多电平逆变器直流母线主动电压调节系统

This article presents an active voltage regulation system for regulating DC-link capacitor voltages in multilevel inverter (MLI) topologies. These voltage levels typically originate from a single DC source and multiple capacitors. Effective regulation is essential for maintaining AC waveform quality and minimizing harmonic distortion. The work includes the analysis, design, and experimental validation of a closed-loop active voltage regulation system based on a buck-boost voltage balancer for a two-capacitor DC link. The system is integrated into an asymmetric T-type MLI, suitable for photovoltaic applications. A closed-loop stability analysis is conducted for general load conditions, and the inverter DC-link current demands are evaluated for compatibility with the active voltage regulator. Experimental results demonstrate accurate AC waveform reconstruction, reduced harmonic distortion, elimination of DC offsets, and fast, robust dynamic response, highlighting the system suitability for high-efficiency MLIs.