Multiport DC-DC Modular Multilevel Converter for MVDC and HVDC Networks

  • Author / Creator
    Kung, Sunny
  • This thesis proposes a multiport dc-dc modular multilevel converter, which is the first truly modular solution for a \"dc hub\" that can interconnect multiple MVDC or HVDC systems in future dc grids. The proposed converter, termed MP-DCMMC, consists of modular subconverters that can be added to or removed from the power circuit without critically affecting overall converter operation. When compared with existing multiport solutions for MVDC or HVDC grids, the MP-DCMMC is more accommodating to future grid expansions, has improved reliability by eliminating the requirement of a centralized ac-link, and is more tolerant to component failures within the converter. This thesis develops the general structure, principles of operation, design procedure and control strategies for the MP-DCMMC and two types of its subconverters. The validity of realizing a dc hub with the MP-DCMMC is verified through extensive time-domain off-line simulations in PLECS across a wide range of operating points. A comparative analysis between the MP-DCMMC and existing multiport solutions is conducted based on converter modularity, component cost, and fault-blocking capability.

  • Subjects / Keywords
  • Graduation date
    Spring 2018
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
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