3-terminal high power medium voltage grid coupling converter

This paper presents laboratory model and new prototype of 3-terminal high power medium voltage converter as a solution for coupling grids with different parameters and improving grid parameters. This paper presents also results of operation of prototype converter and analysis of different states of its operation. In order to meet requirements of coupling different grids there are four-level three-phase neutral point clamped NPC converters, three-level NPC choppers and series connection of three two-level three-phase converters supplied with MV isolation transformer presented.