Reduced order state observer based feedback control methodologies for doubly fed induction generator (DFIG)

In this paper, a reduced order state observer for DFIG is designed that estimate the states with just using DFIG's stator voltage and power measurements. Further, the proposed state observer is used to provide two control strategies for Rotor Side Converter (RSC) of DFIG a) state estimator based state feedback control and b) state estimator based vector control. The state observer and controllers were tested for varying wind conditions using a full order dynamic model of DFIG with a real-time simulation platform. The results verify that the proposed state observer can augment existing control for DFIG with better tracking of the system output without the need for feedback measurements, and at the same time it can reduce the controller design complexity. Also, these state estimator based controllers eliminate the need of rotor current sensors for DFIG control.