Improved Power Decoupling Scheme for Single-Phase Grid-Connected Differential Inverter with Realistic Mismatch in Storage Capacitances

Research output: Research - peer-reviewJournal article

Abstract

A single-phase differential inverter consists of two elementary dc-dc converters, sharing a common dc source and a common ac output terminal. The other ac terminals of the two converters are connected to the grid in the case of grid-connected applications. The differential inverter has subsequently been shown to have a differential flow path for power transfer and a common-mode path for shifting the usual second-order power oscillation away from the dc source. This capability is referred to as power decoupling, which when implemented properly, may prolong the lifespan of the dc source. Existing studies related to power decoupling using a differential inverter have however focused on developing control schemes with equal storage capacitances assumed for the two elementary converters. This is unquestionably not realistic since the two capacitances will vary in practice. It is therefore the intention of this paper to quantify ac and dc imperfections experienced by the differential inverter when storage mismatch occurs. A simple improved scheme is then proposed for raising performance of the differential inverter (or the differential rectifier where desired). Simulation and experimental results provided have verified the computation and control scheme developed.
Close

Details

A single-phase differential inverter consists of two elementary dc-dc converters, sharing a common dc source and a common ac output terminal. The other ac terminals of the two converters are connected to the grid in the case of grid-connected applications. The differential inverter has subsequently been shown to have a differential flow path for power transfer and a common-mode path for shifting the usual second-order power oscillation away from the dc source. This capability is referred to as power decoupling, which when implemented properly, may prolong the lifespan of the dc source. Existing studies related to power decoupling using a differential inverter have however focused on developing control schemes with equal storage capacitances assumed for the two elementary converters. This is unquestionably not realistic since the two capacitances will vary in practice. It is therefore the intention of this paper to quantify ac and dc imperfections experienced by the differential inverter when storage mismatch occurs. A simple improved scheme is then proposed for raising performance of the differential inverter (or the differential rectifier where desired). Simulation and experimental results provided have verified the computation and control scheme developed.
Original languageEnglish
JournalI E E E Transactions on Power Electronics
Volume32
Issue number1
Pages (from-to)186 - 199
Number of pages14
ISSN0885-8993
DOI
StatePublished - Jan 2017
Publication categoryResearch
Peer-reviewedYes

    Research areas

  • Active power decoupling, Differential inverter, Active damping, Storage capacitance, Grid connection
ID: 227009173