Patent US3821630A successfully refreshed from Google Patents.
US3821630A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Commutation failure detection and control for scr inverters
Assignee: General Electric Co
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Filing: 1973-08-02
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Granted: 1974-06-28
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Expires: 1993-08-02
Abstract
Abstract A direct current-to-alternating current inverter employing a silicon controlled rectifier (SCR) is described in which control means is provided to promptly and automatically restore inverter operation after a commutation failure. The control means includes means for sensing the instantaneous voltage across the SCR and comparing this voltage with a threshold voltage. Whenever the SCR voltage is lower than the threshold voltage, the gating pulses to the SCR and a series connected chopper of the inverter are inhibited. When the threshold voltage is exceeded, gating pulses are passed to the SCR and the chopper, thereby providing normal inverter operation.
Inventors
- 👤 W Kornrumpf
- 👤 J Walden
- 👤 L Walker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:02
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/10; H02H7/12; H02H7/122; H02H7/1225; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/156; H02M3/158; Y; Y02; Y02B; Y02B70/00; Y02B70/10
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
An improved direct current-to-alternating current inverter comprising: an SCR; a series resonant circuit operatively connected with said SCR; a current controlling means having one terminal operatively connected to said SCR and another terminal adapted to be connected to a source of direct current; control means for providing gating signals to said SCR and said current controlling means to control the flow of current therethrough; and means foR inhibiting at least the gating signals to said current controlling means upon the occurrence of a commutation failure of said SCR, said means for inhibiting including means for sensing the instantaneous voltage across said SCR.
Claim 2
Dependent Claim
102 words
An improved direct current-to-alternating current inverter comprising: an SCR; a series resonant circuit operatively connected with said SCR; a current controlling means having one terminal operatively connected to said SCR and another terminal adapted to be connected to a source of direct current; control means for providing gating signals to said SCR and said current controlling means to control the flow of current therethrough; and means foR inhibiting at least the gating signals to said current controlling means upon the occurrence of a commutation failure of said SCR, said means for inhibiting including means for sensing the instantaneous voltage across said SCR.
Claim 3
Dependent Claim
50 words
The inverter of claim 1 wherein said means for inhibiting further includes means for comparing the instantaneous voltage across said SCR with a threshold voltage, said means for comparing providing an inhibit signal for said control means whenever the magnitude of said instantaneous voltage is less than said threshold voltage.
Claim 4
Dependent Claim
44 words
The inverter of claim 2 wherein said means for comparing comprises an operational amplifier having a first input connected to the anode of said SCR and a second input connected to the cathode of said SCR for sensing the instantaneous voltage across said SCR.
Claim 5
Dependent Claim
24 words
The inverter of claim 3 further including: a source of a threshold voltage; and means coupling said threshold voltage to said means for comparing.
Claim 6
Dependent Claim
44 words
The inverter of claim 1 wherein said series resonant circuit includes a capacitor and an inductor in series with a load and said current controlling means includes resistive means connected between said terminals for charging said capacitor after the occurrence of a commutation failure.
Claim 7
Dependent Claim
22 words
The inverter of claim 1 wherein said means for inhibiting inhibits the gating signals to said current controlling means and said SCR.
Claim 8
Independent Claim
113 words
A method of protecting a direct current-to alternating current inverter in the event of a commutation failure wherein said inverter includes a current controlling device adapted to be connected between a series resonant circuit and a source of direct current with an SCR connected in parallel with said series resonant circuit, said method comprising: sensing the instantaneous voltage across said SCR; comparing the instantaneous voltage across said SCR with a threshold voltage; inhibiting the current flow through said SCR when the instantaneous voltage across said SCR is less than said threshold voltage; and automatically restoring current flow through said SCR when the instantaneous voltage across said SCR is greater than said threshold voltage.
Claim 9
Independent Claim
113 words
A method of protecting a direct current-to alternating current inverter in the event of a commutation failure wherein said inverter includes a current controlling device adapted to be connected between a series resonant circuit and a source of direct current with an SCR connected in parallel with said series resonant circuit, said method comprising: sensing the instantaneous voltage across said SCR; comparing the instantaneous voltage across said SCR with a threshold voltage; inhibiting the current flow through said SCR when the instantaneous voltage across said SCR is less than said threshold voltage; and automatically restoring current flow through said SCR when the instantaneous voltage across said SCR is greater than said threshold voltage.
Claim 10
Dependent Claim
36 words
The method of claim 7 wherein the step of automatically restoring current flow through said SCR includes: applying a charging current to said series resonant circuit for developing therein a voltage greater than said threshold voltage.
Claim 11
Dependent Claim
35 words
The method of claim 8 wherein the step of automatically restoring current flow through said SCR further includes: generating gating signals to said SCR and said current controlling device after said threshold voltage is exceeded.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |