Patent US3410772A successfully refreshed from Google Patents.
Patent US3710230A successfully refreshed from Google Patents.
US3710230A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Commutation circuit for power inverters
Assignee: Gates LearJet Corp
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Filing: 1971-08-13
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Granted: 1973-01-09
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Expires: 1991-08-13
Abstract
Abstract Circuit provides positive cut-off of a silicon controlled rectifier from its firing state, in rapid response to a logic pulse or signal. An individual commutation circuit is utilized for each power SCR or leg of an inverter system. Inexpensive, with relatively few electrical components for each such circuit. Simple in its operation, has substantially no internal or trapped energy losses. Commutation cut-off periods or hold-off times of the order of 15 microseconds are readily attained. A single commutating condenser is used for a pair or opposed power SCRS. An inductor is arranged in series with both the power and the commutating SCR of each inverter leg, to the D.C. bus, affording substantially lower dV/dt and dI/dt impact thereon. In essence, a rapid yet ''''soft'''' commutation function is provided herein, whereby commercially available SCRS can be used for most power systems, over longer life periods. The circuit is adaptable for commutating SCRS in wide range of applications.
Inventors
- 👤 Nard D Ve
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:09
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/5152; H02M7/5155
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
222 words
A polyphase inverter system to operate in the range between and including a no-load condition through an overload condition at a predetermined output frequency comprising: a plurality of power phase circuits connected to a common direct current source; a power control rectifier in each phase circuit; circuit means for selectively commutating each said controlled rectifier and turn in OFF rapidly to thereby end its firing period in response to a control signal, said circuit means comprising an individual commutating inductor connected in series between a main electrode of each said controlled rectifier and directly from the direct current source, the other main electrode of each controlled rectifier connecting to its output phase terminal of the system, a commutation controlled rectifier in each individual circuit with each said power controlled rectifier, and a commutation capacitor for each power phase circuit the main electrodes of each commutation controlled rectifier and its associated capacitor being in series connection and in turn connected directly across the main electrodes of its respective power controlled rectifier; and means for selectively impressing gating pulses to each said commutation controlled rectifier to fire it and thereby directly discharge its associated capacitor to in turn electrically interact with the said inductor individually connected to the corresponding power controlled rectifier to effect a requisite hold-off period thereon and end its firing cycle.
Claim 2
Dependent Claim
222 words
A polyphase inverter system to operate in the range between and including a no-load condition through an overload condition at a predetermined output frequency comprising: a plurality of power phase circuits connected to a common direct current source; a power control rectifier in each phase circuit; circuit means for selectively commutating each said controlled rectifier and turn in OFF rapidly to thereby end its firing period in response to a control signal, said circuit means comprising an individual commutating inductor connected in series between a main electrode of each said controlled rectifier and directly from the direct current source, the other main electrode of each controlled rectifier connecting to its output phase terminal of the system, a commutation controlled rectifier in each individual circuit with each said power controlled rectifier, and a commutation capacitor for each power phase circuit the main electrodes of each commutation controlled rectifier and its associated capacitor being in series connection and in turn connected directly across the main electrodes of its respective power controlled rectifier; and means for selectively impressing gating pulses to each said commutation controlled rectifier to fire it and thereby directly discharge its associated capacitor to in turn electrically interact with the said inductor individually connected to the corresponding power controlled rectifier to effect a requisite hold-off period thereon and end its firing cycle.
Claim 3
Dependent Claim
54 words
A polyphase inverter system as claimed in claim 1, wherein one main electrode of each said commutation controlled rectifier is electrically connected with the individual inductor at its associated power controlled rectifier connection end, whereby said inductor softens the rate of rise of reapplied voltage to both its corresponding said power and commutating rectifiers.
Claim 4
Dependent Claim
64 words
A polyphase inverter system as claimed in claim 1, wherein the inductance and capacitance of each said associated inductor and capacitor are proportioned to have a self-resonant frequency that is substantially higher than the power system output frequency, the inverse of said frequency being equal to approximately four times the commutating hold-off period of its corresponding power controlled rectifier for positively shutting it off.
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) | 1976-01-09 | 1976-07-10 | 1977-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-09 | 1980-07-10 | 1981-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-09 | 1984-07-10 | 1985-01-09 | $7700.00 | Window Closed / Lapsed |