Flux corrective control apparatus for motor drives
AssigneeWestinghouse Electric Corp.
InventorWalter R. Harris
Life of this patent
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Abstract
A direct current motor control apparatus includes corrective circuit for eliminating the influence of non-linearities on speed regulation as a result of load variations. A summer circuit at the input of the speed regulator algebraically combines signals representing respectively the armature current and voltage to derive a signal representing the counter-electromotive force of the motor. The latter signal is compared in the summer circuit with a signal representing motor speed for supplying a corrective error signal to the speed regulator, thereby to keep the air gap flux constant and provide a speed-load characteristic which is linear in relation to the armature current drop.
Claims1
In a direct-current motor control apparatus including a field winding and a field current regulator responsive to an armature current signal and a field reference signal for establishing a drooping speed-load characteristic, the combination of:
- means for deriving a motor armature voltage representative signal;
- means for deriving a motor armature current representative signal;
- means for subtracting said armature voltage signal from said armature current signal to derive a speed correction signal;
- means for summing said reference signal with said speed correction signal operative on said regulator to compensate for non-linear field variations as a function of load, thereby to establish a linear speed-load characteristic for said motor through said field current regulator.
Dependencies are inferred from the claim text.