Frequency Active Support Control Strategy for Wind Turbine and Energy Storage Coordination Based on System Inertia

The large-scale application of wind power has relieved the pressure of conventional energy shortage, but it cannot adjust frequency, which has brought great hidden dangers to the safe and stable operation of the power grid. When using the rotor kinetic energy to participate in the system frequency regulation, the Doubly-Fed Induction Generator can effectively respond to frequency changes, but there are problems of secondary frequency drop and output active power reduction when exiting frequency regulation, and cannot provide energy support for a long time. Aiming at this problem, based on the analysis of the system inertia demand, this paper firstly analyzes the inertia support capacity of the rotor kinetic energy and energy storage, and finally proposes a wind-storage coordination frequency active support control strategy based on the system inertia demand. The rotor kinetic energy and energy storage are used to achieve inertia characteristics and droop characteristics similar to synchronous generator sets, respectively. The coordination of the two ensures that the wind generator set can provide fast and lasting power support when the system frequency fluctuates.