The traditional Thevein/Norton equivalent Modular Multilevel Converter (MMC) modeling method can provide qualified accuracy in converter-level modeling. Nevertheless, when doing simulation of high voltage muti-terminal DC (MTDC) system, there are too many MMC sub-modules participate in the operation, the computer will consume a lot of computing time for voltage sorting computation of each sub-module capacitor. As a consequence, when doing simulation in MTDC system, it is often impossible to perform simulation operations because too large the computational load. This paper provides a MMC modeling method without considering capacitor voltage sorting process, and meantime maintains high DC side output ripple characteristics. This proposal can satisfy the simulation in system level, applicable for mater-slave control strategy and provide high calculation accuracy even in short simulation running time.

MMC, Fast Modeling, output ripple characteristics