Optimal frequency response coordinated control strategy for hybrid wind-storage power plant based on state reconstruction

Abstract

When wind power and energy storage operate in tandem, their operational state undergoes continuous shifts during dynamic processes. Determining the frequency modulation capability of the combined wind and energy storage system during frequency modulation participation is challenging, often leading to a decline in power generation efficiency. To address this, the current study introduces an optimal frequency response coordinated control strategy for hybrid wind-storage power plants, anchored in state reconstruction. The frequency modulation capability is restructured based on the current state of charge (SOC) of the energy storage system. Subsequently, the equivalent active power reserve demand is evaluated for wind power, leading to the formulation of a wind power reserve active power level and its corresponding operational strategy. For swift active power support, an adaptive virtual inertia control is designed for the energy storage system, contingent on its current SOC. Concurrently, an adaptive virtual inertia control for wind power is developed, grounded in effective kinetic energy. The hybrid wind-storage power plant engages in primary frequency regulation, tailored to the nature of frequency disturbances and prevailing state characteristics. Simulation analyses affirm that this proposed strategy, which takes into account the SOC of the hybrid wind-storage power plant and the power grid's dynamics, offers robust active power frequency support during load disturbances.