A high efficiency three-port power converter for wind generators with energy storage

A high-efficiency three-port power conversion system for wind generators with integrated energy storage is presented, characterized by an Open-End Winding configuration and hybrid Silicon-Gallium Nitride (Si-GaN) technology. It consists of a three-level T-type IGBT rectifier, connected through the open stator winding of an AC generator to a GaN-based two-level inverter/rectifier, which in turn is connected to a battery pack. This configuration allows for very low switching power losses, as the T-type IGBT rectifier operates at a very low switching frequency, while the GaN devices in the two-level inverter/rectifier exhibit minimal switching power losses. The system is managed using purposely developed control techniques, aimed at addressing specific issues related to the proposed structure. Simulations and experimental results demonstrate the consistency of the proposed approach in efficiently managing power flows in a grid-connected wind plant that incorporates a battery pack.