List of installations for 15 kV AC railway electrification in Sweden

Electric railways in Sweden are powered by a single-phase AC supply of 15 kV at 16+2⁄3 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. Frequency converters feed the grid and have no generation or 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.