| 摘要 |
The invention relates to a VSC-converter for converting direct voltage into auxiliary voltage and vice versa, which comprises a series connection of at least two current valves ( 5, 6 ) arranged between two poles ( 7, 8 ), a positive and a negative, of a direct voltage side of the converter, each current valve comprising several series connected circuits ( 12 ), each of which circuits comprising a semiconductor component ( 13 ) of turn-off type and a rectifying component ( 14 ) connected in anti-parallel therewith, an alternating voltage phase line ( 16 ) being connected to a midpoint ( 15 ), denominated phase output, of the series connection of current valves ( 5, 6 ) between two of said current valves while dividing the series connection into two equal parts. Each of the series connected circuits ( 12 ) of the respective current valve comprises, in order to make possible a good voltage distribution between the semiconductor components ( 13 ) of turn-off type included in the respective current valve, a snubber capacitor ( 17 ) connected in parallel with the semiconductor component ( 13 ) of turn-off type included in the circuit. The converter ( 1 ) further comprises a resonance circuit ( 18 ) for recharging the snubber capacitors ( 17 ) of the current valves. |
