Hybrid design of modular multilevel converters for HVDC systems based on various submodule circuits

Jiangchao Qin, Maryam Saeedifard, Andrew Rockhill, Rui Zhou

Research output: Contribution to journalArticlepeer-review

242 Scopus citations

Abstract

The modular multilevel converter (MMC) has become the most promising converter technology for high-voltage direct current (HVDC) transmission systems. However, similar to any other voltage-sourced converter-based HVDC system, MMC-HVDC systems with the half-bridge submodules (SMs) lack the capability of handling dc-side short-circuit faults, which are of severe concern for overhead transmission lines. In this paper, two new SM circuit configurations as well as a hybrid design methodology to embed the dc-fault-handling capability in the MMC-HVDC systems are proposed. By combining the features of various SM configurations, the dc-fault current path through the freewheeling diodes is eliminated and the dc-fault current is enforced to zero. Several MMC configurations based on the proposed hybrid design method and various SM circuits, that is, the half-bridge, the full-bridge, the clamp-double, and the five-level cross-connected SMs, as well as the newly proposed unipolar-voltage full-bridge and three-level cross-connected SMs, are investigated and compared in terms of the dc-fault-handing capability, semiconductor power losses, and component requirements. The studies are carried out based on time-domain simulation in the PSCAD/EMTDC software environment for various SM configurations and dc-fault conditions. The reported study results demonstrate the proposed hybrid-designed MMC-HVDC system based on the combination of the half-bridge and the proposed SM circuits is the optimal design among all evaluated systems in terms of the dc-fault-handing capability, semiconductor power losses, and component requirements.

Original languageEnglish (US)
Article number6899714
Pages (from-to)385-394
Number of pages10
JournalIEEE Transactions on Power Delivery
Volume30
Issue number1
DOIs
StatePublished - Feb 1 2015
Externally publishedYes

Keywords

  • DC-side short-circuit fault
  • Fault clearance
  • Modular multilevel converter (MMC)

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Fingerprint

Dive into the research topics of 'Hybrid design of modular multilevel converters for HVDC systems based on various submodule circuits'. Together they form a unique fingerprint.

Cite this