Iceland - Sultartangi

Construction at Sultartangi began in 1997 and the station became fully operational in January 2000. The station utilizes water from the Sultartangi reservoir which was formed when the rivers Thjórsá and Tungnaá were dammed between 1982 and 1984. The Sultartangi reservoir is the longest in Iceland at 6.1 km. A headrace tunnel transports water from the reservoir through Mt. Sandafell to a surge basin on its southwestern side. At the end of the surge basin is the station intake, where penstocks lead down to the two turbines in the powerhouse.

A complete generator and excitation system solution was provided for Landsvirkjun Power at Sultartangi. Two 70MW generators were installed in the powerhouse in 1999 each with a rated rotational speed of 136RPM. The generator rated field voltages and field currents are 221V and 954A respectively. The generators are connected to a high voltage substation which is located close to the powerhouse. The substation has three outgoing transmission lines, one to Burfell Hydro Power Station, one to Hrauneyjafoss Hydro Power Station and one to Substation Brennimelur.

There were two PRISMIC® DCP-SA.2D static excitation systems installed at Sultartangi. Each system has a rated output current of 1050A and a rated field voltage of 245V. The excitation systems have two channels available for generator control, leading to a highly reliable dual-redundant system. The excitation systems were installed in cubicles with front and rear access allowing easy commissioning and servicing. The system was successfully commissioned by the company’s service personnel in 2000.

Key Points

  • Complete generator and excitation system solution
  • Full compliance with Landsvirkjun Power Specifications
  • Equalisation to network voltage before generator synchronisation
  • Automatic regulation of generator terminal voltage being corrected by measurement of reactive current
  • Regulation of generator field current
  • Option to regulate the generator reactive power
  • Power system stabilizers included
  • Rotor and stator over current limiters
  • Over and under excitation limiters
  • Limitation of generator terminal voltage to frequency ratio
  • Operational and fault de-excitation of generator
  • Overvoltage protection of rotor winding
  • Excitation set diagnostics including recording of operation states, control instructions, operational and failure messages
  • Easily accessible test points are provided to enable connection of 3rd party recording equipment
  • Worldwide engineering support with engineers based in UK, Holland, Czech Republic, USA, and Australia