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Double-circuit
An overhead power line is a structure used in electric power transmission and distribution to transmit electrical energy across large distances. It consists of one or more uninsulated electrical cables (commonly multiples of three for three-phase power) suspended by towers or poles. Since most of the insulation is provided by the surrounding air, overhead power lines are generally the least costly method of power transmission for large quantities of electric energy. Construction Towers for support of the lines are made of wood either grown or laminated, steel or aluminum (either lattice structures or tubular poles), concrete, and occasionally reinforced plastics. The bare wire conductors on the line are generally made of aluminum (either plain or reinforced with steel or composite materials such as carbon and glass fiber), though some copper wires are used in medium-voltage distribution and low-voltage connections to customer premises. A major goal of overhead power line de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtransmission
Electric power transmission is the bulk movement of electrical energy from a generating site, such as a power plant, to an electrical substation. The interconnected lines that facilitate this movement form a ''transmission network''. This is distinct from the local wiring between high-voltage substations and customers, which is typically referred to as electric power distribution. The combined transmission and distribution network is part of electricity delivery, known as the electrical grid. Efficient long-distance transmission of electric power requires high voltages. This reduces the losses produced by strong currents. Transmission lines use either alternating current (HVAC) or direct current (HVDC). The voltage level is changed with transformers. The voltage is stepped up for transmission, then reduced for local distribution. A wide area synchronous grid, known as an "interconnection" in North America, directly connects generators delivering AC power with the same relativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Power Lines In Dnipro, Ukraine
Overhead may be: * Overhead (business), the ongoing operating costs of running a business * Engineering overhead, ancillary design features required by a component of a device ** Overhead (computing), ancillary computation required by an algorithm or program ** Protocol overhead, additional bandwidth used by a communications protocol ** Line code or encoding overhead, additional bandwidth required for physical line transmission * Overhead information, for telecommunication systems * File system overhead, storage or other consideration required by a file system that is not directly related to data. * Any physical object situated, or action occurring above: ** Overhead line, for power transmission ** Overhead cable, for signal transmission ** Overhead projector, a display system * Overhead cam, a mechanical device * Overhead join, in air traffic control See also * Overkill (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electricity Pylon
A transmission tower, also known as an electricity pylon or simply a pylon in British English and as a hydro tower in Canadian English, is a tall structure, usually a steel lattice tower, used to support an overhead power line. In electrical grids, they are generally used to carry high-voltage transmission lines that transport bulk electric power from generating stations to electrical substations; utility poles are used to support lower-voltage subtransmission and distribution lines that transport power from substations to electric customers. They come in a wide variety of shapes and sizes. Typical height ranges from , though the tallest are the towers of a span between the islands Jintang and Cezi in China's Zhejiang province. The longest span of any hydroelectric crossing ever built belongs to the powerline crossing of Ameralik fjord with a length of . In addition to steel, other materials may be used, including concrete and wood. There are four major categories of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balisor
Balisor is a system of illuminated beacons for high voltage power lines using a cold-cathode low-pressure neon lamp,David F. Rider '' Jane's airport equipment fifth edition'', Jane's Pub. Co., 1986 page 92 used as an aircraft warning light. Description High voltage power cables, particularly those close to airports, need to be visible day and night. During the day, brightly coloured balls positioned along the length of the cables are sufficient, but during the night, lighting is necessary. These beacons provide this lighting by glowing red, the standard colour used in aviation for warning beacons. The system is extremely simple, efficient and reliable and is considered the most economically viable solution. Its working principle is attractive, because it uses a phenomenon usually considered as a weakness. However a large disadvantage is that it does not work when the line is switched off. It cannot also be used on HVDC powerlines, but similar devices may be also used on mast r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Civil Aviation Organization
The International Civil Aviation Organization (ICAO, ) is a specialized agency of the United Nations that coordinates the principles and techniques of international air navigation, and fosters the planning and development of international scheduled air transport, air transport to ensure safe and orderly growth. ICAO headquarters are located in the ''Quartier international de Montréal, Quartier International'' of Montreal, Quebec, Canada. The ICAO Council adopts standards and recommended practices concerning air navigation, its infrastructure, flight inspection, prevention of unlawful interference, and facilitation of border-crossing procedures for international civil aviation. ICAO defines the protocols for Aviation accidents and incidents, air accident investigation that are followed by :Organizations investigating aviation accidents and incidents, transport safety authorities in countries signatory to the Chicago Convention on International Civil Aviation. The Air Navigat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead Wire Marker
