| 摘要 |
1,056,359. Converting; control of A.C. motors. ALLMANNA SVENSKA ELEKTRISKA A.B. Nov. 4, 1963 [Nov. 14, 1962], No. 43388/63. Headings H2F and H2J. An A.C. motor is supplied by a converter providing a variable frequency output to give variable speed, and control for the converter is derived from a pair of reluctance type A.C. generator devices having rotating parts driven by the motor shaft. As shown, a rotating part 23 comprises a magnetic semi-cylinder 24 and a non-magnetic semi-cylinder 25. Two magnetic cores 41, 42 for each phase are disposed about the part 23, one above and one below, each bearing a winding fed from a high frequency generator 321 or 322 and connected with oppositely directed rectifiers 211, 221, so that according as whether the magnetic half 24 completes the upper or lower magnetic circuits so a voltage E 2 is derived in one sense or the other. An exactly similar device is associated with the other rotating part 13, but the magnetic and non-magnetic semi-cylinders are displaced by 90 degrees on the shaft. A voltage E 1 is derived from this device, the voltages E 1 , E 2 being alternating voltages having the frequency of the rotor and being 90 degrees phase displaced. These two are added to give a voltage E 5 which is used to control the inverter, similar voltages being derived for the other phases of the three phase supply. To increase speed the phase of the voltage E 5 is advanced, this being effected by varying the magnitude of E 1 relative to E 2 by control of the high frequency generators. |
