New voltage compensation of a standalone CDFIG supplying unbalanced loads

Abstract Brushless doubly fed induction generator has demonstrated potential capabilities in renewable energy and embedded power generation applications. As a standalone system, it exhibits unbalanced output voltage and poor performance under unbalanced loads. The main objective of this paper is to address the imbalance problem and compensate the output voltage unbalance of the standalone generator. The suggested strategy is developed based on dual rotating frames. A main controller and an auxiliary compensator are proposed to control respectively the positive and the negative sequence components of the machine quantities. The main controller is implemented in the positive frame without involving sequence decomposition. The auxiliary controller is implemented in the negative frame to eliminate the negative component of the unbalanced stator voltage. Experimental results are presented to validate the proposed control scheme and to show the enhanced operation of the system during unbalanced conditions.