Supplementary Power Control of PMSG-based Wind Farms for System Dynamic Stability

The power system frequency stability depends on system power balance, and the required active power for the power balance can be quickly obtained from the kinetic energy stored in the rotating mass. A power control strategy of the permanent magnet synchronous generator ( PMSG) is presented for the system dynamic frequency support. On the one hand, a supplemental active power control loop is added in the maximum power extraction controller of the grid side inverter. It is used to modify the controller to achieve effective network inertia response because the power system inertia reflects the system property of resisting frequency changes. On the other hand, a supplemental reactive power control loop is added to reactive power controller to improve the system damping characteristics. Finally, the dynamic performances of a typical network containing PMSG-based wind farms are tested using MATLAB/Simulink. The simulation studies illustrate that the network dynamic frequency stability can be improved using the proposed control strategy.