Hólar

At the end of 1992, the first Series Capacitor in Iceland was commissioned in the 132 kV network of Landsnet, the National grid company, less than a year after the awarding of the contract to Hitachi Energy.

The Icelandic 132 kV grid forms an extensive ring around the country, and ties into the 220 kV system in the southwestern part of the territory. The Series Capacitor is located at Hólar substation in the eastern part of the 132 kV system, where power generation is low.

The Series Capacitor is rated at 43 Mvar at 132 kV. It compensates approximately 70% of the line reactance oft the 132 kV line between Hólar substation and Sigalda, the site of 150 MW hydro generation. The purpose of the Series Capacitor is to increase the power transmission capability and stability of the 132 kV line.

The Series Capacitor is protected against overvoltages due to faults elsewhere in the system by means of a gapless scheme comprising a zinc-oxide varistor in parallel with the capacitor bank. For faults external to the compensated line section, the varistor is able to absorb all the energy diverted into it, without any need to bypass the Series Capacitor.