Time-Sharing Frequency Coordinated Control Strategy for PMSG-Based Wind Turbine

In order to enable the permanent magnet synchronous generator (PMSG)-based wind turbine (WT) to capture more wind energy while providing fast frequency supports effectively during disturbances, this paper proposes a time-sharing frequency coordinated control (TFCC) strategy. Firstly, a rotor virtual inertia control and a DC-link virtual inertia control are presented, and a new adaptive frequency droop control considering frequency deviation is proposed. Secondly, a novel TFCC strategy, which uses the frequency dead-band to coordinate the frequency regulation priority of above three controls, is proposed. With the proposed strategy, the electrostatic energy stored in the DC capacitor is always first utilized for frequency support, while the rotor rotational kinetic energy is only applied when the DC capacitor energy is used up. Finally, the control performance is studied in PSCAD/EMTDC, whose results indicate that the TFCC has better performance in terms of wind energy harvesting and system stability as compared to traditional coordinated control and cascading control, respectively.