US3824446A
Expired / Lapsed
US
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Controlled rectifier
Assignee: Licentia Patent Verwaltungs GmbH
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Filing: 1973-02-22
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Granted: 1974-07-16
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Expires: 1993-02-22
Abstract
Abstract A rectifier circuit, for alternating current, has a plurality of controlled rectifiers and a separate quenching device for each of the controlled rectifiers. Each quenching device is connected in parallel with its associated controlled rectifier and includes a quenching thyristor and a quenching capacitor connected in series. A supplemental capacitor is connected in parallel with each of the quenching capacitors. A coupling diode is in the path connecting the supplemental capacitor with the quenching capacitor. This coupling diode and the supplemental capacitor are arranged so that the supplemental capacitor can only be charged during the period when the polarity of the quenching capacitor is changed, which occurs when the quenching capacitor is being recharged in the reverse direction after quenching of the associated controlled rectifier. The supplemental capacitor is coupled to a load which is attached to the D.C. output terminals of the rectifier. A discharge device enables the supplemental capacitor to be discharged through the load.
Inventors
- 👤 J Forster
- 👤 K Bezold
- 👤 G Vitt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:47
CPC Classifications
H; H02; H02M; H02M7/00; H02M7/02; H02M7/04; H02M7/12; H02M7/125; H02M1/00; H02M1/06; H02M7/06; H02M7/10
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
166 words
In a rectifier circuit for alternating current having a plurality of controlled rectifiers and a separate associated quenching means for each of the controlled rectifiers, each of the quenching means including a series circuit of a quenching capacitor and a control quenching thyristor with the series circuit being connected in parallel with the associated controlled rectifier, and charging means for charging the quenching capacitor to a first polarity, the improvement comprising: a supplemental capacitor connected in parallel with each of said quenching capacitors; a first coupling diode in the path connecting said supplemental capacitor and the associated said quenching capacitor; said supplemental capacitor and said first coupling diode being arranged so that said supplemental capacitor is chargeable only during the period of change of polarity of the charge of the associated said quenching capacitor; a load connected to the D.C. output terminals of said rectifier circuit; and discharge means connecting said supplemental capacitor to said load for causing discharge of said supplemental capacitor through said load.
Claim 2
Dependent Claim
166 words
In a rectifier circuit for alternating current having a plurality of controlled rectifiers and a separate associated quenching means for each of the controlled rectifiers, each of the quenching means including a series circuit of a quenching capacitor and a control quenching thyristor with the series circuit being connected in parallel with the associated controlled rectifier, and charging means for charging the quenching capacitor to a first polarity, the improvement comprising: a supplemental capacitor connected in parallel with each of said quenching capacitors; a first coupling diode in the path connecting said supplemental capacitor and the associated said quenching capacitor; said supplemental capacitor and said first coupling diode being arranged so that said supplemental capacitor is chargeable only during the period of change of polarity of the charge of the associated said quenching capacitor; a load connected to the D.C. output terminals of said rectifier circuit; and discharge means connecting said supplemental capacitor to said load for causing discharge of said supplemental capacitor through said load.
Claim 3
Dependent Claim
88 words
A controlled rectifier circuit as defined in claim 1 wherein said rectifier circuit includes a single phase bridge circuit having a separate one of said controlled rectifiers in each of two branches thereof which are directly connected in series between the direct current output terminals of said bridge; and wherein two of said supplemental capacitors are provided, said two supplemental capacitors being connected in series, with each of said supplemental capacitors being connected in parallel with a separate one of said quenching capacitors associated with said controlled rectifiers.
Claim 4
Dependent Claim
61 words
A controlled rectifier circuit is defined in claim 2 further comprising a pair of diodes each of which is connected in parallel with a separate one of said supplemental capacitors with a polarity such that only voltage with a polarity opposite to the voltage across the associated quenching capacitor prior to quenching can be provided across the associated said supplemental capacitor.
