US3728611A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tap changer
Assignee: ABB Norden Holding AB
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Filing: 1971-12-23
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Granted: 1973-04-17
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Expires: 1991-12-23
Abstract
Abstract A tap changer for switching the load current of a transformer from a first winding output to a second winding output includes two pairs of anti-parallel connected semi-conductor rectifiers with a control device for each pair. A switch arrangement is provided for connecting each of the pairs between any of the outputs and a load current connection. The device includes a control arrangement for controlling and performing the switch between the outputs, which includes a device for transmitting the load current from the rectifier pair connected to one winding output to the pair connected to an adjacent winding output. This transfer is carried out partly by natural commutation except when there is a decrease in the turns of the winding and at the same time a resistive load and partly by means of switching when the load current passes through zero upon a decrease in the turns of the winding and at the same time a resistive load.
Inventors
- 👤 S Elvin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:16
CPC Classifications
H; H01; H01H; H01H9/00; H01H9/0005; H01F; H01F29/00; H01F29/02; H01F29/04; H02; H02P; H02P13/00; H02P13/06; H01H9/54; H01H9/548
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
352 words
Tap changer for switching the load current (i1) of a transformer (12) from a first winding output (113) to a second winding output (112, 114), comprising a first and second pair of anti-parallel-connected semiconductor rectifiers (31,32 and 33,34), a control device (14,15) for each pair (31,32 and 33,34), means for connecting each of said pairs (31,32 and 33,34) between any of said winding outputs (112,113,114) and a connection for the load current (i1), said tap changer comprising controlling means (45,46) to control and perform the switching from said first winding output (113) to said second winding output (112,114) including means to transfer the load current (i1) from the rectifier pair (31,32 (33,34) ) connected to the first winding output (113) to rectifier pair (33,34 (31,32) ) connected to the second winding output (112, 114) partly by means of natural commutation except when there is a decrease in the turns of the winding and at the same time a resistive load (7) and partly by means of switching when the load current (i1) passes through zero upon a decrease in the turns of the winding and at the same time a resistive load (7), said tap changer including sensing means (50,60) to sense current and voltage in each pair of anti-parallel-connected semiconductor rectifiers (31, 32 and 33,34), an auxiliary circuit comprising a resistor (13) and an additional pair of anti-parallel-connected semiconductor rectifiers (35,36) in series with said resistor (13) parallelconnected with one of said pairs of semiconductor rectifiers (31,32 or 33,34), a control device (16) connected to the additional pair of rectifiers (35,36) forming part of the auxiliary circuit, a control means (47) including means operable upon switching from the rectifier pair (31,32 (33,34) ) not connected to the load current (i1) to the other rectifier pair (33,34 (31,32) ) to ignite the rectifier (35 or 36) in the additional rectifier pair (35,36) which has the same conducting direction as the rectifier (31 or 33) (32 or 34) in the rectifier pair (31, 32 (33,34) ) to which the auxiliary circuit is parallel-connected, which is arranged to take over the load current (i1).
Claim 2
Dependent Claim
352 words
Tap changer for switching the load current (i1) of a transformer (12) from a first winding output (113) to a second winding output (112, 114), comprising a first and second pair of anti-parallel-connected semiconductor rectifiers (31,32 and 33,34), a control device (14,15) for each pair (31,32 and 33,34), means for connecting each of said pairs (31,32 and 33,34) between any of said winding outputs (112,113,114) and a connection for the load current (i1), said tap changer comprising controlling means (45,46) to control and perform the switching from said first winding output (113) to said second winding output (112,114) including means to transfer the load current (i1) from the rectifier pair (31,32 (33,34) ) connected to the first winding output (113) to rectifier pair (33,34 (31,32) ) connected to the second winding output (112, 114) partly by means of natural commutation except when there is a decrease in the turns of the winding and at the same time a resistive load (7) and partly by means of switching when the load current (i1) passes through zero upon a decrease in the turns of the winding and at the same time a resistive load (7), said tap changer including sensing means (50,60) to sense current and voltage in each pair of anti-parallel-connected semiconductor rectifiers (31, 32 and 33,34), an auxiliary circuit comprising a resistor (13) and an additional pair of anti-parallel-connected semiconductor rectifiers (35,36) in series with said resistor (13) parallelconnected with one of said pairs of semiconductor rectifiers (31,32 or 33,34), a control device (16) connected to the additional pair of rectifiers (35,36) forming part of the auxiliary circuit, a control means (47) including means operable upon switching from the rectifier pair (31,32 (33,34) ) not connected to the load current (i1) to the other rectifier pair (33,34 (31,32) ) to ignite the rectifier (35 or 36) in the additional rectifier pair (35,36) which has the same conducting direction as the rectifier (31 or 33) (32 or 34) in the rectifier pair (31, 32 (33,34) ) to which the auxiliary circuit is parallel-connected, which is arranged to take over the load current (i1).
References Cited (Backward Citations)
US3437913A
Cited
US3619765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-16 | 1976-10-16 | 1977-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-16 | 1980-10-16 | 1981-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-16 | 1984-10-16 | 1985-04-17 | $7700.00 | Window Closed / Lapsed |