Modeling of modular Multi-Level voltage source converter

A mathematical model that can distinctly reflect device operation principle is extremely needed for deep research on steady and transient performance analysis, main circuit design, control system design etc. In this paper, by using a combination of switch function and instantaneous power, a mathematical model describing time domain analytic function of Modular Multi-Level Converter was presented. Based on it, the transient value of converter AC and DC voltage, arm voltage and current, sub-module capacitor voltage sum in an arm, sub-module capacitor voltage and current related to main circuit parameter can be calculated. From the calculation and simulation results, it is concluded that the modeling method is available and its calculation results are comparatively precise.