US3668511A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self energizing tap switch for electronic tap changer
Assignee: Cooper Industries LLC
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Filing: 1971-02-16
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Granted: 1972-06-06
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Expires: 1991-02-16
Abstract
Abstract A self energizing tap switch is disclosed as being connected in circuit with the primary winding of a transformer having a plurality of tap sections connected to an electronic tap changer. The tap switch connects two portions of the primary winding together when the transformer is initially energized or after the winding has been energized when there is no shunt connection between connections or when a malfunction causes the opening of a tap connection between tap sections. The tap switch includes a pair of silicon controlled rectifiers for carrying transformer load current during alternate half cycles of the energy source connected to the terminals of the primary winding. The gating circuit for each of the silicon rectifiers includes a capacitor for creating a gate current which leads the load current in the situation where the load current leads the load voltage. When a tap section is shunted out of the primary winding by a tap connection, it is desired that the silicon controlled rectifiers do not conduct to short out the tap shunt connection and thereby effectively reinsert the tap section. To prevent such conduction, a second pair of silicon controlled rectifiers are each connected in parallel with the gate-cathode circuit of one of the first pair of silicon controlled rectifiers. The second pair of silicon rectifiers are gated when a tap shunt connection is made so that gate current to the first pair of silicon rectifiers is diverted and prevented from triggering the first pair of silicon controlled rectifiers.
Inventors
- 👤 Charles E Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:44
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/04; H02H7/055; H01; H01F; H01F29/00; H01F29/02; H01H; H01H9/00; H01H9/0005
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
112 words
In an electronic tap changer for a transformer including a secondary winding and a primary winding having a plurality of tap sections and being connected to an alternating polarity current and voltage energy source and carrying said current, a tap switch comprising: circuit means coupled to the primary winding for producing a conducting signal comprising energy from said source and having a predetermined relationship with said current; and first switch means connected in an electrical circuit between two of said tap sections and receiving said signal, said first switch means being responsive to said signal and to said current to conduct the current between said two tap sections of the primary winding.
Claim 2
Dependent Claim
112 words
In an electronic tap changer for a transformer including a secondary winding and a primary winding having a plurality of tap sections and being connected to an alternating polarity current and voltage energy source and carrying said current, a tap switch comprising: circuit means coupled to the primary winding for producing a conducting signal comprising energy from said source and having a predetermined relationship with said current; and first switch means connected in an electrical circuit between two of said tap sections and receiving said signal, said first switch means being responsive to said signal and to said current to conduct the current between said two tap sections of the primary winding.
Claim 3
Dependent Claim
26 words
The combination according to claim 1 wherein said circuit means is responsive to the voltage on one of said tap sections to produce said conducting signal.
Claim 4
Dependent Claim
61 words
The combination according to claim 2 wherein: said circuit means is producing said conducting signal at the time said current changes polarity; and said first switch means has an opposite current conducting direction for each alternate polarity of said current and is responsive to said conducting signal when the current changes polarity to conduct current in each of said opposite directions.
Claim 5
Dependent Claim
58 words
The combination according to claim 3 wherein: said conducting signal has two separate portions; and said first switch means includes first and second static switches alternately conducting said current in a different one of said opposite directions, each static switch being responsive to a different one of the two portions of the conducting signal to conduct said current.
Claim 6
Dependent Claim
70 words
The combination accordint to claim 4 wherein: said first and second static switches each have an input circuit separately connected to said circuit means and respectively receiving a different one of the two portions of the conducting signal; and further comprising shunting means connected in parallel with said input circuits for diverting said conducting signal from said input Circuits whereby conduction of said first and second static switches is prevented.
Claim 7
Dependent Claim
41 words
The combination according to claim 1 wherein: said primary winding has a load current conductive condition and a load current non-conductive condition; and said circuit means produces said conducting signal while said primary winding is in said load current non-conductive condition.
Claim 8
Dependent Claim
35 words
The combination according to claim 1 wherein said circuit means is directly connected to the primary winding and stores electrical energy from said source, said conducting signal comprising electrical energy stored by said circuit means.
Claim 9
Dependent Claim
112 words
In an electronic tap changer including a tap changing switch for a transformer having a secondary winding and a primary winding having a plurality of tap sections and being connected to an alternating polarity current and voltage energy source and carrying current from said source, a tap switch comprising: circuit means coupled to the primary winding for producing a conducting signal; first switch means responsive to the conducting signal and to said current to conduct the current between said tap sections of the primary winding; and second switch means in a current conducting circuit with said primary winding and said first switch means for selectively preventing conduction of the first switch means.
Claim 10
Dependent Claim
112 words
In an electronic tap changer including a tap changing switch for a transformer having a secondary winding and a primary winding having a plurality of tap sections and being connected to an alternating polarity current and voltage energy source and carrying current from said source, a tap switch comprising: circuit means coupled to the primary winding for producing a conducting signal; first switch means responsive to the conducting signal and to said current to conduct the current between said tap sections of the primary winding; and second switch means in a current conducting circuit with said primary winding and said first switch means for selectively preventing conduction of the first switch means.
Claim 11
Dependent Claim
30 words
The combination according to claim 8 wherein said second switch means is responsive to a predetermined voltage drop on said primary winding to prevent conduction of the first switch means.
Claim 12
Dependent Claim
79 words
The combination according to claim 8 wherein: said tap changing switch has a conductive condition in shunt with said first switch means; said first switch means has a first instantaneous voltage drop thereacross when conducting said current and a second instantaneous voltage drop opposite to the first voltage drop when said tap changing switch is in a conductive condition; and said second switch means is responsive to the second voltage drop to prevent conduction of the first switch means.
Claim 13
Dependent Claim
30 words
The combination according to claim 10 wherein said second switch means is conductive in response to said second voltage drop to divert said conducting signal from the first switch means.
Claim 14
Dependent Claim
30 words
The combination according to claim 11 wherein: said first switch means has an input circuit receiving said conducting signal; and said second switch means is connected to said input circuit.
Claim 15
Dependent Claim
122 words
The combination according to claim 12 wherein: said first switch means comprises a first pair of static switches each conductive in an opposite direction as the polarity of said current alternates and each having a first control electrode receiving a different portion of said conducting signal; and said second switch means comprises a second pair of static switches each having first and second series connected electrodes in shunt circuit with one of said first control electrodes and each having a second control electrode receiving said second voltage drop, each of said first and second electrodes of a second static switch becoming conductive when the second control electrode of the same second static switch receives a predetermined portion of the second voltage drop.
Claim 16
Dependent Claim
36 words
The combination according to claim 13 wherein said second voltage drop is an alternating polarity voltage drop and said predetermined portion is a portion of the second voltage drop having the same polarity as said current.
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) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |