Transmission Lines For Applications Research Articles

Empowering Photovoltaic Panel Anti-Icing: Superhydrophobic Organic Composite Coating with In Situ Photothermal and Transparency.

Solar energy is widely used in photovoltaic power generation as a kind of clean energy. However, the liquid film, frosting, and icing on the photovoltaic module seriously limit the efficiency of photovoltaic power generation. We developed a composite coating (Y6-NanoSH) by combining an in situ photothermal and transparent Y6 organic film with a nanosuperhydrophobic material. The Y6-NanoSH coated glass exhibited excellent optical clarity both indoors and outdoors, indicating that the coating holds great promise in anti-icing applications for photovoltaic panels. The Y6-NanoSH coating absorbs very little visible light but instead absorbs in the near-infrared region, thereby emitting heat. When exposed to sunlight, the Y6-NanoSH coated photovoltaic panel raises its surface temperature, inhibiting the growth and accumulation of ice and frost on its surface. This is achieved through a combination of photothermal emission and superhydrophobic repellency, which promotes the evaporation and rolling away of water droplets. This validates our success in developing a photothermal, transparent, and superhydrophobic coating with excellent anti-icing capabilities, suitable for use on photovoltaic panels, as well as potential applications in car windscreens, transmission lines, curtain walls, and weather radomes.

Compact, robust, and regulated-output hybrid generators for magnetic energy harvesting and self-powered sensing applications in power transmission lines

A hybrid magnetic energy harvester is demonstrated for self-powered sensors in transmission lines, showcasing unprecedented power density, compact size, lightweight, waterproofing, resilience to current fluctuations, and environmental robustness.

Multi‐Mode Vibrational Triboelectric Nanogenerator for Broadband Energy Harvesting and Utilization in Smart Transmission Lines

AbstractThe advantages of the triboelectric nanogenerator (TENG) in environmental energy harvesting and utilization determine that they have great development potential in the digital application of power grids. This work focuses on the harvesting and utilization of vibration energy from transmission lines, specifically in the context of breeze vibrations and sub‐span oscillations. To this end, this work proposes a novel multi‐mode vibrational triboelectric nanogenerator (MV‐TENG) and three smart transmission line application strategies based on the MV‐TENG. The MV‐TENG design consists of an S‐beam to broaden the frequency response range by reducing high‐order modal frequencies, and a pair of allegro electrodes to efficiently harvest horizontal and vertical vibration energy. The MV‐TENG demonstrates the capability to harvest vibration energy within a range of 1–3.5 Hz horizontally and 4 Hz, 9–60 Hz vertically, covering the occurrence range of breeze vibrations and sub‐span oscillations of transmission line effectively. Three application strategies include self‐powered tower obstacle alerting, temperature and humidity online monitoring, and high‐temperature wireless warning of transmission lines based on MV‐TENG. In summary, this work presents a comprehensive implementation scheme for digitally integrating TENGs into smart transmission lines, thereby facilitating the engineering development of TENG technology in grid systems.

Review of Technological Advances in High Temperature Overhead Line Composite Conductors

ACSR (Aluminium Conductor Steel Reinforced) conductors consisting of pure aluminum wires helically stranded around a core of high strength galvanized steel core wires are widely used in overhead transmission line applications. While the steel wires provides the required strength, the outer aluminium serves as electricity conducting member. The thermal rating or ampacity of conductors is the maximum current that a circuit can carry within the temperature limits as dictated by the allowable conductor sag or by the annealing onset temperature of the conductor, whichever is lower. On a continuous basis, ACSR may be operated at temperatures up to 100°C without any significant change in the conductor’s physical properties. Above 100°C, aluminum wires loses tensile strength over time and becomes "fully annealed" giving rise to increased thermal expansion of the conductor; this causes excessive sagging reducing the clearance between the ground and the energized conductors.
 While, the electric utilities are posed with increased challenges of production of additional capacities and building new transmission circuits to meet the ever growing demand and the high cost and environmental restrictions of constructing new lines, methods are being explored to increase their capacity with minimum changes in the existing towers. Replacement of the existing conductor with a advanced high temperature composite (HTC) conductors operating upto temperatures of 200°C with reduced sagging characteristics have been attempted and an increase in capacity of 30-80%, can be achieved through application of these composite conductors.
 The advanced HTC conductors with varied combinations of core material and outer conducting wires are being tried so as to achieve wide ranging properties. In general, HTC conductors features the combinations of either soft aluminum wires with ultra high strength steel or temperature resistant aluminium with or fiber reinforced metal/polymer matrix composites as the core. Both the alumina fiber reinforced temperature resistant aluminium metal matrix composite and the carbon fiber reinforced high temperature polymer resin composite wires as the core material appears to have favorable applications. The comparative performance of the HTC depends on the degree to which both outer aluminum strand and reinforcing core’s physical properties are stable at high temperature and on the elastic, plastic, and thermal elongation of the combined HTC.
 The summary of various developments realized in the area of composite conductors and their relative merits and demerits have been discussed in detail.

