| 摘要 |
PCT No. PCT/SE93/00662 Sec. 371 Date Feb. 2, 1995 Sec. 102(e) Date Feb. 2, 1995 PCT Filed Aug. 11, 1993 PCT Pub. No. WO94/06028 PCT Pub. Date Mar. 17, 1994.An electric semiconductor valve (V), for example a valve in a converter for conversion between alternating current and high-voltage direct current, comprises a plurality of semiconductor positions (TS1, TS2, . . . TSN) with mutually series-connected semiconductor devices (T1, T2, . . . TN). With the semiconductor valve energized by an alternating voltage substantially corresponding to the rated voltage thereof, the condition of an optional semiconductor position is checked by generating a test firing signal (FP) and supplying it to the firing channel (L, 1, TCU, 3) of the semiconductor position alone, whereupon an indicating signal (IP) delivered by the indicating channel (TCU, 2, D) of the semiconductor position is studied with respect to time. |
