Reversible electric drive with bidirectional back-current brake and fed by a rectifier supplied from alternating current mains, preferably for motor arc furnace regulators

摘要

A reversible electric drive with bidirectional back-current brakes fed by a rectifier supplied from a pair of A.C. power lines for a D.C. motor having two directions of rotation and two poles, comprises a control rectifier bridge for each direction of rotation, each bridge having two branches each containing a diode which is common to both bridges, a shunt resistor for each direction of rotation which is identical with a braking resistor for each other direction of rotation connected in series with the motor for each bridge, each bridge having two other branches each containing a rectifier thyristor with cathodes of each rectifier thyristor connected to a common point. The common point of each bridge is connected to one of the poles of the motor with a control thyristor connected to each common point in series with each respective shunt resistor of each bridge and connected to each other by a connecting point. The common diode is connected to the connecting point, and a braking thyristor is provided between a connecting point of each braking thyristor is provided between a connecting point of each shunt resistor and its respective control thyristor and the common points respectively.