US3609388A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic paralleling circuit
Assignee: General Electric Co
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Filing: 1970-06-24
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Granted: 1971-09-28
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Expires: 1990-06-24
Abstract
Abstract A circuit for automatically paralleling AC generators. Upon detecting a first, small differential voltage between a main bus and the corresponding terminal of an off-line generator a first relay is actuated, applying the differential voltage to a second relay. When the differential voltage attains a second, higher value a circuit for energizing mechanical contactors is partially completed. As the differential voltage subsequently lessens, the first relay drops out, completing the energization of the circuit and the mechanical contactors. The dropout voltage of the first relay is such that the increment of time necessary for the differential voltage to fall from the first relay dropout voltage to zero is substantially the same as the time necessary for the actuation of the contactors.
Inventors
- 👤 Stuart F Hemmenway
- 👤 William H Turner Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:37
CPC Classifications
H; H02; H02J; H02J3/00; H02J3/38; H02J3/40; H02J3/42
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
225 words
A selection system for coupling a preselected alternating current generator to main lines carrying alternating current, comprising: contactor means for coupling the terminals of said generator to corresponding ones of said lines; first switch means for energizing said contactor means, said first switch means including first and second portions; means for supplying a first, variable voltage, including means for comparing the voltage of one of said generator terminals with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second voltage; second, third and fourth switch means; i. said second switch means being connected across said fist voltage supply, said second switch means being energizable at a first, lower voltage to disable said first portion of said first switch means and to connect said third switch means across said first voltage supply; ii. said third switch means being energizable at a second, higher voltage to connect said fourth switch means across said second voltage supply; iii. said fourth switch means being energizable by said second voltage supply means to enable said second portion of said first switch means; iv. said second switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said first switch means is enabled.
Claim 2
Dependent Claim
225 words
A selection system for coupling a preselected alternating current generator to main lines carrying alternating current, comprising: contactor means for coupling the terminals of said generator to corresponding ones of said lines; first switch means for energizing said contactor means, said first switch means including first and second portions; means for supplying a first, variable voltage, including means for comparing the voltage of one of said generator terminals with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second voltage; second, third and fourth switch means; i. said second switch means being connected across said fist voltage supply, said second switch means being energizable at a first, lower voltage to disable said first portion of said first switch means and to connect said third switch means across said first voltage supply; ii. said third switch means being energizable at a second, higher voltage to connect said fourth switch means across said second voltage supply; iii. said fourth switch means being energizable by said second voltage supply means to enable said second portion of said first switch means; iv. said second switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said first switch means is enabled.
Claim 3
Dependent Claim
236 words
A selection system for coupling a preselected alternating current generator to main lines carrying alternating current, comprising: contactor means for coupling the terminals of said generator to corresponding ones of said lines; gated switch means for energizing said contactor means, said gated switch means including a gating circuit for energizing said gated switch means, said gating circuit having first and second portions; means for supplying a first, variable voltage, including means for comparing the voltage of one of said generator terminals with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second, constant voltage; first, second and third switch means, i. said first switch means being connected across said first voltage supply, said first switch means being energizable at a first, lower voltage to disable said first portion of said gating circuit and to connect said second switch means across said first voltage supply; ii. said second switch means being energizable at a second, higher voltage to connect said third switch means across said second voltage supply; iii. said third switch means being energizable by said second voltage supply means to enable said second portion of said gating circuit; iv. said first switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said gating circuit is enabled.
Claim 4
Dependent Claim
236 words
A selection system for coupling a preselected alternating current generator to main lines carrying alternating current, comprising: contactor means for coupling the terminals of said generator to corresponding ones of said lines; gated switch means for energizing said contactor means, said gated switch means including a gating circuit for energizing said gated switch means, said gating circuit having first and second portions; means for supplying a first, variable voltage, including means for comparing the voltage of one of said generator terminals with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second, constant voltage; first, second and third switch means, i. said first switch means being connected across said first voltage supply, said first switch means being energizable at a first, lower voltage to disable said first portion of said gating circuit and to connect said second switch means across said first voltage supply; ii. said second switch means being energizable at a second, higher voltage to connect said third switch means across said second voltage supply; iii. said third switch means being energizable by said second voltage supply means to enable said second portion of said gating circuit; iv. said first switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said gating circuit is enabled.
