Operation of Wind Energy Installations During Power Network Disturbances

The response of wind energy installations to grid disturbances is studied in this panel session contribution. In particular, the transient stability influence of a wind energy installation on a nearby grid with a synchronous generator unit is studied. Both fixed-speed as well as variable speed turbine installations are treated. For the variable-speed turbine installations, the influence of using various levels of reactive power infeed from the wind energy installation is investigated. The idea is to use the power electronic hardware that anyway is available in modern wind turbines to make the turbines to, in addition to the normal active power production, also work as STATCOM units. The Cigre 32-bus test system is used to form a case study. The results found were that improvements can be obtained by using variable speed turbines instead of fixed-speed turbines, and further improvements could be obtained by using reactive power infeed from the wind energy installation instead of constant power factor operation.