Wind Mills and Transmission System Interaction

Abstract

This thesis report focuses on different kinds of power system disturbances and their impact on voltage profile at the point of wind power connection. The study of the different wind turbine types is made to find out their low voltage ride through capability. Finally, the behaviour of wind turbines at the point of grid connection is analysed vis-à-vis the effect of the different wind turbine types on the voltage profile. Electric power systems comprise more and more wind power, connected one by one or in small groups (a few MW), in the distribution system, or in large farms (hundreds of MW) connected to the subtransmission or transmission systems. For large hydro and thermal generators, there have been rather strict rules on the so called “ride-through” capability, i.e. the generator must not trip for certain faults in the power system or for certain voltage profiles in the point of connection. Similar requirements have not been essential for a small number of wind power generators, connected to the distribution system. However, the number of distribution system based wind power generators is increasing considerably and their total impact on the main grid is crucial.