Delta-sigma modulators for modular multilevel converters

Modular multilevel converters (MMC) are emerging to be an alternative approach for realizing power converters for a variety of high power applications because they allow series-cascaded levels and/or parallel-connected branches. However, the design of communication interface between system controller and individual modules became increasingly complicated as more modules been added into the system, and advantages brought by the MMC topology become compromised by the disadvantages from its data connection complexity. This paper aiming at reduce communication stress by using delta-sigma (or sigma-delta) modulation (DSM) strategy, and carrying out studies from the aspects of both performance and feasibility with classical approaches.