A Review of Si/WBG Hybrid Grid-Connected Converters for Low-Voltage High-Power Applications

The continuously expanding installed capacity of renewable energy has placed higher demands on the power level of grid-connected converters (GCCs). Consequently, the development of GCCs with higher power, lower cost, and higher performance has become a hotspot in international power electronics research. However, classical GCC technical solutions struggle to meet the trade-offs between multiple performance indicators, including reliability, operating efficiency, power density, power quality, response speed, and cost. To address these issues, an emerging technology involves hybridizing Si and WBG devices in one equipment to combine the high current and high cost-effectiveness of Si inverters with the excellent switching performance of WBG inverters. In this context, this paper reviews in detail the inverters based on hybrid devices (HyDs) and hybrid systems (HySs), which are the two mainstream implementation schemes of Si/WBG hybrid inverters. The latest research on these hybrid inverters is systematically summarized, covering basic principles, hardware design methods, control and optimization strategies, and representative laboratory prototypes. Furthermore, key issues and major challenges in the research and application of Si/WBG hybrid technology are highlighted.