. While using various AI models in detection can be highly accurate to the cause, it still has some error margins to it. On the other hand using IoT (Microcomputers and sensors) make up for near perfect detection increasing the efficiency of the system. This requires a wide range of understanding on the topics of electricity and the working of these lines which is the goal of this paper

Overview of DC technology - Energy conversion

DC transmission and distribution systems have several advantages compared to classical AC system. This paper presents a review of DC technology, doing a special mention in HVDC. It addresses some issues like HVDC converter types, DC DC converter topologies, DC transmission and distribution topologies, transmission cables and DC circuit breakers with the main manufacturers and commercial devices.

Direct Air Cooling of Pipe-Type Transmission Cable for Ampacity Enhancement: Simulations and Experiments

Amid the growing demand for energy supply in modern cities, the enhancement of transmission capacity is receiving considerable attention. In this study, we propose a novel method of direct forced cooling in pipe-type transmission lines via an external air supply for reducing the cable temperature and enhancing the ampacity. We conducted numerical simulations using computationally efficient two-dimensional models and a reduced-length three-dimensional model for assessing the cooling efficiency, the distance required for temperature convergence, and the fan/pump capacity required for forced air cooling. We found a 26% increase in ampacity in the case of 5 m/s inlet air velocity into the pipe conduit. We also built and tested the experimental setup equipped with a 300 m length model transmission cable. Results of the forced air cooling experiments show good agreement with numerical simulations. To the best of our knowledge, this study demonstrates the first analysis and validation of direct cooling in pipe-type cables, presenting a promising path for efficient power management in modern metropolitan areas.