The Syserwind test project, done in cooperation with Gamesa and grid operator Red Electrica de Espana (REE), has been operating for the last two years on 15 of Iberdrola's projects in Andalucia, southern Spain.
As part of the Twenties programme, set up by industry players to improve wind energy's integration into the grid, the project created new power-frequency and voltage-control equipment and systems to optimise the connection between wind farms and grids.
The wind farms, with a combined capacity of 480MW, were connected to three points in the 400kV transmission grid operated by REE.
These were equipped with the systems development in the Syserwind project, allowing coordinated work on controlling the power generated by the facilities and altering the energy fed into the grid.
Known as secondary frequency control, this enables the transmission system operator (TSO) to handle unexpected fluctuations in demand, notably by an injection of power when demand rises above levels expectedby the TSO.
In order to preserve the stability and security of energy transmission, the system works to stabilise voltage in a region or zone of the network through the aggregation of several wind farms.
Iberdrola said that the trial project confirmed the technical feasibility of the system, adding that it intended to further develop it for wider use.