公开(公告)号：JPH09140141A

公开(公告)日：1997-05-27

申请号：JP22366096

申请日：1996-08-26

Applicant: ABB MANAGEMENT AG

Inventor： PEETAA DEERAA ,  OZUBUIN GAUTSUPU ,  GERUHARUTO OO RINHOTSUFUAA ,  KURISUTOFU CHIYUUDEII

IPC: H02M1/06 ,  H02M7/12 ,  H02M7/155

Abstract: PROBLEM TO BE SOLVED: To provide a common turn-off circuit for a thyristor power converter. SOLUTION: A common turn-off circuit 1 is suitable for an AC converter especially for connecting a railroad network, for example. Turn-off thyristors (TL+, TL-) are connected directly to the secondary winding of a transformer 7. Further, the circuit is provided with specific free wheel paths (DF, RF) to extract an energy accumulated in an inductor especially for a transformer or a related inductor. The circuit 1 has a function to complete a turn-off operation automatically, so that all thyristors for a power converter 2 can be turned off securely and without special preventive measures. Further, the overvoltage can be prevented thanks to the special free wheel paths.