Transmission network and substations

Augstsprieguma tīkls AS takes care of the backbone of Latvia’s electricity system, i.e., the transmission network consisting of the 330 kV and 110 kV electricity transmission lines and substations that are necessary for further transmission of electricity to the users of the transmission system, i.e., individual large consumers, producers, and distribution network operators. The company ensures the operation, maintenance, and repairs of high-voltage lines, substations, and distribution points, as well as further development of the transmission network.

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The transmission network links Latvia’s power stations with the energy systems of its neighbouring countries as well as distribution network companies, thus providing the consumers with the necessary amount of electricity in real time, as well as with the possibility for producers to export and for traders to import electricity from the neighbouring countries.

The main parameters of the transmission network are the number of lowering substations and high-voltage distribution points within a certain area, which, in turn, describes the specific demand of electricity capacity therein, and an adequate transmission line (330 kV and 110 kV) networks, which also meets the security and economy of electricity supply criteria. According to the said criteria, the transmission network is considered to be operating close to optimal with development potential, which is reviewed on an annual basis in the Transmission system assessment report as well as in the 10-year development plan of Latvia’s electricity transmission system.

For more efficient maintaining of the transmission network, the operating structural units based on the territorial principle have been divided into:

  • 13 substation groups (for the operation of the 330/110 kV substations and distribution points): Salaspils, Krustpils, Daugavpils, Viskali (Jelgava), Brocēni, Grobiņa, Valmiera, Gulbene, Rezekne, Sloka, Ventspils, Riga (the so called right bank and the left bank [river] Riga), with one base substation in each group;
  • 6 line compartments (for the operation of the 330/110 kV transmission lines): the Riga compartment, Krustpils compartment, Daugavpils compartment, Broceni compartment, Grobina compartment, and Valmiera compartment.

Latvia’s 330 kV power network represents the middle point of the energy system of the Baltic states between its northern and southern parts. All 330 kV substations, except for "Daugavpils", have a dual power supply. The 110 kV network has a circle scheme. The majority of the 110 kV substations have two transformers and a dual power supply.

Number of substations, autotransformers and transformers and installed capacities in 2018

Voltage, kV Number of substations, pcs. Number of autotransformers and transformers, pcs. Installed capacity, MVA
330 16 25 3825
110 123 248 5195,5*
Total 137 273 9020,5

*-110kV transformers and 10kV extra voltage transformers

The length of the power lines in 2018

1 346,43 km
330 kV lines
13,64 km
of which 330 kV cable lines
3893,54 km
110 kV lines
75.43 km
of which 110 kV cable lines
5239,97 km
Total
Scheme of 330 kV and 110 kV electrical power networks
330 kV line
110 kV line
330 kV cable line
110 kV cable line
330 kV substation
110 kV substation
HPP
CHP
330 kV line
110 kV line
330 kV cable line
110 kV cable line
130 kV apakšstacija test
330 kV substation
110 kV substation
HPP
CHP