Coordinated control of rotor kinetic energy and pitch angle for large-scale doubly fed induction generators participating in system primary frequency regulation

Abstract

This paper presents a control strategy of large-scale wind-thermal power joint primary frequency regulation. First, an integrated control strategy is established rotor kinetic energy control and pitch angle control for wind turbine generators participation in frequency regulation within a wide range of wind velocity; Second, a fuzzy PI controller is designed for the recovery control of the wind turbine, which can avoid the occurrence of the frequency secondary drop accident during the wind generator exits the frequency regulation. Third, an optimal allocation power strategy of wind generator frequency modulation based on weighting factors is proposed in different operating conditions to make full use of the frequency modulation capability of wind turbine rotor kinetic energy control, and the strategy of orderly exiting the frequency modulation of the wind generators is established. Finally, the control framework for proposing the strategy is constructed to enhance the primary frequency regulation ability of large-scale wind generators connected to power systems. The feasibility of proposing the strategy is verified by two examples. The results show that the presented strategy is able to heighten the characteristics of the power system frequency response availably and provide a reference for power system scheduling with large-scale wind power.