Adaptive deloading of stand-alone wind farm for primary frequency control

Abstract

This paper focuses doubly fed induction generator based variable speed wind turbines to contribute in arresting system frequency decay and provide primary control power upon power imbalances for the provision of an active power reserve. The fuzzy-based control strategy is proposed to improve the primary frequency regulation by wind turbine generator (WTG). Moreover, rotor speed of the deloaded WTG is optimized to extract more rotational kinetic energy from deloaded WTG. Using deloaded operation, WTG can acquire reserve energy which can be used during depressed frequency conditions. In this paper, deloading is adjusted continuously by using fuzzy control so that output power from deloaded WTG increases. The dynamic deloading helps in stabilizing the generator during large load change and increases output power from the deloaded WTG. Hence, proposed fuzzy based dynamic deloading scheme not only increases overall annual capacity factor of wind farm but also reduces the fuel consumption when diesel generators are operated along with wind turbines. In order to get more realistic picture, wake effect of wind turbines is incorporated. In this paper, wind farm integrated stand-alone power system is considered for frequency regulation. The extensive MATLAB simulation results are presented by considering different case studies in support of the theory.