Modeling and Current-Mode Control of a DC–DC Modular Multilevel Converter

This article presents a dynamic model and a current-mode control for a dc-dc modular multilevel converter with the ultimate aim of expanding the converter to a three-leg configuration to reduce the filtering requirements of the dc ports. A complete model of the converter including a systematic approach for the control of the power throughput is developed. It is then shown that the expansion from a single-leg to three-leg configuration requires no additional modeling, and that the three-leg converter significantly alleviates the filtering requirements on both the high-voltage and low-voltage sides. The proposed model and control technique are verified using simulation results based on the MATLAB / Simulink software environment for both the single and three-leg configuration. Further verification is carried out through a single-leg 1-kW experimental prototype.