| 摘要 |
1,166,837. Control of D.C. motors; converting. ALLGEMEINEN ELEKTRICIT€TSGES. 21 Oct., 1966 [22 Oct., 1965], No. 47299/66. Headings H2F and H2J. In a system in which D.C. traction motors 3 . . . 6 are energized from controlled rectifier circuits V . . . VIII supplied via transformers 116 either directly from an A.C. supply or from a D.C. supply 1 via inverters I . . . IV, the inverters are controlled by unspecified timing circuits IX . . . XII so that the A.C. output of one pair is phase-displaced by 90 degrees from that of the other, thus smoothing the current drawn from the D.C. supply when the rectifiers are conducting for less than complete halfcycles. Chokes 10, 11 provide further smoothing. A series/parallel switch 9 caters for two levels of D.C. supply, and the transformers have tapped secondaries for the A.C. case. The rectifier circuits comprise bridges having two thyristors and two diodes, the latter acting as freewheeling diodes, and there are smoothing chokes 106 . . . 109. Each inverter has thyristors 16 . . . 19 (inverter I), commutating capacitors 64, 65 blocked by diodes 48 . . . 51, commutating chokes 72, 73 and smoothing capacitors 118, and the energy stored in the commutating capacitors, and also reactive current from the rectifiers reflected through the transformer is passed to the supply via diodes 32 ... 35. Reference has been directed by the Comptroller to Specification 1,009,071. |
