| 摘要 |
PURPOSE:To perform a starting method for a variable speed induction motor capable of shifting its speed in a wide range and having sufficiently large torque by starting the motor in variable frequency the primary shortcircuit and secondary excitation up to 50% speed, and accelerating the motor with the primary voltage as a low voltage with secondary excitation variable speed operation at about 50% speed. CONSTITUTION:A breaker 7 is closed to shortcircuit the primary coil 3 of an induction motor 2 through a shortcircuiting circuit 10 at from zero to 50% speed of the motor 2 to excite the secondary coil 4 by a cycloconverter 17 in variable frequency and to start to accelerate the motor. When reaching the 50% speed, the breaker 7 is opened, a breaker 6 is closed to supply a low voltage to the primary coil 3. When reaching to 100% speed, the breaker 6 is opened, a breaker 5 is closed to supply system power source voltage to the coil 3. |
