Investigation of Pole-to-Pole DC Voltage and Circulating Current on Design Requirements of Full-Bridge Modular Multilevel Converter

Paper in proceeding, 2024

The Double Wye Modular Multilevel Converter (YY-MMC) with energy storage connected on the DC-link is increasingly utilized in grid applications to facilitate renewable energy sources integration. This paper investigates the impact of pole-to-pole DC voltage and circulating current on the design requirements of a Full-Bridge YY-MMC (FB-YY-MMC). Starting with providing an overview of YY-MMC configuration and circulating current calculation, this paper tries to identify the optimal pole-to-pole DC voltage and the second-order circulating current amplitude and phase for minimizing the design parameters of the FB-YY-MMC, such as losses, semiconductor ratings, and submodule's capacitor size. Time-domain simulations validate the proposed optimal working points, offering valuable insights for optimizing FB-YY-MMC design requirements in grid applications.