A discrete time-domain model for fast simulation of MMC circuits

Abstract

In this paper, a novel discrete time-domain MMC Sub Module (SM) model is proposed for fast simulation of MMC circuits. Firstly, by using Modified Nodal Approach (MNA), the switch in SM is replaced by a changeable voltage source in series with a resistor. Then the SM model is simplified in form and mathematics expression for fast simulation. Secondly, stability of these algorithms are discussed in detail. It is because applying various numerical integration algorithms to the SM model will get different difference expressions, which may result in stability problem. Finally, the efficiency and accuracy of the model are validated using a 20-level MMC circuit by comparison with commercial simulation software.