A Three-Terminal Output AC/DC Converter With Automatic Power Decoupling and Common Ground

As the search for sustainable, environmentally friendly energy sources continues, DC devices such as new energy-electric vehicles and energy-saving LED lights have been actively promoted. Consequently, the necessity for the DC microgrid in grid system development will become increasingly apparent, and the research on three-terminal output converters is increasing. Besides, double-frequency ripple power is an inherent problem in single-phase power electronic systems. This paper proposes a three-terminal output AC/DC converter with automatic power decoupling and common ground for the DC microgrid as a solution to the issues above. The equivalent circuit has been subjected to a detailed analysis to elucidate its underlying operating principles. Due to the structure of the common ground, the common mode leakage current can be eliminated in this converter. In addition, the implementation of automatic power decoupling enables the replacement of electrolytic capacitors with film capacitors, leading to higher power density and longer lifespan. Furthermore, the employed deadbeat control has a fast dynamic response capability. Finally, the simulation results are presented to verify the theoretical analysis and the performance of this converter.