Grid support by wind turbines and future trends

The European target of 2020 regarding the renewable energy plants including wind farms will lead to increase the contribution of wind farms to national grid systems. By this, wind farms are not considered as passive loads as were considered in the past, but as power plants which should have the same performance as conventional power plants. This means that wind turbines as components of a wind farm are requested to support the grid when the energy demand rises and during emergency situations. The latter is implemented by fault ride through capability of the wind turbines, improving grid stability. Furthermore, many national grid systems have either low infrastructure or developing new energy projects to accommodate the large penetration of wind farms. Due to this fact wind turbines should have several operation modes by controlling their active, reactive power production in some cases with quick response time. The use of power converters for the interconnection with the electrical network raises power quality issues of the power that is delivered to the grid. In summary, in this paper will be presented the way wind turbines can increase the grid stability and the power quality of national grid systems.