DC Motor control using motor-generator set with controlled generator field
First Claim
1. A system for controlling a d.c. drive motor subject to variable load comprising:
- a source of the d.c. current, a motor-generator set having a d.c. generator connected in series between the source of current and the drive motor such that common polarity terminals of the power source and the generator are connected together so that the generator generates a voltage in opposition to the power source, said generator having at least one field winding subject to control, and motor means rotationally coupled to the d.c. generator to drive the generator and electrically coupled to the source of d.c. power, andmeans to vary said at least one field winding whereby, when the d.c. drive motor is at rest, the field of the generator is controlled so that its generator voltage output is equal to but opposite to the voltage output of the power source, the motor generator means alternately acting as a motor to drive the generator and as a generator driven by the generator acting as a motor whereby power corresponding to the unused excess energy is fed back into the power source.
2 Assignments
0 Petitions
Accused Products
Abstract
A d.c. generator is connected in series opposed to the polarity of a d.c. power source supplying a d.c. drive motor. The generator is part of a motor-generator set, the motor of which is supplied from the power source connected to the motor. A generator field control means varies the field produced by at least one of the generator windings in order to change the effective voltage output. When the generator voltage is exactly equal to the d.c. voltage supply, no voltage is applied across the drive motor. As the field of the generator is reduced, the drive motor is supplied greater voltage until the full voltage of the d.c. power source is supplied when the generator has zero field applied. Additional voltage may be applied across the drive motor by reversing and increasing the reversed field on the generator. The drive motor may be reversed in direction from standstill by increasing the generator field so that a reverse voltage is applied across the d.c. motor.
7 Citations
17 Claims
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1. A system for controlling a d.c. drive motor subject to variable load comprising:
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a source of the d.c. current, a motor-generator set having a d.c. generator connected in series between the source of current and the drive motor such that common polarity terminals of the power source and the generator are connected together so that the generator generates a voltage in opposition to the power source, said generator having at least one field winding subject to control, and motor means rotationally coupled to the d.c. generator to drive the generator and electrically coupled to the source of d.c. power, and means to vary said at least one field winding whereby, when the d.c. drive motor is at rest, the field of the generator is controlled so that its generator voltage output is equal to but opposite to the voltage output of the power source, the motor generator means alternately acting as a motor to drive the generator and as a generator driven by the generator acting as a motor whereby power corresponding to the unused excess energy is fed back into the power source. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of controlling a d.c. drive motor subject to variable load comprising:
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connecting a d.c. generator of a motor-generator set in series opposition to a d.c. power source across the d.c. drive motor and connecting the motor of the motor-generator set to the same d.c. power source; adjusting the field of the d.c. generator until the voltage output of the generator just balances the voltage of the d.c. power source so that the drive motor is not driven, and varying the field of the generator to reduce its strength to allow the net voltage to drive the motor in a forward direction. - View Dependent Claims (15, 16, 17)
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Specification