| 摘要 |
1,181,800. Converting; control of motors. BRITISH IRON & STEEL RESEARCH ASSOCIATION. 22 Dec., 1967 [23 Dec., 19661, No. 57783/66. Headings H2F and H2J. A current converter comprises a plurality of groups connected in series, each group including the parallel combination of circuits, each consisting of a transformer secondary winding 1S, connected in series with a controlled rectifier 1S1t and a further rectifier shunting each group and operable to pass current in the same direction as the controlled rectifier. As shown, two such sets of groups are connected in parallel and control the supply to a D.C. motor. The secondary windings in each vertical column are arranged to be in phase, the windings in the respective vertical columns being coupled to primary windings of a six-phase system, the two sets of groups being conductive alternately. The voltages of the secondary windings in the respective groups are related on a binary scale. The voltage supplied to the D.C. motor is thus a function of which controlled rectifiers are triggered so as to be conductive, the other groups being by-passed by the uncontrolled rectifiers. In Fig. 1 (not shown), a single set of groups is used, each group consisting of the parallel arrangement of six series circuits each having a transformer secondary and a controlled rectifier. Fig. 4 (not shown), relates to an arrangement in which each controlled rectifier is shunted by an inverse controlled rectifier and each group is shunted by a pair of inverse controlled rectifiers. Such an arrangement can supply power of either polarity to a reversible D.C. motor or three-phase supply of variable frequency to an A.C. motor. In Fig. 5 (not shown), each group is shunted by a single controlled rectifier so as to permit inversion to enable a motor to regenerate. In addition to voltage control by determining which of the series-connected groups are to be operative, a fine control may be achieved by adjustment of phase angle. |
