Traction current line

The traction current is a high voltage power line to supply trains with traction power. It is not to be confused with the contact wire which supplies directly the electric traction vehicles with power. The traction current is used to supply substations, of which the direct supply AC-driven tracks with single-phase alternating current, which does not correspond to the line frequency of the public grid are.

Are railway power lines, to keep the wiring short and to avoid unnecessary interference of electrical installations in haul, not usually laid parallel to the railway line, although this is technically possible and particularly along suburban train lines will also be made.

The usual voltages are in Germany and Austria 110 kV, 66 kV in Switzerland or 132 kV. In the area of ​​Vienna some traction current lines are operated at 55 kV ( Meidling - Hütteldorf Hütteldorf - Auhof, Hütteldorf - Florisdorf, Florisdorf Simmering Simmering and Meidling ). Some traction current lines for the supply of new lines were sized so that at a later date an operating at 220 kV would be possible ( see figure).

The traction current lines of Germany, Austria and Switzerland are joined together, such as on the traction current Muttenz - Haltingen.

Freileitungsmasten

Traction current lines are usually designed as an overhead line. Cable routes exist only in the vicinity of some power plants and in some urban areas. As pylons pylons are almost always used. In Switzerland, the laying of railway power lines on concrete poles is not uncommon.

A traction current for single-phase has two conductors. A pipeline route usually consists of two independently switchable lines, there are thus four conductors on the pylons (as opposed to alternating current lines, the number of conductors is an integral multiple of three is ).

For traction current lines, which are attached to catenary masts, either the two-level arrangement of conductor cables is used for static reasons, each circuit claimed a pole half or it is in two tracks on the catenary masts, which carry the overhead line for each track, a crossbar for receiving of traction power system ( two conductors ) installed.

In most traction current lines with four conductor cables in Germany and Austria, a level arrangement is performed. In Switzerland, the two-level arrangement of conductor cables is very widespread.

For traction current lines with eight conductor cables is almost always chosen the two-level array, each of the two trusses carries four conductor cables. For traction current lines with eight conductor cables, of which two are systems for the supply of the new line, the three-level arrangement is selected, where two systems are on the lowest crossbar and two systems in the top two traverses space.

There are also traction current lines with twelve conductor cables ( six systems). In these lines, the three-level arrangement ( four conductors per traverse) is almost always applied.

Traction current Möglingen-Vaihingen/Enz, south of Moeglingen. The circuits on the top trusses could be converted to 220 kV

2 hybrid lines in Kornwestheim. The left line carries the circuits of the traction power line Neckarwestheim/Schaltwerk- Stuttgart- Zazenhausen, next to the railway power line GKN - Neckarwestheim / switching mechanism of single rail power cable with four bundles

Traction power quad trunk line Neckarwestheim / traction power rear derailleur - Zentraleinspeisstelle Stuttgart- Zazenhausen. This railway power line is next to the railway power line GKN Neckarwestheim - Neckarwestheim / traction power derailleur the only railway power line with four bundle conductors

Pylon of a 2 - systemigen traction power line, which is equipped as a two - trunk line

Traction current with Verdrillmast far away from railway lines at Bartholomew on the Swabian Alb

Feature: 110- kV high-voltage mast No. 9108 on a shed in the freight station in Fulda.

The foundation of the mast No. 9108 in the shed.

In Mannheim -Friedrich field a traction power line crosses under four systems various other lines at very low single-plane poles.

Swiss railway power line at Rapperswil -Jona.

There are also high-voltage pylons, and which carry both electric circuits for traction current for three-phase, such as along the traction current Rupperswil - Muttenz. In particular, in the vicinity of urban areas, power plants, which provide both traction power and electricity for the national grid and to the joint works of railway companies and electricity companies are those lines to find because there space for overhead lines is scarce. Here, the parallel runs to 110 kV and sometimes to 220 kV AC lines is particularly common. Laying together with 400 kV three-phase circuits on the same mast generally requires an interpretation of the isolation of the traction current for 220 kV, since in case of failure of the 400 - kV line along the traction current line voltage peaks can occur, which is insulated for 110 kV not grown can be. In such lines, the path circuits are at least in the lines realized in Germany almost always in one plane. In Switzerland, the distribution over several trusses is not uncommon in such lines.

The highest railway power poles belong to the western Weser- free line crossings Bremen- industrial port. They serve a vierkreisigen traction power line to cross the Weser. However, four conductors of the Elbe crossing 2 be used as traction current at the time.