Overhead wire markers are safety instruments applied to the overhead power lines marking transmission lines and ropeways along the flight path during the day. page 7-6 Markers are often installed on overhead lines near airfields, or at river crossings where there is a possibility of float-equipped aircraft using the river. Some markers contain or strobe lights to improve visibility at night or in fog. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Fiber
An optical fiber, or optical fibre in Commonwealth English, is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair. Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables. Fibers are used instead of metal wires because signals travel along them with less loss; in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer. Fibers are also used for illumination and imaging, and are often wrapped in bundles so they may be used to carry light into, or images out of confined spaces, as in the case of a fiberscope. Specially designed fibers are also used for a variety of other applications, some of them being fiber optic sensors and fiber lasers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Ground Wire
An optical ground wire (also known as an OPGW or, in the IEEE standard, an optical fiber composite overhead ground wire) is a type of cable that is used in overhead power lines. Such cable combines the functions of grounding and communications. An OPGW cable contains a tubular structure with one or more optical fibers in it, surrounded by layers of steel and aluminum wire. The OPGW cable is run between the tops of high-voltage electricity pylons. The conductive part of the cable serves to bond adjacent towers to earth ground, and shields the high-voltage conductors from lightning strikes. The optical fibers within the cable can be used for high-speed transmission of data, either for the electrical utility's own purposes of protection and control of the transmission line, for the utility's own voice and data communication, or may be leased or sold to third parties to serve as a high-speed fiber interconnection between cities.G. F. Moore, (ed) ''Electric Cables Handbook (3rd Edition) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strain Insulator
A strain insulator is an electrical insulator that is designed to work in mechanical tension (strain), to withstand the pull of a suspended electrical wire or cable. They are used in overhead electrical wiring, to support radio antennas and overhead power lines. A strain insulator may be inserted between two lengths of wire to isolate them electrically from each other while maintaining a mechanical connection, or where a wire attaches to a pole or tower, to transmit the pull of the wire to the support while insulating it electrically. Strain insulators were first used in telegraph systems in the mid 19th century. Description and use A typical strain insulator is a piece of glass, porcelain, or fiberglass that is shaped to accommodate two cables or a cable shoe and the supporting hardware on the support structure (hook eye, or eyelet on a steel pole/tower). The shape of the insulator maximizes the distance between the cables while also maximizing the load-bearing transfer capac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice Tower
A lattice tower or truss tower is a freestanding vertical framework tower. This construction is widely used in transmission towers carrying high voltage electric power lines, in radio masts and towers (a self-radiating tower or as a support for aerials) and in observation towers. Its advantage is good shear strength at a much lower weight than a tower of solid construction would have as well as lower wind resistance. In structural engineering the term ''lattice tower'' is used for a freestanding structure, while a ''lattice mast'' is a guyed mast supported by guy lines. Lattices of triangular (3-sided) cross-section are most common, particularly in North America. Square (4-sided) lattices are also widely used and are most common in Eurasia. Lattice towers are often designed as either a space frame or a hyperboloid structure. Before 1940, they were used as radio transmission towers especially for short and medium wave. Occasionally lattice towers consisting of wood were utilized. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undergrounding
In civil engineering, undergrounding is the replacement of overhead cables providing electrical power or telecommunications, with underground cables. It helps in wildfire prevention and in making the power lines less susceptible to outages during high winds, thunderstorms or heavy snow or ice storms. An added benefit of undergrounding is the aesthetic quality of the landscape without the powerlines. Undergrounding can increase the capital cost of electric power transmission and distribution but may decrease operating costs over the lifetime of the cables. History Early undergrounding had a basis in the detonation of mining explosives and in undersea telegraph cables. Electric cables were used in Russia to detonate mining explosives in 1812, and to carry telegraph signals across the English Channel in 1850. With the spread of early electrical power systems, undergrounding began to increase as well. Thomas Edison used underground DC “street pipes” in his early distributio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Visual Pollution
Visual pollution is the study of secondary impacts of manmade interventions or visible deterioration and negative aesthetic quality of the natural and human-made landscapes around people. It refers to the impacts pollution has in impairing the quality of the landscape and is formed from compounding sources of pollution to create it. Visual pollution disturbs the functionality and enjoyment of a given area, limiting the ability for the wider ecological system, from humans to animals, to prosper and thrive within it from disruption to natural and human-made habitats. Although visual pollution can be caused by natural sources (e.g. wildfires) the predominant cause comes from human sources. As such, visual pollution is not considered a primary source of pollution but a secondary symptom of intersecting pollution sources. Its secondary nature and subjective aspect sometimes makes it difficult to measure and engage with (e.g. within quantitative figures for policymakers). However, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
