AC ELEVATOR CONTROL CIRCUIT

摘要

The primary voltage supplied to the induction motor is controlled to control the motoring torque in the acceleration mode and in the rated-speed runing mode, while, in the deceleration mode, a power converter unit (PC) suipplies AC power of low frequency to the induction motor to apply regenerative braking. A full wave bridge circuit including thyristors is connected at its AC terminals to the 3-phase power source. The connections between the thyristors are suitably switched over to serve both the control of the motoring torque and the control of the braking torque.