재질에 따른 애자의 절연내력특성 분석에 관한 연구

In general, insulator is a type of support used to fix and insulate an electric wire to a pylon or electric pole and is made of porcelain, glass, or silicone polymer in a power transmission line or a railway line. In transmission line applications, insulators are exposed to severe electrical and environmental conditions as well as insulation. Insulators are manufactured using various materials, and dielectric strength performance is different depending on the type of material. In this research, the dielectric strength characteristics of insulators according to insulation materials are analyzed by conducting electrical breakdown experiments and finite element method (FEM) analysis. Finally, the degradation characteristics of three types of insulators such as glass, porcelain, and polymer insulators are compared and analyzed through dry flashover and wet flashover experiments. In addition, electric field distribution analysis considering the type of insulator is analyzed by FEM simulation.

A dual-band frequency scanning antenna based on spoof SPPs transmission line

In this paper, a dual-band frequency scanning antenna based on spoof SPPs transmission line was proposed. The effect of each parameter in the rectangular holes of spoof SPPs on the dispersion characteristics and the frequency band of the spoof SPPs transmission line application was analyzed. The results show that the depths of rectangular hole have a large effect on the cut-off frequency, and etching two rectangular holes of different depths in a metal strip can generate standing waves in the transmission line. Based on this structure, a dual-band frequency scanning antenna was designed by combining magnetic coupling with the principle of leakage radiation. Loading two sets of circular patches of different sizes on both sides of the spoof SPPs transmission line achieved a dual-band frequency sweep of 90° – 196 ° in the 4–9 GHz and 126°–192° in the 16–32 GHz, with sweep angles of 106° and 66°. The antenna achieved a gain of 10–12 dBi in the operating band with an average radiation efficiency about 90%. The antenna was subjected to processing and testing, and the experimental results verified the good frequency scanning characteristics. The antenna proposed has a great potential for use in planar integrated communication systems and fifth-generation wireless communication system.

Electrical Properties of Iodine-Doped Cu/f-CNT Coated Aluminum Wires by Electrophoresis with Copper Sulfate Solution

This work investigated the effects of iodine on copper/functionalized carbon nanotubes (Cu/f-CNT) that were used in the coating of 1350 Aluminum Alloy wires, using the process of electrophoretic exposure with a solution of copper sulfate and iodine, under an electrical current of 1.2 A and a voltage of 10 V. The Al@Cu/f-CNT was characterized by Scanning Electron Microscopy in Secondary Electron mode, X-ray Diffraction and Raman spectroscopy, in addition to electrical measurements, at room temperature and under heating, via kelvin bridge. The results showed an increase of approximately 18% in the electrical conductivity of the IACS compared to the standard aluminum conductor, due to the iodine doping of the outer walls of the f-CNT, causing an expansion between the layers, and reflecting the increase in the conduction channels. This method of electrodeposition of Cu/f-CNT on the surface of metallic wires shows promise for the production of nanostructured cables with high ampacity, lightness and high performance, for application in power transmission lines.

Flexural Creep Behaviour of Pultruded GFRP Composites Cross-Arm: A Comparative Study on the Effects of Stacking Sequence.

