Modular Multilevel Converter Models and Simulation Approaches

The electromagnetic transient simulation of modular multilevel converters (mmcs) in high voltage direct current (hvdc) systems is a burdensome task due to their high number of nodes and semiconductor devices. To cope with this issue, scholars proposed over the years several mmc models that implement different trade-offs between simulation speed and accuracy. One of the common traits of these representations is that they simplify the model of the semiconductor devices inside the mmc. Other than providing a thorough review and comparison of the most popular mmc models in the literature, this book proposes a novel mmc simulation approach based on sub-circuit isomorphism. This approach, originally conceived to analyse modular electronic circuits such as random access memories, can be profitably exploited to simulate mmcs, since it exploits the common behaviour of structurally identical sub-modules inside them by clustering them together. As a result, the isomorphism-based approach allows performing detailed, yet efficient simulations of hvdc systems.