Claim 5
Dependent Claim
75 words
A controlled rectifier circuit as defined in claim 1 wherein said rectifier circuit includes a single phase bridge circuit having a separate one of said controlled rectifiers in each of two branches thereof which are directly connected in series between the direct current output terminals of said bridge; and wherein one said supplemental capacitor is provided, said one supplemental capacitor being connected in parallel with both of said quenching capacitors associated with said controlled rectifiers.
Claim 6
Dependent Claim
99 words
A controlled rectifier circuit as defined in claim 4 further comprising: two serially connected diodes connected in parallel with said supplemental capacitor and having a polarity such that only a voltage with a polarity opposite to the polarity of the voltage in said quenching capacitors prior to quenching can be produced in said supplemental capacitor, the common point of connection of said two serially connected diodes being connected with said associated quenching capacitors in such a manner that said supplemental capacitor can be charged only during the period of change of polarity of the voltage in said quenching capacitors.
Claim 7
Dependent Claim
84 words
A controlled rectifier cirCuit as defined in claim 5 further comprising: an input transformer having its secondary winding connected between the input terminals of said bridge, each of said quenching thyristors being connected to one of said input terminals of said bridge circuit, two second coupling diodes, each of said second coupling diodes connecting said point of connection of said serially connected diodes with a respective one of the points of connection between each of said quenching capacitors and its associated said quenching thyristors.
Claim 8
Dependent Claim
65 words
A controlled rectifier circuit as defined in claim 5 further comprising: an input transformer having its secondary winding connected between the input terminals of said bridge circuit, each of said quenching capacitors being connected to one of said terminals of said bridge circuit, and said point of connection of said serially connected diodes also being connected with said one input terminal of said bridge circuit.
Claim 9
Dependent Claim
56 words
A controlled rectifier circuit as defined in claim 7 wherein each of said controlled rectifiers is connected with said one input terminal of said bridge circuit via one of said serially connected diodes connected in parallel with said supplemental capacitor so that said supplemental capacitor is arranged to be discharged through said load twice per period.
Claim 10
Dependent Claim
26 words
A controlled rectifier circuit as defined in claim 1 wherein said supplemental capacitor has a capacitance value greater than that of the associated said quenching capacitor.
Claim 11
Dependent Claim
71 words
A controlled rectifier circuit as defined in claim 9 wherein said quenching capacitors are designed according to a protection period equation (C i. ts/V1) so that the protection period ts required for said controlled rectifiers is assured and said supplemental capacitor is designed so as to be capable of absorbing the energy stored in any inductances of the alternating current circuit at the moment of quenching without producing unduly high voltages.
Claim 12
Dependent Claim
18 words
A controlled rectifier circuit as defined in claim 10 wherein said supplemental capacitor is a direct voltage capacitor.
Claim 13
Dependent Claim
76 words
A controlled rectifier circuit as defined in claim 1 wherein said discharge means includes first and second auxiliary thyristors, said first auxiliary thyristor connecting the terminal of said load connected to the positive output terminal of said rectifier circuit to the positive terminal of said supplemental capacitor, and said second auxiliary thyristor connecting the terminal of said load connected to the negative output terminal of said rectifier circuit to the negative terminal of said supplemental capacitor.
Claim 14
Dependent Claim
74 words
A controlled rectifier circuit as defined in claim 1 wherein said discharge means is a resistor connected in parallel with said supplemental capacitor, and means conductively connecting the terminal of said load connected to the positive output terminal of the rectifier circuit to the positive terminal of said supplemental capacitor and the terminal of said load connected to the negative output terminal of the rectifier circuit to the negative terminal of the supplemental capacitor.
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) | 1977-07-15 | 1978-01-14 | 1978-07-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-15 | 1982-01-14 | 1982-07-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-15 | 1986-01-14 | 1986-07-16 | $7700.00 | Window Closed / Lapsed |