Characteristic of the Equivalent Inertia of PLL-Based DFIG Wind Turbine and Its Impact on System Frequency Dynamic

This paper investigates characteristic of the phase-locked loop adjustment (PLLA) inertial control method controlled generator (DFIG) type wind turbine and its impact on the system frequency dynamic. By considering the influence of the different operation areas and the relevant control, we obtain the equivalent inertia and damping expressions of the DFIG wind turbine and the system equivalent inertia. Then the response characteristics of the DFIG wind turbine are studied. The basic characteristics of the PLLA method are concluded. Finally, the time domain simulations are implemented to validate the results.