Electric railways in Sweden are powered by a single-phase AC supply of 15 kV at Hz, as used in Germany, Austria, and Switzerland. Unlike these countries, the 132 kV traction current grid covers only part of the country, approximately in the north of Stockholm. The grid is fed by frequency converters and lacks direct transmission lines from Norway, which uses the same traction current system. Formerly, the Porjus Hydroelectric Power Station provided electric power to the traction network. In the future, the Älvkarleby Hydroelectric Power Station may be connected to the traction network, as this would increase the stability of the power grid of the railway system. Separate from the 132 kV grid is a 30 kV line connection between the Mon and Varp substations in northern Gothenburg.

The overhead wire system has some differences. It is common for the overhead wire pylons to carry a three-phase AC system. In order to reduce the number of substations, the voltage at the substations for the overhead wire is 32 kV on some lines (AT-System). However, trains require 16 kV, so autotransformers are used, which have a central connection connected with the grounded railway, while the other connections are connected to the 32 kV output. The voltage between the central connection to the phase is 16 kV. The other pole to ground is also 16 kV, but with opposite polarity, and runs along the track on the overhead wires until the separation section. Other lines are fed directly with 16 kV from the substations. However, differential transformers are used for feeding to eliminate jamming signals.

Sites

Decentralized Converter Stations Converter Stations only feeding power into the overhead wire.

Place County Technology Power Year of inauguration Alingsås Västra Götaland Rotary Converter, Static Inverter Alvesta Kronoberg Rotary Converter Älvsjö Stockholm Static Inverter Åstorp Skåne Static Inverter Duved Jämtland Rotary Converter Eksund Östergötland Static Inverter Eldsberga Halland Static Inverter Emmaboda Kalmar Rotary Converter Eskilstuna Södermanland Static Inverter Falköping Västra Götaland Rotary Converter Gällivare Norrbotten Rotary Converter Hässleholm Skåne Rotary Converter, Static Inverter Jakobshyttan Östergötland Rotary Converter Järna Stockholm Static Inverter Kil Värmland Rotary Converter Kiruna Norrbotten Rotary Converter Kristinehamn Värmland Rotary Converter Malmö Skåne Static Inverter Mellerud Västra Götaland Rotary Converter Mjölby Östergötland Rotary Converter Moholm Västra Götaland Rotary Converter, Static Inverter Mora Dalarna Rotary Converter Murjek Norrbotten Rotary Converter Nässjö Jönköping Static Inverter Nyköping Södermanland Rotary Converter Olskroken Västra Götaland Static Inverter Ösmo Stockholm Rotary Converter Östersund Jämtland Rotary Converter Ottebol Värmland Rotary Converter Ramvik Västernorrland Rotary Converter Sjömarken Västra Götaland Rotary Converter Sköldinge Södermanland Rotary Converter Stenbacken Norrbotten Rotary Converter Tornehamn Norrbotten Rotary Converter Uddevalla Västra Götaland Rotary Converter Varberg Halland Rotary Converter Västerås Västmanland Static Inverter Ystad Skåne Static Inverter

Centralized Converter Stations Converter Stations, which also feed power into the 132 kV single phase AC grid.

Place County Technology Power Year of inauguration Ånge Västernorrland Static Inverter Bastuträsk Västerbotten Static Inverter Borlänge Dalarna Static Inverter Boden Norrbotten Static Inverter/ Rotary Converter Häggvik Stockholm Rotary Converter Mellansel Västernorrland Static Inverter Ockelbo Gävleborg Static Inverter

Substations Substations fed from the 132 kV single phase AC grid.

Place County Bäckhaga Örebro Bispgården Jämtland Dalstorp Västerbotten Dockmyr Jämtland Frövi Örebro Gävle Gävleborg Gnarp Gävleborg Habo Uppsala Holmsjön Västernorrland Hudiksvall Gävleborg Jönssen Gävleborg Jörn Västerbotten Kullsbjörken Dalarna Ljusdal Gävleborg Ludvika Dalarna Långträsk Norrbotten Norrfors Västerbotten Odensala Stockholm Ramsjö Gävleborg Ryggen Dalarna Storvik Gävleborg Sundsvall Västernorrland Söderhamn Gävleborg Tierp Uppsala Uppsala Uppsala Viskan Västernorrland Vännäs Västerbotten Älvsbyn Norrbotten Österåsen Västernorrland

30 kV-line Mon-Varp Endpoints of the 30 kV-interconnection Mon-Varp.

Place County Mon Västra Götaland Varp Västra Götaland

Other remarkable points The crossing-point between the traction current power line and HVDC Fenno-Skan 2 is the only crossing point of the HVDC overhead line and single-phase AC overhead powerline in the world. It is located at coordinates ..

The railway on the Öresund bridge is fed with Danish standard voltage, 25 kV 50 Hz AC, which goes along 6 km within Swedish borders. The power is supplied from Denmark. The system limit is at Lernacken, near the bridge abutment.

Two local railways in Stockholm County, Roslagsbanan and Saltsjöbanan, as well as Stockholm Metro and all tramways, run on DC power.

External links Explanation https://web.archive.org/web/20110719062453/http://www.ee.kth.se/php/modules/publications/reports/2010/IR-EE-ES_2010_006.pdf http://www.nth.se/nb/banmatningssystem_nb_web.pdf

sv:Matning av kontaktledning