Discrete Real-Time State Observer Based Feedback Control Methodology for Doubly Fed Induction Machine

In this paper, a discrete form of reduced order state observer for Doubly Fed Induction Generator (DFIG) is designed that estimates the machine states and rotor currents using stator voltage and power measurements. Further, the proposed state observer is used to provide a state feedback control strategy for Rotor Side Converter (RSC) of DFIG. The state observer and controller were tested on varying operating condition in Hardware-in-the-Ioop (HIL) simulation platform. The results verify that the state observer can be used in existing form of control for DFIG with better tracking of output and at the same time reduce the complexity and need for measurements. Also, these state estimator based controllers eliminate the need of rotor current sensors for DFIG control.