| Abstract |
A hybrid arm MMC with half-bridge arms close to the grounding pole and full-bridge arms away fromthe grounding pole is studied. Different operating modes of the converter in dc fault blocking state areexplained. For each operating mode, the differential equation of fault current is derived. Then, thesufficient condition for blocking the fault current is extracted. Also, a mathematical formula isintroduced for the estimation of maximum blocking time. Finally, the STATCOM operation in thefault period and smooth voltage build-up capability of the hybrid arm MMC are explained. Alltheoretical claims and the converter behavior are verified by simulations. |
