US4173779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single-pole commutation circuit
Assignee: Westinghouse Electric Corp
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Filing: 1978-12-08
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Granted: 1979-11-06
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Expires: 1998-12-08
Abstract
Abstract A commutation circuit for thyristors alternately turned ON by pulse width modulation (PWM) for the generation of a fundamental sine wave is characterized by two separate primary windings associated with respective positive and negative thyristors with a common secondary winding at the output, and two commutating networks for the respective poles, each including an auxiliary thyristor for fixed-commutation and the resonant combination of a capacitor and an inductor. The thyristors, the commutating networks, the DC source, and the output transformer have a symmetrical disposition as well as symmetrical commutation steps.
Inventors
- 👤 Alberto Abbondanti
- 👤 Andress Kernick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:22
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/42; H02M7/44; H02M7/48; H02M7/505; H02M7/515; H02M7/5152; H02M3/00; H02M3/22; H02M3/24; H02M3/28; H02M3/305; H02M3/315; H02M7/523
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
246 words
In a commutation circuit for alternately commutating a first and a second main thyristor connected in parallel across the poles of a direct current power source, the combination of: a positive pole network for commutating said first thyristor in relation to the positive pole of said source; a negative pole network for commutating said second thyristor in relation to the negative pole of said source; said first thyristor when conductive establishing a first current path across said DC source, said first current path including in series a first inductor and a first primary winding; said second thyristor when conductive establishing a second current path across said DC source, said second current path including in series a second inductor path and a second primary winding; said first and second primary windings being driven in opposite directions; a common secondary winding responsive to said first and second primary windings for outputting AC power converted by said first and second thyristors from said DC source; said positive pole commutating network including a first capacitor associated with said positive pole, a first auxiliary thyristor, said first inductor and a first diode connected in antiparallel relation to said first thyristor; said negative pole commutating network including a second capacitor associated with said negative pole, a second auxiliary thyristor, said second inductor and a second diode connected in antiparallel relation to said second thyristor; with said first and second capacitors and said first and second auxiliary thyristors having a common junction point.
Claim 2
Dependent Claim
246 words
In a commutation circuit for alternately commutating a first and a second main thyristor connected in parallel across the poles of a direct current power source, the combination of: a positive pole network for commutating said first thyristor in relation to the positive pole of said source; a negative pole network for commutating said second thyristor in relation to the negative pole of said source; said first thyristor when conductive establishing a first current path across said DC source, said first current path including in series a first inductor and a first primary winding; said second thyristor when conductive establishing a second current path across said DC source, said second current path including in series a second inductor path and a second primary winding; said first and second primary windings being driven in opposite directions; a common secondary winding responsive to said first and second primary windings for outputting AC power converted by said first and second thyristors from said DC source; said positive pole commutating network including a first capacitor associated with said positive pole, a first auxiliary thyristor, said first inductor and a first diode connected in antiparallel relation to said first thyristor; said negative pole commutating network including a second capacitor associated with said negative pole, a second auxiliary thyristor, said second inductor and a second diode connected in antiparallel relation to said second thyristor; with said first and second capacitors and said first and second auxiliary thyristors having a common junction point.
Claim 3
Dependent Claim
45 words
The commutation circuit of claim 1 with said first and second inductors being combined into a common inductor connected between on the one hand said first and second auxiliary thyristors and on the other hand said first and second capacitors, at said common junction point.
Claim 4
Dependent Claim
29 words
The commutation circuit of claim 1 with second and third auxiliary windings at substantially unity coupling to each other, connected in the respective said first and second current paths.
Claim 5
Dependent Claim
18 words
The commutation circuit of claim 1 with filtering means associated with said first and second primary windings, respectively.
Claim 6
Dependent Claim
15 words
The commutation circuit of claim 1 with filtering means associated with said common secondary winding.
Claim 7
Dependent Claim
30 words
The commutation circuit of claim 1 with rectifier means associated with the output of said common secondary winding for outputting direct current in relation to said direct current power source.
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) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |