| Abstract |
This paper introduces the fault behavior of full bridge modular multilevel converters (MMCs)considering a non-simultaneous blocking of the two half bridges in each sub-module. In order toprotect IGBTs in the full bridge sub-module, both sides of a full bridge sub-module are not blocked atsame time point. It is assumed that the first blocking of both sides is random in each sub-module, sothere are many possible voltages in each arm after the first blocking. Because of this, there are alsomany possible fault current slopes after the first blocking. The influence of this sequential blocking onthe maximum fault current is analyzed. The threshold current, which has to be decreased due to thisphenomenon, is determined. |