Laying along the railway line

In the often performed laying along the railway line, transmission is performed on a truss on the catenary masts above the upper line. Since oberleitungsmasten have a smaller cross-section than traction power poles, the beams are capable of strength reasons have little projections. Therefore, the usual at traction current lines arrangement of four conductor cables separates in a plane from most. Either the catenary masts are then equipped with two tracks for both directions with a crossbar for two conductors, or it is applied a two-level arrangement of conductor cables, each cable system claims a half mast.

Special features / records

• The traction power line that runs along the railway line through the city of Fulda, has 30 consecutive tension towers.
• In addition, a mast of the line (No. 9108 ) is in a storage shed at the Fulda train station and protrudes from the roof.
• The traction current switching Neckarwestheim - Zentraleinspeisstelle Zazenhausen is one of the few railway power line in Germany, with four bundles. Another leads from the rear derailleur Neckarwestheim nuclear power plant Neckarwestheim. The reverse current line of the ICE line to the substation Kreiensen is designed as a four- bundle, but it is part of a catenary power supply and not a traction power line.
• Labeling of a high- voltage pylons DB Energie GmbH (former German Federal Railways and German Bahn AG ) The traction current lines are denoted with metal plates ( black letters on white background), which are about the size of an A3 sheet. On them the pole number (154 ), the operator (DB Energie GmbH ), and the running on this side of the mast systems are mentioned. The name of the first and the last is connected to this system is called substation. Feeders are not mentioned and are themselves with " Abzw - Uw substation name " labeled. In the example picture on the right there are two systems, each with two conductor cables ( "RT "). Both systems have the designation " Priort - Genshagener Heide" and are only by their number system (2, 1 ) are distinguished. Because here, the same start and finish have both systems, which consist of two conductor cables, the name is displayed only once and did not mention the branch to the substation Golm. The signs are placed along the line in the direction of the former substation. The mast numbers are low in this direction and are a one-to five -digit sequential number. This number is not unique in Germany and leading zeros can occur.

Conductors

Traction current lines used in the rule, as most lines with operating voltages of 110 kV no bundle conductors. For the supply of heavily-traveled routes, in particular the new and upgraded lines for ICE operation also two bundles are used. The traction current lines from the nuclear power plant Neckarwestheim for traction current switching Neckarwestheim and from railway power switching Neckarwestheim the central sub-station in Stuttgart- Zazenhausen are designed as four bundles.

Traction current lines are - apart from some of catenary poles laid sections - always equipped with a ground wire. The use of two ground wires takes place in Germany only with laying on hybrid poles, as in the line to the nuclear power plant Neckarwestheim. In Austria and Switzerland, there are also equipped with two earth wires traction current lines.

Operation

Traction current lines are operated symmetrically with respect to ground. In a 110- kV traction power line thus each conductor has a voltage of 55 kV to ground. The ground is made in larger substations and power plants in the web via chokes ( Petersen coil) to clear the ground fault current. As with all symmetric power lines, there are also twists at traction current lines.

Other examples

The operated with single-phase AC with a frequency of 25 Hertz Mariazellerbahn has its own traction current lines with an operating voltage of 27 kV. These cables are attached to the catenary masts above the upper line.

In the areas around New York, there are some tracks that also go with single phase 25 Hertz. These tracks are also equipped with traction current lines, which are usually attached to the catenary masts.

In Italy, until 1977 numerous tracks were operated with AC of 16,667 Hertz. These tracks were its own railway power lines that were operated at 60 kV, fed. Since these lines were carried out as AC lines of the public network, they were far less pronounced than the traction current lines of German speaking countries.

Even with some tracks for 50 Hertz operation, there are railway power lines, for example, exist for the energy supply of some TGV routes single-phase power lines.

Situation with distributed traction power supply

In Sweden, Norway and the north-eastern Germany (mainly Brandenburg and Mecklenburg -Western Pomerania) of the public network extracted phase current is converted to single-phase AC with a frequency of 16.7 Hz in decentralized Bahnstromumformerwerken. In these regions, there is no traction current lines.

Even with railways that operate with direct current or single-phase frequency of the public network, the conversion is always performed in substations, so that here there are usually no train power lines. Exceptions may exist in areas where the electric railway, the first major consumer was so that the railway company only had to supply lines build the power supply or where a Umelektrifizierung of a system was done with central traction power supply into a DC or AC system with power frequency. In all these cases, the traction current lines are three-phase lines.