DC-Link voltage ripple minimization in a modular multilevel voltage source converter for HVDC power transmission

This paper presents a method for DC-Link voltage ripple reduction for a recently proposed modular multilevel (M
²
C) hybrid voltage source converter intended for the HVDC market. A mode of operation is described that enables both control of the modulation index and reduction of the DC-Link voltage and current ripple. This is achieved by superimposing multiple triplen harmonic components to the rectified fundamental component synthesised by the M
²
C Chain-Link converter.