Robust Output Feedback Control Design for Inertia Emulation by Wind Turbine Generators

• Published in: IEEE transactions on power systems Vol. 36; no. 6; pp. 5056 - 5067
• Main Authors: Morovati, Samaneh, Zhang, Yichen, Djouadi, Seddik M., Tomsovic, Kevin, Wintenberg, Andrew, Olama, Mohammed
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Balanced truncation model reduction; Control theory; Converters; diesel-wind system; Doubly fed induction generators; Emulation; Feedback control; Frequency response; generators; Induction generators; Inertia; inertia emulation; Linear quadratic regulator; Modal analysis; Model reduction; Output feedback; output feedback control; Reduced order models; Reduced order systems; Robust control; Robustness; rotors; Short circuits; Synchronous machines; Turbogenerators; WIND ENERGY; Wind turbines
• ISSN: 0885-8950; 1558-0679
• DOI: 10.1109/TPWRS.2021.3070276

Wind generation has gained widespread use as a renewable energy source. Most wind turbines and other renewables connected to the grid through converters result in a reduction in the natural inertial response to grid frequency changes. The doubly-fed induction generator (DFIG) can be controlled to compensate for this reduction and, in fact, provide faster response than traditional synchronous machines. This paper proposes to design observer based output feedback linear quadratic regulator (LQR) and <inline-formula><tex-math notation="LaTeX">H_{\infty }</tex-math></inline-formula> control laws to realize the inertia emulation function and deliver fast frequency support. The aim is to track the reference speed by a diesel synchronous generator (DSG) in order to reach the desired inertia. The control signal is computed based on a reduced order model using the balanced truncation technique. A comparison with selective modal analysis (SMA) and balanced truncation model reduction techniques is presented. Comprehensive results show the effective emulation of synthetic inertia by implementing the control laws on a nonlinear three-phase diesel-wind system. The proposed technique is analyzed for different short circuit ratio (SCR) scenarios.