A rapid simulation method for full-bridge sub-module MMC based on bridge arm equivalent capacitance

Abstract

MMC （modular multilevel converter） contains a large number of switching elements， which brings a huge computational burden to the electromagnetic transient simulation. For this problem， this paper proposes a rapid simulation method for full-bridge sub-module MMC based on bridge arm equivalent capacitance. A modeling method for arm equivalent circuit under normal working state， blocking state and full state was developed， and a simulation model was developed which can accurately simulate electromagnetic transient response of the full bridge MMC. On PSCAD/EMTDC platform， a two-terminal MMC-based DC grid test system was constructed to validate its feasibility. Additionally， the model was compared with the Thevenin equivalent model. The results confirm the accuracy and efficiency of the proposed simulation.

Keywords

• dc power grid
• modular multilevel converter
• bridge arm equivalence
• electromagnetic transient