Effect of wind farms with doubly fed induction generators on small-signal stability — A case study on Australian equivalent system

This paper presents the influence of large wind power penetration on low frequency oscillation damping characteristics of a large scale system. The system under study is the 14-Generator South East Australian equivalent system. Damping performance of the system under pre- and post-wind scenarios are comprehensively compared. Eigenvalue analysis of a linearized system has been used for this comparison. Different level of wind power penetration has been considered to identify its potential impact on small signal stability of the system. The location and installed capacity of these wind farms have been selected based on their actual geographical location and their point of coupling has been decided based on the nearest available bus of the test system. Aggregated doubly fed induction generators (DFIG) has been used to simulate wind farms. The results indicate that with large wind generation, displacing key synchronous generators considerably influence inter area modes. In the event of contingency the values of these modes fall sufficiently below an acceptable level. However, it has been shown that coordinating stabilizer of those key synchronous generators with voltage control loop of DFIG can improve damping performance of the system.