Investigation of power control on grid on doubly fed induction generators

The increasing energy demand, fossil fuels leads to environmental pollution has increased the interest in renewable energy sources. One of the renewable energy sources is wind power. Doubly-fed induction generators can be used in variable speed constant frequency systems. Hence they are widely used in the modern large wind turbines.In this thesis asynchronous machine dynamic model and drive train model are established and they are integrated with bi-directional back to back inverter, filter, generator output transformer, transmission line. After that complete system model is established in which nominal power is 2 MW. In the system under consideration doubly-fed induction generator is integrated into the grid in a controlled manner.All system is designed in Matlab/SIMULINK. DFIG and drive train model created in mathematical domain, whereas semiconductor switches, filters, transmission line and transformers are created with available models in Matlab/Simulink/SimPowerSystems toolbox. The system is simulated at different rotor speed points. Direct power control methods provided independent control of active and reactive power. Fault ride through scenarios are also investigated as part of study.