SUB-MODULE FOR A MODULAR MULTI-LEVEL CONVERTER

摘要

The invention relates to a sub-module (10) for forming a multi-level converter (1) having a power accumulator (11), a power semiconductor circuit (12) which is arranged in parallel to the power accumulator (11) and has controllable power semiconductor valves (14, 15), a first connecting terminal (17) and a second connecting terminal (18), a power accumulator voltage drop at the level of the power accumulator (11) or a zero voltage at the level of the connecting terminals (17, 18) being producible depending on how the power semiconductor valves (14, 15) are controlled. The aim of the invention is to improve said sub-module such that as high a voltage as possible can be generated at its connecting terminals while at the same time increasing its reliability. Every power semiconductor valve (14, 15) comprises a series connection of power semiconductor units (19) that can be switched off and have the same direction of passage, every power semiconductor unit (19) being electrically conducting counter to the direction of passage.