Equivalent Inertia Evaluation of Wind Farm Based on Stabilization Diagram

Aiming at the characteristics of the large-scale power electronic equipment access in modern power system, the inertia is continuously reduced. Based on the stability graph theory, the inertia evaluation method for power electronic system is proposed and designed. The method derives the relationship between inertia and active power from the second-order rocking equation model of the power system. Then, based on the output equivalence principle, the equivalent model of the new energy generation system is established by the synchronous machine rocking model. Further, the combination is stable. The graph method identifies the equivalent inertia of the wind farm and the fan based on the active power of the grid connection point. The simulation and measured tests show that the inertia estimated by this method can effectively adapt to the evaluation of the equivalent inertia of the wind farm, thus significantly improving the level of inertia assessment of the power system.