Multilevel Converter Topologies Evaluation for Superconducting DC Transmission Systems

Multilevel converter topologies present significant advantages for high-power transmission and are recently adopted within modern direct-current (dc) transmission systems. Moreover, superconductivity provides the additional benefit of near-zero transmission losses. In this paper, basic advanced multilevel converter topologies that are commonly used in conventional HVDC applications, and their operation characteristics are presented and analyzed. Moreover, focus is given on their integration into a point-to-point superconducting dc transmission system. Results are gathered together in order to compare and evaluate the performance of the examined topologies in superconducting dc links. Impact on filters and system passive elements' sizing is also discussed. Finally, suggestions for the most suitable converter topologies for superconducting dc systems are made.