| 摘要 |
PURPOSE:To obtain a brake torque in low speed range by employing regenerative braking and counterelectromotive force control by field inversion. CONSTITUTION:A speed control amplifier 2 outputs a deviation signal between the speed command of a speed setter 1 and the speed feedback of a rotating speed detecting tachometer generator 8, and a motor control amplifier 3 controls a one-side full-arm thyristor converter 4 in response to the deviation signal. When the speed is lowered, the speed feedback becomes larger than the set value via a speed command. Then, a signal is outputted from a switching instruction unit 26. Thus, normal/reverse switching contactors 14a, 14b are switched to reverse side. A relay 16 is opened, a relay 20 is closed, and the deviation between the counterelectromotive force set value of a counterelectromotive force setter 17 and the counterelectromotive force feedback of a voltage sensor 18 is supplied to a field regulating thyristor converter 4. |
