Reactive power capability of doubly fed asynchronous generators

While synchronous generator reactive power capability has been extensively treated in the bibliography, reactive capability of doubly fed asynchronous generator (DFAG) has not yet been studied. This kind of generator is widely used in wind energy, and its reactive power capability must be known in order to plan the reactive capability of wind farms as required by grid codes. Active and reactive power output of DFAGs can be expressed as a function of the terminal voltage and the internal voltage, allowing the graphical representation of the power capability limits in a similar way as the synchronous generator.