US4080554A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable frequency static motor drive
Assignee: Westinghouse Electric Corp
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Filing: 1976-04-05
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Granted: 1978-03-21
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Expires: 1996-04-05
Abstract
Abstract A variable speed static controlled induction motor is voltage regulated under variable frequency by controlling the inverters under constant pulse width while maintaining a constant volt-hertz ratio through the feedback voltage control loop.
Inventors
- 👤 Craig J. Nordby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:57
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04; H02P27/06; H02P27/045; H02P27/048; H02P2207/00; H02P2207/01; H02P27/047
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
89 words
A variable frequency static induction motor drive comprising: a source of direct current voltage, inverter means connected between said direct current voltage source and an induction motor for supplying an alternating current voltage thereto, first control means for controlling said inverter means in relation to frequency for regulating the speed of said motor, second control means responsive to the time integral of said alternating current voltage and operative with said inverter means for establishing a predetermined level for said alternating current voltage while keeping the volt per hertz constant.
Claim 2
Dependent Claim
89 words
A variable frequency static induction motor drive comprising: a source of direct current voltage, inverter means connected between said direct current voltage source and an induction motor for supplying an alternating current voltage thereto, first control means for controlling said inverter means in relation to frequency for regulating the speed of said motor, second control means responsive to the time integral of said alternating current voltage and operative with said inverter means for establishing a predetermined level for said alternating current voltage while keeping the volt per hertz constant.
Claim 3
Dependent Claim
34 words
The motor drive of claim 1 with said second control means being operative on the conduction angle of said inventer means and establishing a constant pulse width at the output of said inverter means.
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) | 1981-03-20 | 1981-09-19 | 1982-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-20 | 1985-09-19 | 1986-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-20 | 1989-09-19 | 1990-03-21 | $7700.00 | Window Closed / Lapsed |