Galvanically isolated modular converter. Issue 12 (1st October 2016)

• Record Type: Journal Article
• Authors: Christe, Alexandre; Dujic, Drazen
• Is Part Of: IET power electronics. Volume 9:Issue 12(2016)
• Page Start: 2318
• Page End: 2328
• Publication Date: 2016-10-01
• Subjects: power convertors -- power grids -- power transformers; galvanically isolated modular converter -- direct current electrical grid -- DC electrical grid -- low voltage telecom distribution system -- LV telecom distribution system -- point‐to‐point high voltage DC transmission -- medium voltage domain -- protection technology -- conversion technology -- bidirectional galvanically isolated high power converter -- MVDC grid -- LVAC grid -- line frequency transformer into -- modular multilevel converter -- MMC; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2015.0747
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : Direct current (DC) electrical grids are already a reality in low voltage (LV) telecom distribution systems and point‐to‐point high voltage DC transmission. Medium voltage (MV) domain, despite its big potential, still suffers from a lack of suitable conversion and protection technologies. This study presents a bidirectional, galvanically isolated, high power converter for interface of emerging MVDC grids with readily available LVAC grids. To achieve high conversion efficiency, the integration of a line frequency transformer into the structure of the modular multilevel converter (MMC) is analysed and described in a systematic manner. Two configurations of the galvanically isolated modular converter: (i) interleaved and (ii) stacked, are derived and presented. Differences and similarities, compared to the classical MMC, are presented on the system design level, while control performances are evaluated by means of simulations.