Modified Inertia Synchronization Control for a Type-IV Wind Turbine Integrated with a Battery Energy Storage Unit

Inertia synchronization control is a good solution for type-IV wind turbine to provide an inertia response to the grid. To further improve its frequency support performance, this paper addresses a battery energy storage unit on the DC link side of the full power back-to-back wind energy converter. After that, the corresponding modified control strategy is implemented as an upgraded version of existing inertia synchronization control from the view of emulating the behavior of a traditional synchronous generator widely used in power system for decades. Moreover, a control method based on removable virtual resistors co-operated with reconfiguration of battery energy storage unit’s control structure is studied in detail to improve the low voltage ride through performance of the wind turbine. Simulation results are obtained based on the environment of PSCAD/EMTDC, which can certify the correctness and feasibility of the presented control method in this paper.