| 摘要 |
PURPOSE:To increase the starting torque of a motor by connecting an anti- parallel connecting circuit of thyristors to an armature coil and triggering a thyristor with a signal synchronized with the rotating speed at the starting time. CONSTITUTION:The armature coil 1 of a 3-phase permanent magnet synchronous motor 3 is connected through 3 sets of anti-parallel connection thyristors 3 to a 3-phase power source 6. A thyristor 5 is triggered with a signal synchronized with the rotating speed from a rotary position detector 4 coupled directly with a rotor at the starting time. When the motor 3 is accelerated to the prescribed speed, the thyristor 5 is triggered with a signal synchronized with a power source voltage or a DC signal. In this manner, large starting torque can be obtained, and the starting current can be reduced. |
