Small signal stability improvement of a grid connected DFIG through Quadratic Regulator

In this paper, the small signal stability of a well established Doubly Fed Induction Generator (DFIG) based Wind Energy Conversion System(WECS)connected to the grid is enhanced through an optimal control technique, named, Linear Quadratic Regulator (LQR). The detailed model of the grid connected DFIG wind turbine is described first and then linearize state model is obtained to find the eigen-values. Participation factors at different eigen-values are found and it is identified that which of the state is most participating for the small signal stability of the system. At last, the LQR designed according to the participation factor of the eigen-values, is implemented into the detailed model of the system and the dynamic response of the system has been drawn. The work is performed in the MATLAB
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