A Power Control Strategy for a Hybrid Power Supply System Composed of Open-Winding WFSG and Energy Storage System in Islanding Mode

With the increasing penetration of renewable energy, the inertia of grid is gradually decreasing, and transient support capability is seriously insufficient. In order to enhance the inertia, this paper proposes a hybrid power supply system composed of open-winding wound field synchronous generator (OW-WFSG) and energy storage system (ESS). After the establishment of the OW-WFSG model and analysis of the system power flow, a synchronization control strategy centered on rotor position tracking is designed to realize the power control and transmission. Through the analysis of the active power balance mechanism during transient process, it is proved that the ESS with the proposed control strategy can have the characteristics of synchronous generator, which realizes the further improvement of the grid inertia and transient support capability. Simulation results verify the effectiveness of the proposed control strategy.