Induction generators wind-power

Figure 6.64 Typical power curve for an induction generator of 400 kW at 11.5 m/s wind speed...

Wind turbines driving induction generators (third case), are mostly used in APS applications where voltage is produced by other controllable power sources such as diesel generators. They are directly connected to the grid, and their rotational speed is defined by the grid frequency and their power production level. 

So far, issues related to the frequency stability of an APS have been presented. Maintaining voltage levels in the AC buses of an autonomous power system close to their nominal value is a similar problem. Such an objective can be obtained if equilibrium can be achieved between produced and consumed reactive power in the system. The influence of renewable generators on voltage control depends on the type of the interface used for the connection to the grid. Induction generators in wind turbines or small hydro plants, consume reactive power. A partial compensation can be achieved using local capacitors. Power electronic inverters used for the connection of photovoltaic systems and wind turbines are reactive power neutral. 

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