| 摘要 |
PURPOSE:To operate an AC motor not only in an ultralow speed but in a wide speed range by connecting inverters to stator and rotor windings to supply AC powers thereto. CONSTITUTION:Inverters 3, 4 each having a variable voltage and a variable frequency are respectively connected through slip rings 2 to a rotor winding and directly to a stator winding. Current detection signals Sr, Ss corresponding to detected currents Ir, Is are output to an output voltage regulator 5. The regulator 5 so regulates the output voltages of the inverters 3, 4 that the currents Is, Ir become minimum. Thus, the currents Is, Ir are minimized to suppress the heat generation of a motor 1, thereby reducing its size and operating efficiency. |
