Microprocessor-based control of steel rolling mill digital DC drives

Algorithms are presented for the digital control of double-loop DC machine drives used for applications where severe constraints on motor speed and position render conventional constant-torque or power control inadequate, such as in steel rolling mill drives. It is shown that the heavy current demand associated with maximal acceleration control can be reduced by using a form of proportional control where, in addition to the conventional inner-loop current feedback, a distance feedback term sets the high limiting value of the speed feedback signal, thus reducing the motor armature current