Integration of DFIG Based Wind Turbine Generator on Small Signal Stability of Power Systems

Compared to the direct-drive synchronous generator, integration of Double Fed Induction Generator (DFIG) have different impacts on power system due to their physical and operational differences. The disturbance occurs in the system due to lack of synchronizing torque and damping torque, and it may lead to instability response in the power system. It can be overcome by integration of the DFIG into power system and excitation controller installed with a synchronous generator. The paper investigates the Small Signal Stability Analysis (SSSA) of power system based on eigenvalue analysis in the time domain simulation. Based on this the effects of the interarea and local area electromechanical dominant modes of oscillations are analyzed, with and without an excitation controller. The SSSA reveals important relationships among state variables of a system, participation factor and gives an insight into the electromagnetic dynamics of the network. It is concluded that the DFIG integration into power system has a beneficial impact on small signal stability. The two area test system is used to illustrate the proposed methods.