Modeling and control of a cascaded doubly-fed induction generator based on dynamical equivalent circuits

This paper deals with the control of an autonomous cascaded doubly-fed induction generator operating in a variable speed constant frequency mode. The proposed structure is a full stand-alone generating system dedicated to isolated grids in embedded systems or in small scale renewable energy systems such as windmill and hydropower generators. The study is focused on the CDFIG. Its behaviour against several design parameters (numbers of pole pairs and rotor interconnexion) is recalled. A model, based on dynamical equivalent circuits, is also given for the design of the controller. Finally, the synthesized controller is validated by simulations and experimental results.