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