Affiliations: [a]
Department of Electrical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| [b]
Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran
Correspondence:
[*]
Corresponding author. Ali Mohammad Ranjbar, Department of Electrical Engineering, Sharif University of Technology, Tehran, Iran. Tel./Fax: +98 21 6601 5714. E-mail: amranjbar@sharif.edu.
Abstract: Doubly-fed induction generator (DFIG) is the most commonly used technology for wind power generation due to the variable speed performance, decoupled control of active and reactive powers, and high efficiency. However, the DFIG originally cannot participate in damping of power system oscillations since it is not synchronously connected to the power system. This paper proposes an optimal and robust additional damping controller for the DFIG wind turbine to contribute it to damp power system oscillations. It is a fuzzy logic controller that its parameters are optimally tuned using the genetic algorithm (GA). The proposed controller modifies the DFIG active power output by using feedback from grid oscillations. Here, a comparative study is carried out for different feedback signals to determine the best of them. Comparing the results reveal that the rotor speed difference of synchronous generators is the best feedback signal to damp power system oscillations. Time domain simulations also confirm the effectiveness and robustness of the proposed controller under both the small and large disturbances.
Keywords: Fuzzy logic, damping controller, doubly-fed induction generator, power system oscillations