Pultruded glass fibre reinforced polymer (pGFRP) composites provide outstanding properties for composite polymer cross arms in power transmission line applications. This study has investigated the effects of various stacking sequences of fibres directions of pGFRP on flexural strength and creep behaviour. The use of static four-point bending flexural tests revealed that Stacking Sequence 2 (±45/0/90/0/90/0) had a significant flexural strength of 399.9 MPa while Stacking Sequence 1 (±45/90/0/±45) had a flexural strength of 242.5 MPa. Furthermore, the four-point bending creep experiments were performed at three distinct stress levels, notably 12%, 24%, and 37% of the ultimate flexural strength, to characterise the creep behaviour of distinct stacking sequences. Moreover, Findley’s power law equation for bending creep behaviour has revealed that the time-dependent reduction factor of Stacking Sequence 1 and Stacking Sequence 2 estimates a drop in flexural modulus of 23% and 10% respectively.

Anti-icing ceramics surface induced by femtosecond laser

Femtosecond (fs) laser, as an efficient and precise microfabrication tool, has been widely used in material processing. Superhydrophobic surfaces have many applications in anti-icing, self-cleaning and frost resistance. In this paper, nested micro/nanostructures were induced by fs laser on the surface of alumina ceramics. After modification by polydimethylsiloxane (PDMS), the ceramics surface induced by fs laser changes from superhydrophilicity to superhydrophobicity. The anti-icing and frost resistance of functional ceramics surface were studied. Scanning electron microscope (SEM) images show that the cross-scanning laser processing mode can induce the nested micro/nanostructures on ceramics surface, resulting in excellent superhydrophobic surface with water contact angle (WCA) up to176.39° and water rolling angle (WRA) as low as 1°. The experimental results show that the dynamic process of droplet icing on superhydrophobic surface includes three typical states, and the freezing delay time of droplet is mainly caused by the change from the liquid phase to the ice shell. The freezing delay time of the superhydrophobic surface is 189 s laser than that of the intrinsic ceramics surface. In addition, the distance between the adjacent condensation droplets on superhydrophobic ceramics is larger than that on intrinsic surface, which can effectively prevent the diffusion of frost. The superhydrophobic ceramic with frost resistance and anti-icing has a wide application in power transmission lines, aircraft, wind turbine blades, air conditioning pipe and chemical production.

Compensation circuit design for tuned half-wavelength transmission lines based on Bessel filter

Compensation circuit, which can increase electrical length, is the most feasible solution for flexible applications of half-wavelength transmission lines (HWTL). In previous studies, it is always assumed that the compensation circuit is structured by passive components with identical parameters to represent the distribution parameter of transmission lines. However, the structure of the traditional compensation circuit is actually equivalent to that of the constant k filter, which concludes that the compensation circuit is fundamentally a low-pass filter. In consideration of basic requirements for tuned HWTL, the Bessel filter, which has smooth group delays without waveform distortion, is selected for the calculation of compensation circuit parameters in this paper. Lastly, the Bessel-based compensation circuit is compared to natural HWTL and tuned HWTL with Butterworth filter-based and traditional compensation circuits. Comprehensive cases simulated by PSCAD are undertaken, which validate that the voltage distribution of Bessel-based compensation circuits is quite similar to that of traditional compensation circuits. Moreover, electromagnetic transients can induce significant high-frequency oscillations in tuned HWTL with traditional compensation circuits, but high-frequency oscillation is significantly reduced by Bessel-based compensation circuits. Therefore, the Bessel-based compensation circuit is verified to be a better solution for tuned HWTL.

