| 摘要 |
1397746 Inverting LA TELEMECANIQUE ELECTRIQUE 21 July 1972 [28 July 1971] 34337/72 Heading H2F In an inverter comprising at least one pair of main thyristors P1, P2 and at least one pair of commutating thyristors E1, E2 and an oscillatory commutating circuit LC, the thyristors are protected against excessive rate of change of current and voltage by means of inductors l1, 12 and shunt circuits comprising inductive resistors R1, 13 diodes d1, non- inductive resistors r1 and capacitors c1, connected as shown, the main thyristors P1, P2 being bridged by diodes D1, D2, connected as shown. As described, two pairs of main thyristors P1, P2 may form a single phase bridge or three pairs may form a three-phase bridge. Fast-acting fuses F1, F2 are included. The main supply V o may be variable in which case a fixed voltage commutating supply V o1 may be switched in at appropriate times by means of an auxiliary thyristor Th o1 . The action of the inverter is explained by means of waveforms (Fig. 2, not shown). In Fig. 3 (not shown), inductors such as l1 are included between the thyristors and the respective fuse whilst inductor L is replaced by a pair of inductors one on either side of capacitor C. |
