Subsynchronous Resonance in Doubly Fed Induction Generator based Wind farms
Methods for proper aggregation of the wind turbines in the farm are investigated. Time-domain studies are performed on the aggregated model connected to a series compensated transmission line to verify the analytical results obtained through the frequency domain analysis. Based on the theoretical analysis, mitigation strategy is proposed in order to shape the frequency behavior of the wind turbine. The effectiveness of the proposed mitigation strategy is evaluated both theoretically through frequency-domain analysis and using detailed time-domain simulations.
generalized Nyquist criterion (GNC).
doubly-fed induction generator (DFIG)
subsynchronous controller interaction (SSCI)
induction generator effect (IGE)
subsynchronous resonance (SSR)
Elnät och komponenter
In line with this trend, wind power has become one of the fastest growing sources of electricity globally over the past 15 years. As a result of this, various researches have gone underway to enhance the energy production, increase the lifetime of the wind turbines and their ability to safely connect to the power system. Modern wind turbines are interfaced with the power system through power-electronic converters to increase their flexibility and functionalities, allow to operate at variable speeds as well as to facilitate grid-code compliance. But an increased penetration level of wind power could compromise the stability of the power system due to various factors including: the intermittent nature of the produced power, reduced system inertia and interactions between power-electronic converters as well as between converters and other passive components installed in the power systems. In particular, the latter has been experienced in a number of actual installations, where the first recorded event occurred in southern Texas in 2009, when a wind farm became radially connected to a series-compensated transmission line. The aim of this thesis is to provide the groundwork for a deep understanding of the root causes of this specific phenomenon. Through system modeling and frequency-domain analysis, the work focuses on the identification of the key parameters that affect the stability of the system, understand their impact as well as proposing effective countermeasures.
Annan elektroteknik och elektronik
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4395
Chalmers tekniska högskola
sal EA, Hörsalsvägen 11, Chalmers
Opponent: Prof. Pedro Rodriguez Cortes, Loyola University Andalucia (LUA), Seville, Spain.