ANALYSIS OF GRID INTEGRATED DFIG BASED WIND ENERGY CONVERSION SYSTEM

Abstract

The last decade has seen a manifold increase in the use of renewable sources of energy. With dwindling coal reserves, there looms an energy crisis in the future if the renewables are not utilized effectively and efficiently. Wind Energy has risen as one of the most developed renewable energy source. The global installed capacity of wind power is increasing year after year. This thesis deals with the modeling, simulation and analysis of a grid connected wind energy conversion system employing a variable speed variable pitch wind turbine. These wind turbines are normally realized using a doubly fed induction generator (DFIG), especially for multi-megawatt systems. The various generator topologies used in wind energy conversion systems are discussed with special emphasis on the DFIG. The DFIGs have become a cost efficient and reliable system to extract power from wind. A detailed model of the electrical and mechanical systems of the DFIG connected to the grid is developed using the simulation tool Matlab/Simulink. The thesis presents a complete insight into the steady state as well as dynamic performance of the DFIG. The control structure has been explained in a very detailed manner and its robustness has been investigated under normal and abnormal conditions at the grid side.