Compensation of voltage unbalance of a standalone CDFIG using repetitive rotor current control

This paper analyzes the unbalance problem of a standalone cascaded doubly-fed induction generator feeding unbalanced three-phase load. Under this working condition, the output voltages become un-balanced and give rise to a negative sequence component. The classic vector control strategy does not provide the desired performance. A compensation method is proposed to balance the stator voltages. The approach is developed based on a repetitive rotor current control implemented in a single positive reference frame. Simulations attest of the ability of the controller to reject the unbalanced load impact on the generated voltages.