A Decommissioned Wind Blade as a Second-Life Construction Material for a Transmission Pole

This paper demonstrates the concept of adaptive repurposing of a portion of a decommissioned Clipper C96 wind turbine blade as a pole in a power transmission line application. The current research program is aimed at creating a path towards sustainable repurposing of wind turbine blades after they are removed from service. The present work includes modelling and analysis of expected load cases as prescribed in ASCE 74 and NESC using simplified boundary conditions for tangent pole applications. Load cases involving extreme wind, concurrent ice and wind, extreme ice, differential ice, broken conductor, and broken shield have been analyzed and governing load cases for bending, shear, and torsion have been examined. Relative stiffnesses of different parts forming the wind blade’s cross section (i.e., shell, web, and spar cap) are determined. The corresponding stresses associated with each part under the governing loads are compared to allowable strength values which are determined from composite laminate theory and modelling of the known laminate structure of the E-Glass FRP material. Stresses and deflections obtained are compared with governing reliability-based design criteria and code requirements. The results of the structural analysis indicate that the wind blade can resist the expected loads with reasonable safety factors and that the expected deflections are within permissible limits. Recommendations are provided for detailing and modification of the wind blade for a power pole application in which crossarm and davit connections are highlighted, and foundation details are emphasized.

Fault impedance analysis and non-conventional distance protection settings for half-wavelength transmission line applications

This paper presents an analysis of fault phase impedance and its dynamic response for half-wavelength (HWL) transmission lines. One important issue of this technology is fault protection as distance protection elements are based on impedance for conventional AC lines. HWL line has very long length, preventing the direct application of classical impedance method because the capacitance effect produces different impedance behavior. This paper analyzes and characterizes the phase impedance response, and proposes alternative distance protection settings focusing on solving the problem of line-to-line fault detection. It is proven that the algorithm covers 84% of the line length. However, faults in the central region have a high resistance characteristic and cannot be detected with the proposed method. The paper takes into account the influence of line transpositions that further affects the protection performance near central region. Transient analysis and software in the loop tests were performed with PSCAD/EMTDC.

Thermally stable Al conductor prepared from Al powder with a low oxygen content

Abstract The high thermal stability of pure Al conductors is an urgent requirement for their applications in power transmission lines. Powder metallurgy (PM) Al conductor was produced in this work from Al powder with a low oxygen content (~0.1 wt%), followed by cold isostatic pressing, sintering, hot extrusion, and cold drawing. The microstructure evolution, mechanical properties and electrical conductivity of hot-extruded rods and cold-drawn wires before and after annealing at 300 °C and 500 °C were investigated. The γ-Al2O3 nanoparticles located primarily at high angle grain boundaries promote the stabilization of Al grains, resulting in enhanced annealing strength (89 MPa), almost twice higher than commercial pure Al (45 MPa). Fine grains and texture play a significant role in the overall strength (160 MPa) of PM Al conductors. One interesting finding is that the electrical conductivity of cold-drawn wires (60.2% IACS) is higher than the hot-extruded rods (58.7% IACS) due to the beneficial evolution of initial Al2O3 film and grain boundaries. The compatibility of documented strength-structure Hall-Petch relation was discussed. Optimal properties (172 MPa ultimate tensile strength and 60.2% IACS electrical conductivity) were obtained through cold drawing. These results push forward the potential application of PM Al in heat resistant conductors.

Resource utilization of composite insulator silicone rubber

Composite insulators provide highly effective insulation support, and their application in power transmission lines has seen rapid growth in recent years. However, every year, a large quantity of composite insulators are scrapped on reaching the end of their service life. Due to the exceptional chemical inertness of the silicone rubber in the insulators, they have poor self-degradation characteristics, and end up filling landfills and occupying a lot of space, which inadvertently endangers the ecological environment. So far, there has not been any effective means to recycle composite insulators. This paper analyzes the material composition and characteristics of the silicone rubber in the core and housing of composite insulators, and proposes a resource utilization approach for the application of the pulverized silicone rubber powder from the insulators in the following three applications: use in producing silicone rubber asphalt at a blending ratio of 15%–18%—the corresponding market demand is large enough to meet the disposal needs of scrapped composite insulators; use in modification of waste rubber powder and blending with ethylene propylene diene monomer rubber (EPDM) at a blending ratio of 10%—as the annual production capacity of EPDM is more than 850,000 tons in China, thousands of tons of waste insulators can be thus disposed; and use as an aggregate for non-slip coatings, which accounts for more than 40% of the coatings material. Thus, there is tremendous scope for recycling waste insulator.

