The history of the use of overhead lines with self-supporting insulated wires

The pioneers in the use of self-supporting insulated wire is considered to be France and Finland - Energy and designers of these countries were the first in Europe engaged in the development of standards in the design and rules of the device with insulated overhead lines (VLI) and protected (SLD) wires. Subsequently, other countries have developed their air suspension system, but as a rule, are taken as a basis of their already approved for use European standards.

In France, first isolated the HV wire bundles appeared in 1955 and is a copper conductor rubber insulation with a shell made of neoprene. At first they were installed on the facades of buildings, replacing bare copper wires on insulators. Since 1962, as the insulation began to use PVC, which in 1977 was completely supplanted by light-stabilized polyethylene mesh structure. As tokonositelya quickly spread use of aluminum, which is due to its cost and the more attractive relationship between weight and electrical conductivity. Finally, finally, widespread self-supporting insulated wire of the brand "Torsade", produced by the plant "Kubler De Lance", which carries the wire is made of aluminum alloy termouprochnёnnogo "almelek" has a section 54.6 or 70 mm² and are always isolated, ie. to. by French standards is zero bearing current-carrying wire, though grounded at several points.

Development of overhead lines with insulated conductors in Scandinavia pushed the need to reduce the effects of the damage caused by severe climatic conditions in the region. At the same time there is a need more than narrow paths of power lines, especially in dense urban areas.

System engineering stranded cable suspended AMKA began in 1958 in Finland NOKIA KABEL enterprise as a system of overhead wires hanging low voltage. The system is twisted around a bare carrier zero wire insulated phase conductors, insulation which is made of thermoplastic polyethylene. Parallel wires were designed with cross-linked polyethylene Ahkaam brand, as well as systems AMKA-T and T-Ahkaam - insulated suspension cable for tropical areas with high humidity.

Currently AMKA system is equipped with more than 170 km of 0.4 kV overhead line in Finland (80%). AMKA System is applied also in more than 30 countries including parts of the world like South America, Africa, Asia, the Middle and Far East: in Peru - in 1981, in Saudi Arabia - since 1984, in Nepal - since 1986, in the mountain regions of the Himalayas - 1989. The use of insulated wires in the southern and mountainous regions was not a problem, because insulation insulated resistant to UV and ozone.

The need for a medium-voltage insulated wires class was implemented development SAX wires.

The first seal isolated wires overhead 20 kV implemented in 1976 - the so-called PAS system - reinforced aluminum wires in plastic insulation. Later, in 1981, the first SAX system line was built in Finland, where the wire insulation is made of polyethylene. In 1984, in operation passed vibration-SAX system, fitted as protection against electric arc devices.

Currently SAX system implies and includes protected wires insulated with polyethylene silanosshivaemogo equipped with the corresponding overhead line fittings, lightning protection devices, vibration protection and mounting accessories related thereto.

In Sweden, the first SLD appeared in 1985 - 3000 km, in Norway the first SLD - 2000 km, built in 1986.

Since the 90s wires AMKA and SAX have become available and used successfully in Russia, now NOKIA KABEL in 1995 initiated the development of the firm ORGRES set of technical standards for design, construction and operation of pilot lines of the influence of 0.4 kV and in 1996 - the same set of documents to the SLD 6-20 kV.

Currently, there are already insulated Rules for up to 1 kV, with SIP, the validity of which is mounted on 01.01.98 1.01.03 and Rules for the SLD 6-20 kV valid from 1.01.99 on 1.01.04.

Development and design of domestic SIPs were launched in 1987 at Irkutsk cable factory. In 1991, according to TU 16.K71-120-91 were put into pilot production of wire marks Sapta, SASPt, SAPssh and SASPssh. The first insulated using these cables in Russia was installed in the Krasnodar Territory in 1994 in the village of Vasyurinskaya Stanitsa Dinskaya district. Its length is 3.5 km away. Production of wires of Sapta SAPssh and was soon discontinued due to the release of the TU 16.K71-268-98 that have been developed based on the international harmonized standard HD626S1 VNIIKP together with JSC "Sevkabel" and with the participation of the Department of Electrical Networks of RAO "UES of Russia "," Lenenergo ", Institute" Zapadselenergoproekt ".

Length of the Russian distribution network of more than 3 mln.km. The lion's share of them was built in the 60s. Today, more than 125,000 km of 0.4 kV is in disrepair. In pre-perestroika years, it replaced every year about 50,000 km, the last decade has not laid more than 5,000 kilometers of new networks each year. Meanwhile period VLN service, on average equal to 30-35 years, ie In the near future the number of accidents on them will increase in ascending progression. And it is clear that today's re-HVL need to carry on with the application of new technologies, one of which is the use of SIP insulated with, once and for all solve the problems of the accident, the cost of installation and repairs. No wonder these lines abroad are often called maintenance-free.