Digital output controller design for a wind-induction generator conversion scheme

This paper presents the design of a PI (proportional-integral) digital optimal output controller for a wind energy conversion scheme using induction generators. The controller design is based an the reduced-order discrete linear model, which is derived from the full-order linear model using the dominant eigenvalue technique. The scheme consists of a three-phase induction generator driven by a horizontal-axis wind turbine and interfaced to the utility through a double overhead transmission line. For generator voltage regulation, a static VAr compensator is connected at the generator terminals. The system, together with the designed controller, is tested under different types of large disturbances, such as a 3-phase short-circuit at the generator terminals and wind gusts