Full Power Compensation Configuration for Weak Grid Voltage Sag Based on Flywheel Energy Storage

摘要

Quick charging stations for electric vehicles with large capacity would lead to voltage fluctuation and sag in the grid. A grid-connected topology based on flywheel energy storage is proposed to suppress voltage sags. The converter model is analyzed and the charging and discharging strategy of the flywheel energy storage structure is studied. The system based on the flywheel energy storage can compensate the active and reactive power of the power network, so it is more conducive to the stability of the power network and voltage regulation. This paper analyzes the influence of active and reactive power on power grid voltage, and proposes the coordinated control of active and reactive power to compensate power grid voltage. Simulation results show that the proposed flywheel grid-connection control strategy can effectively suppress the grid voltage sag caused by the instantaneous access of large load, and can support the grid voltage for a long time.