Grid-connected variable speed generator application with doubly-fed induction machine

Official URL: http://risc01.sabanciuniv.edu/record=b1169195 (Table of Contents)

The thesis deals with power flow between grid and generator. Possible grid connection concepts are described and the topology of variable speed constant frequency with doubly-fed induction machine is emphasized among different topologies. The dynamical model and power flow analysis are realized to investigate the concept. In literature, the most preferred and implemented control method of doubly-fed induction generator, stator flux-oriented active-reactive power decoupling, is studied, simulated in the thesis and important drawbacks of the method are underlined. A nonlinear controller with disturbance observer is implemented to eliminate the drawbacks of flux-oriented based decoupling of active -reactive power. The proposed method brings in orientation-free and simple implementation to the concept. Stability analysis must be realized to satisfy exponential stability for controller performance and boundness of rotor voltages is provided during simulations.