Equivalent simulation calculation modeling method for modularized multi-level converter

The invention relates to an equivalent simulation calculation modeling method for a modularized multi-level converter. The modularized multi-level converter is composed of six bridge arms. Every two bridge arms form a phase unit. Each bridge arm is formed by connecting a cascade sub-module and a bridge arm reactance L in series. Each sub-module comprises an insulation gate double-pole thyristor IGBT1, an insulation gate double-pole thyristor IGBT2, a diode D1, a diode D2 and a capacitor C. Each insulation gate double-pole thyristor and one diode are connected in an anti-parallel mode for forming a switching component branch. According to the equivalent simulation calculation modeling method, equivalence is carried out on the sub-modules of the modularized multi-level converter and Dommel equivalent calculation models for the bridge arms, and additional switching component processing is adopted for solving the problem that the switching-on state of a switch tube changes during two simulation moments in the locking phase of the modularized multi-level converter. According to the modeling method, the calculation amount in the simulation operation can be reduced by reducing the number of variable impedance branches in the electromagnetic transient simulation calculation, and therefore simulation of the modularized multi-level converter is efficient, and the calculation result is stable and reliable.