A High-Efficiency GaN-Based Multilevel Converter for Five-Phase Wind Generators with Energy Storage

This paper deals with a comprehensive investigation into the design, modeling and performance analysis of a high efficiency power conversion system for five-phase wind generator with integrated energy storage. The main features of such a system are an Open-End winding configuration and a Silicon-GaN hybrid technology. In fact, the proposed system encompasses a five-leg T-type IGBT rectifier switching at the fundamental frequency, connected to a five-leg GaN-based two-level inverter/rectifier through the open stator winding of an ac generator. Such a configuration results in a three-port power conversion system characterized by very low switching power losses, because the T-Type Rectifier operates at a very low switching frequency, while low switching power losses are achieved in the inverter thanks to the GaN devices. Purposely developed modulation and control techniques are exploited to cope with some specific issues related to the open-end winding structure of such a system. Simulations conducted around a five-phase induction generator showcase the robustness and effectiveness of the proposed approach in efficiently managing a wind plant integrated with a battery pack.