Application Status of Planar Artificial Transmission Line in Antenna Design

Abstract Using the dispersion characteristics and media characteristics of planar artificial transmission lines, we not only can realize the miniaturization, dual/multi-frequency, broadband of components in antenna-feeder systems, but also can realize new functions that conventional transmission lines have not in antenna-feeder systems. In this paper, the application of planar artificial transmission line in the design of multi-functional antenna, which provides a reference for the future design, is analyzed.

Physics and topological properties of periodic and aperiodic transmission line networks

Transmission line is a common kind of one-dimensional waveguide. In addition to being widely used in engineering, the transmission lines can be used in proof-of-principle experiments in basic scientific research. For example, the wave equations governing the transmission line and quantum wire are equivalent, so transmission lines are widely used in the research of quantum graphs. The transmission line network equations are similar to the equations of zero-energy tight binding model, so the transmission line network can also be used to study some physical properties predicted by the theories based on tight binding model, and examples include Anderson localization, band dispersions, topological properties, etc. According to the transmission line network equations, we review some applications of transmission lines in the research fields mentioned above. We will discuss Anderson localization in one-, two-, and three-dimensional networks, the band structures of periodic and quasiperiodic networks, and the angular moment-dependent topological transport in transmission line network. We introduce the methods and results in detail to show the potential of transmission lines in basic scientific research.

Harmonics and THD in Five Phase Inverters

Now-a-days most of the appliances and machine works on AC power. If AC power is unavailable for a short period of time, then during that period we need to supply AC power by converting the stored DC power. This can be possible using an Inverter. Inverters can be of multi-phase i.e. 3phase, 5phase, 6phase and so on. Since inverters have wide application in industries and HVDC transmission lines, the improvement in the output voltage and the reduction in harmonics are of utmost importance. In this paper a detailed analysis of harmonics and THD in a five phase inverter with different conduction angle along with the derived mathematical equations has been presented. A comparative study between three phase and five phase inverters at different conduction angle has been presented.

Radio Frequency Transmission: Improving Radio Frequency Transmission Properties of Graphene via Carrier Concentration Control toward High Frequency Transmission Line Applications (Adv. Funct. Mater. 18/2019)

Radio Frequency Transmission: Improving Radio Frequency Transmission Properties of Graphene via Carrier Concentration Control toward High Frequency Transmission Line Applications (Adv. Funct. Mater. 18/2019)

Development of a Self-Powered Temperature Monitoring Wireless Node for Transmission Lines for Smart Grid Application

Increasing the safe operating temperature limits of the transmission line, by a small percentage above the present safe operating temperature limit can help in transmission of more power over existing lines and it would also help in avoiding huge investment and loss of time due to regulatory processes for establishment of new lines. Since the operating temperature is a critical parameter for transmission of the power, low cost sensors on high tension lines would enable data acquisition on real time basis for faster decision making. This is an alternative power source to the battery or solar panels. The results of laboratory experiments and data on simulation for the developed self-powered temperature, sag and tension monitoring system are presented and discussed in this paper. A comparison of two different methods of computation of temperature based on frequency and amplitude of output signal and cost benefit of the different methods of powering the wireless sensor nodes for transmission line application are also discussed.

Improving Radio Frequency Transmission Properties of Graphene via Carrier Concentration Control toward High Frequency Transmission Line Applications

AbstractGraphene has been gradually studied as a high‐frequency transmission line material owing to high carrier mobility with frequency independence up to a few THz. However, the graphene‐based transmission lines have poor conductivity due to their low carrier concentration. Here, it is observed that the radio frequency (RF) transmission performance could be severely hampered by the defect‐induced scattering, even though the carrier concentration is increased. As a possible solution, the deposition of the amorphous carbon on the graphene is studied in the high‐frequency region up to 110 GHz. The DC resistance is reduced by as much as 60%, and the RF transmission property is also enhanced by 3 dB. Also, the amorphous carbon covered graphene shows stable performance under a harsh environment. These results prove that the carrier concentration control is an effective and a facile method to improve the transmission performance of graphene. It opens up the possibilities of using graphene as interconnects in the ultrahigh‐frequency region.