Wind Power for a More Stable Power Grid

As the amount of wind power is steadily increasing, there is a challenge in that wind power, which is weather-dependent, creates a greater need for ancillary services for the power grid. A stable power grid must always be in balance, and to manage situations such as less wind than expected or various operational stops, reserve capacity and other types of ancillary services are required to ensure that the power grid remains balanced. These ancillary services are procured by the Swedish transmission grid owner Svenska Kraftnät on open markets where different actors can sell, for example, part of their capacity for Svenska Kraftnät to use as needed.

Traditionally, hydropower has provided a large part of these ancillary services, but there is a great need for more actors to contribute. Not least, the wind power sector.

The project will demonstrate that wind turbines can provide the ancillary services requested by Svenska Kraftnät and develop and propose new ancillary services adapted for wind turbines. Ultimately, the goal is for more wind turbines and more actors to contribute ancillary services to the power grid.

The project is a collaboration between Chalmers University of Technology and RISE. The RISE part involves investigating:

• International experiences concerning compensation for reactive power
• Voltage regulation capacity from distributed generation
• Island operation and frequency regulation

What is island operation?

Island operation involves various parts of the power grid being able to function even without connection to the transmission network. This, in turn, requires that ancillary services function to maintain the balance in the part of the network that is under island operation.

What is reactive power?

The power electronics found in modern wind turbines enable reactive power to be controlled towards the overlying grid. Reactive power can be used to maintain voltage (voltage regulation) at a good level on the higher voltage levels of regional grids and the transmission grid.

Why is voltage regulation necessary?

Traditional production facilities have the capability to regulate the voltage in the grid, and as these facilities are sometimes replaced by wind power, the regulation needs to be provided by wind power.