Apparatus and a method for voltage conversion

摘要: An apparatus for converting direct voltage into three-phase alternating and conversely comprises a VSC-converter (8) having intermediate link (9) at least one phase leg (12, 13). Each current valve (14-17) of the legs has semiconductor device turn-off type rectifying member connected in anti-parallel therewith. A transformer (19) two opposite ends first winding (20) thereof to an output (21, 22) each second (23) converter three legs. valves being able conduct block both directions turn on by gate control. The midpoints (27, 27', 27') converters are provided with outputs forming terminal between these outputs.