Indirect Power Control of a DFIG using Model-Based Predictive Rotor Current Control with an Indirect Matrix Converter

A new indirect power control strategy using model-based predictive current control (MB-PCC) is presented in this paper for a doubly fed induction generator (DFIG) driven by an indirect matrix converter suitable for wind energy systems. In this paper the power reference is used to develop a new expression for the stator current in terms of the rotor current. A step by step methodology is presented to generate a dynamic reference for the whole operating regions of the DFIG including synchronization process. Once the reference is generated model-based predictive control (MBPC) is used as it takes into account the nonlinear behavior of the power converter and the discrete-time system model to select the best switching state to be applied in the next sampling period. The switching state is selected using a cost function that minimizes the error between the references and the predicted values. Results are presented for fast and smooth synchronization of the DFIG and flexible active and reactive power control for variable shaft speed to validate the feasibility of the proposed strategy.