Analytical Chip Area Optimization of SiC Half-Bridge MMC-Submodules Covering all Operating Points

Abstract:
With a steady growth in long distance onshore power transfer, HVDC transmission, in which modular multilevel converters (MMC) play an important role, is a suitable solution. The losses of the two switches of a half bridge MMC-submodule are not distributed equally, which allows an asymmetric chip area distribution between the two switches of the half bridge. This publication presents an analytical approach for a chip area optimization of a SiC-MOSFET based half bridge MMC-submodule covering the whole operating range. The analytical approach is based on a mathematical average loss model and does not require any knowledge of the semiconductor specific staic and dynamic characteristics as well as thermal boundary conditions.