DC capacitor voltage regulation of modular multilevel cascade converter (MMCC-SSBC) for DC-powered data center

摘要

DC 380 V power supply has begun to be used for data centers to save energy and supply high quality power. This paper describes dc capacitor voltage regulation of ac-dc converter using Modular Multilevel Cascade Converters based on Single-Star Bridge-Cells (MMCC-SSBC) without line frequency transformer. The proposed voltage regulation method compares each dc capacitor voltage with the reference value directly. The numerical simulations demonstrated the validity of the control even when 3-phase power consumptions are unbalanced.