For 20 years, FRP-reinforced polymer composites have been used in electrical applications. These materials are used to make various parts of the electrical industry, including cable crossings, cable carriers in tunnels and bridges, power transmission beams, transverse arms (cross logos), insulators, communication towers, and Except that
One of the uses of composites in the power industry is the construction of cable crossings. GRP-reinforced polymer reinforced polymer pipes can be used in combination with special fittings and accessories to form a multi-layered, multi-row cable system. These pipes are used for urban power network cables and underground telecommunication cables. In addition, they are also applicable to:
1) for cables that run under the rails of the ceiling cranes or main urban roads.
2) for cables that run through bridges and rivers. Particularly for cables that cross the bridge, the use of GRP pipes will reduce the load on the bridge and facilitate the construction of the bridge.
Composite cable carriage systems are a structural product for solving many engineering and design problems in telecommunication and power networks that are reliable in maintaining long-lasting, often highly sensitive, and reliable cables. These systems have unique features that enable them to withstand many corrosive environments, especially where traditional materials do not have a useful lifetime. These products are made of hardened hardened resins of glass and designed in such a way that their structural integrity competes with steel and aluminum types, with the exception that they do not have corrosion problems, heavy weight and electrical conductivity.
These products are resistant to acids, salts, alkalis and a wide range of corrosive environments and chemicals that have severe effects on aluminum and galvanized steel. Even aluminum or coated steel products may be vulnerable to scratches caused during installation or afterwards.
These products have a very high strength ratio compared to steel or aluminum, while they have similar structural integrity.
The composite polystyrene profiles used in these systems have a specific weight of about a quarter of steel and one third of aluminum, which facilitates transportation and installation. Unlike stainless steel, these parts can be cut and pierced locally with hand tools. Since the tray and ladders of this system are non-conductive, there is no concern about the transmission of electricity to the cable system of damaged cables. In addition, it is not necessary to prevent electrolyte corrosion under special conditions. Non-conductivity and non-magnetic characteristics mean that the cable transport system is safer.
In the largest privately-engineered engineering project, the tunnel that connects Britain to Europe has more than 63.3 thousand tons of FRP polled, 1260 kilometers of electrical cables and optical fiber. These cables control lighting, ventilation and communications within the tunnel. 25kV cables supplying the energy of the trains are also carried with these palletized composites. These products are compatible with the following conditions:
The temperature range is 5 to 40 degrees centigrade
Humidity 100 degrees
Wind speed at 359 km / h
Continuous spraying of salt water and even immersion in it
Minimal total cost
Resist static cable loading
Each beam of medium voltage transmission (20 and 33 kV) consists of three main parts: beam, transverse arms and insulators. The transverse arms are usually made of steel. However, in some countries such as the United States, Australia, Canada and parts of Europe, these products are made of composite materials. The use of composite cross-arms instead of metal samples has advantages, including:
Weight Loss: The weight of the transverse metal arms (about 20 kg) is one of the problems of transmission and distribution companies. In regions where it is not possible to use lifting machines for various reasons, such as surface roughness, it is very difficult and dangerous to carry transverse metal arms up to the beam; if the composites have a relatively small weight and easy to carry Is .
Corrosion resistance: Metal transversal arms in a humid and corrosive climate have a relatively short life span. One of the advantages of composite materials is their highly resistant corrosion resistance, which makes them suitable for these areas.
▪ Electrical impedance: Composites can be designed and constructed as insulating materials. This feature reduces the risk of electric shock and short circuit. Perhaps using composite cross-arms, the use of cable-insulators-that actually play the role of insulation between cable and profiles-could be prevented.
▪ Aesthetic: There are always limitations in the construction of metal transverse arms that require the designer to use standard corners. With the use of composites, designs that go beyond being optimal are also beautiful.
▪ Longevity: The length of the composite transverse arm is about three times the lifetime of the metal sample. Due to the longer life and the need for replacement and repair in composites, replacement and maintenance costs will be eliminated.
Reducing interference with radio waves: Radio waves pass through composites without any deviation or failure.
▪ Reduced line loss: Using composite transverse arms will prevent the leakage of electrical current from the line to the bases to some extent, thereby reducing line losses.
In addition to the above, with the use of composite cross-arms, designs can be used that are integrated and do not require mounting of parts.
The use of FRP composite girder is not a new issue in electrical services, however, the FRP transmission beam of 21 to 24 meters in length is another story. FRP beams with one-third of the weight of the wooden beams, the weight of the steel beams and only one-tenth of the concrete beams weights are a very attractive choice for most power supply companies.