US4048550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flux corrective control apparatus for motor drives
Assignee: Westinghouse Electric Corp
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Filing: 1975-02-03
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Granted: 1977-09-13
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Expires: 1995-02-03
Abstract
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.
Inventors
- 👤 Walter R. Harris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:03
CPC Classifications
H; H02; H02P; H02P7/00; H02P7/06; H02P7/18; H02P7/24; H02P7/28; H02P7/282; H02P7/2825; Y; Y10; Y10S; Y10S388/00; Y10S388/90; Y10S388/902; Y10S388/907; Y10S388/917
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
112 words
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.
Claim 2
Dependent Claim
112 words
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.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |