device for continuous control or regulation of the speed and / or the torque of a three-phase asynchronous machine.

摘要

The circuit consists of two full wave three phase rectifying bridges (5) each comprising six thyristors, which are driven by a timed gating circuit. These two circuits are connected effectively in series with intervening chokes between the three phase mains supply and the asynchronous machine. A phase shifted parallel full wave three phase bridge (6) completes the motor operation, whilst a similar pair of bridges (7, 12) is capable of feeding power in the opposite direction via a transformer back to the supply. This achieves a voltage limitation at the machine under changing load conditions, and within certain limits allows smoother control of speed and torque using sequenced firing circuits.