A hybrid modular multilevel converter with reduced full-bridge submodules

Rui Li, Lie Xu, Lujie YU, Liangzhong Yao

Research output: Contribution to journalArticle

28 Downloads (Pure)

Abstract

A hybrid modular multilevel converter (MMC) with reduced full-bridge (FB) submodules (SMs) is proposed, where a high voltage rating half-bridge (HB) based MMC is connected in series with a low voltage rating FB-MMC in parallel with a fault breaking circuit on its DC side. Unlike conventional hybrid MMCs with mixed HB and FB SMs, the proposed topology uses the DC capacitor in the fault breaking circuit to block DC faults, while the FB-MMC only commutates the fault current from the FB-MMC to the fault breaking circuit. Thus, the proposed converter only requires around 10%-20% FB SMs, leading to reduced capital cost and losses compared to typical hybrid MMC. The optimal ratio of the FB-MMC and HB-MMC is assessed and comparative studies show superiority of the proposed topology over other alternatives. A case study with 10% FB SMs demonstrates the validity of the proposed hybrid MMC for DC fault blocking and post-fault system restart.
Original languageEnglish
Number of pages10
JournalIEEE Transactions on Power Delivery
Publication statusAccepted/In press - 25 Nov 2019

Keywords

  • DC fault
  • DC circuit breaker (DCCB)
  • HVDC transmission
  • hybrid multilevel converter
  • modular multilevel converter (MMC)

Fingerprint Dive into the research topics of 'A hybrid modular multilevel converter with reduced full-bridge submodules'. Together they form a unique fingerprint.

Cite this