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Wang, Zhongxu

PROJECT TITLE: Mission Profile based Control and Reliability Improvement Strategies of Modular Multilevel Converter

PhD period: 2016.11.01 – 2019.10.31.
Section: Power Electronic Systems
Research Programme: Efficient and Reliable Power Electronics
Supervisor: Huai Wang
Co-Supervisor: Frede Blaabjerg
Contact Information

Collaborator: Harbin Institute of Technology.
Funding: China Scholarship Council (CSC), Center of Reliable Power Electronics (CORPE).


Modular multilevel converter (MMC) has become a promising modular topology in high power systems like high voltage direct current transmission (HVDC) and wind power generation, where reliability is of great importance due to the large number of submodules and corresponding high cost in the large-scale power transmission systems. To enhance the overall reliability of MMC, various approaches can be adopted like redundancy strategy, while extra hardware cost will be brought into the MMC system. However, optimized reliability oriented control method can be an alternative for the improvement of reliability performance, which has limited study in the state-of-the-art research.

This project will focus on mission profile based control methods and reliability improvement strategies from operational management perspective, considering switching frequency, modulation technique, circulating current, capacitor voltage ripples, etc. to relieve the thermal and electrical load on power semiconductors and passive components, which have significant effect on reliability of MMC systems. The electro-thermal stresses of key components will be experimentally measured from a scale-down MMC prototype to verify the effectiveness of different reliability improvement strategies.  


Publications in journals and conference papers may be found at VBN.