Control and Experiment of an H-Bridge-Based Three-Phase Three-Stage Modular Power Electronic Transformer

Control and Experiment of an H-Bridge-Based Three-Phase Three-Stage Modular Power Electronic Transformer

Abstract— Control and Experiment of an H-Bridge-Based Three-Phase Three-Stage Modular Power Electronic Transformer. Compared with conventional power transformer, the power electronic transformer PET < Final Year Projects 2016 > or solid-state transformer has many attractive additional features. An H-bridge-based three-phase three-stage modular PET, which consists of an input stage with series-connected H-bridge converters, an isolation stage with several independent dual-active-bridge converters, and an output stage with parallel-connected H-bridge converters. This PET suffers dc-link capacitor voltage unbalancing issue, and the parallel-connected module current unbalancing sharing issue. In this paper, a system control structure is proposed for the PET to deal with these issues. Different input-stage individual module dc-link voltage balancing control methods are analyzed and compared.