New technical solution to balance the grid on the west coast

Fingrid is building a synchronous compensator at the Jylkkä substation in Kalajoki. A synchronous compensator is a large synchronous machine without an energy source. This solution will ensure the reliable operation of wind power production, which is highly centralised on the west coast, and improve the system security of the main grid in the region. The synchronous compensator will be commissioned in 2025.

The unprecedented growth in wind power on the west coast is making it difficult for the grid to function in a balanced way. At the moment, 2,300 megawatts of wind power production is under construction and in operation near the Jylkkä substation in Kalajoki alone. Fingrid is ensuring the system security of the main grid and the reliable operation of wind power in the area by building a synchronous compensator at the Jylkkä substation. A synchronous compensator is a large synchronous machine without an energy source.

The large amount of wind power in the area presents a challenge for the power system. Wind turbines are connected to the grid via frequency converters. Frequency converters do not react to changes in the grid’s frequency or voltage with intrinsically rotating masses like conventional power plants. In the absence of characteristics that inherently maintain a balance, the power system becomes considerably more vulnerable to disturbances and more difficult to manage.

When wind power output is high and, in particular, during network outages, the regional electricity network can become unstable. In the worst cases, frequency converters no longer remain connected to the grid. This phenomenon has also been known to occur under normal operating conditions in Finland and elsewhere in the world.

A synchronous compensator stabilises the grid’s voltage and frequency. Fingrid estimates that a synchronous compensator could reduce the need to restrict wind power output by approximately 800 megawatts.  The synchronous compensator at Fingrid’s Jylkkä substation will be commissioned in 2025.

Fingrid is also studying other solutions to tackle the challenges posed to the power system when the network is dominated by wind power. See our previous press release for further information:

Fingrid looking for solutions to the main grid transmission capacity challenges on the west coast >

Further information:

Timo Kiiveri, Senior Vice President, Fingrid Oyj, puh. 040 543 3039