Claim 5
Dependent Claim
45 words
A selection system as defined in claim 2 further including: means for shunting said gated switch means upon the energization of said contactor means; and fourth switch means for decoupling said selection system from said contactor means and from said one of said generator terminals.
Claim 6
Dependent Claim
18 words
A selection system as defined in claim 2 wherein said first, second and third switch means are relays.
Claim 7
Dependent Claim
16 words
A selection system as defined in claim 4 wherein said gated switch means is an SCR.
Claim 8
Dependent Claim
232 words
A selection system for coupling one of a plurality of polyphase generators to main lines carrying polyphase current, comprising: contactor means for coupling each of the phases of said generator to corresponding ones of said lines; first switch means for energizing said contactor means, said first switch means including first and second portions; means for supplying a first, variable voltage comprising means for comparing the voltage of one of said phases of said generator with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second voltage; second, third and fourth switch means, i. said second switch means being connected across said first voltage supply means, said second switch means being energizable by a first, lower voltage to disable said first portion of said first switch means and to connect said third switch means across said first voltage supply; ii. said third switch means being energizable at a second, higher voltage to connect said fourth switch means across said second voltage supply; iii. said fourth switch means being energizable by said second voltage supply means to enable said second portion of said first switch means; iv. said second switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said first switch means is enabled.
Claim 9
Dependent Claim
232 words
A selection system for coupling one of a plurality of polyphase generators to main lines carrying polyphase current, comprising: contactor means for coupling each of the phases of said generator to corresponding ones of said lines; first switch means for energizing said contactor means, said first switch means including first and second portions; means for supplying a first, variable voltage comprising means for comparing the voltage of one of said phases of said generator with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second voltage; second, third and fourth switch means, i. said second switch means being connected across said first voltage supply means, said second switch means being energizable by a first, lower voltage to disable said first portion of said first switch means and to connect said third switch means across said first voltage supply; ii. said third switch means being energizable at a second, higher voltage to connect said fourth switch means across said second voltage supply; iii. said fourth switch means being energizable by said second voltage supply means to enable said second portion of said first switch means; iv. said second switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said first switch means is enabled.
Claim 10
Dependent Claim
243 words
A selection system for coupling one of a plurality of polyphase generators to main lines carrying polyphase current, comprising: contactor means for coupling each of the phases of said generator to corresponding ones of said lines; gated switch means for energizing said contactor means, said gated switch means including a gate circuit for energizing said gated switch means, said gating circuit having first and second portions; means for supplying a first, variable voltage comprising means for comparing the voltage of one of said phases of said generator with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second, constant voltage; first, second and third switch means, i. said first switch means being connected across said first voltage supply means, said first switch means being energizable by a first, lower voltage to disable said first portion of said gating circuit and to connect said second switch means across said first voltage supply; ii. said second switch means being energizable at a second, higher voltage to connect said third switch means across said second voltage supply; iii. said third switch means being energizable by said second voltage supply means to enable said second portion of said gating circuit; iv. said fist switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said gating circuit is enabled.
Claim 11
Dependent Claim
243 words
A selection system for coupling one of a plurality of polyphase generators to main lines carrying polyphase current, comprising: contactor means for coupling each of the phases of said generator to corresponding ones of said lines; gated switch means for energizing said contactor means, said gated switch means including a gate circuit for energizing said gated switch means, said gating circuit having first and second portions; means for supplying a first, variable voltage comprising means for comparing the voltage of one of said phases of said generator with the voltage of a corresponding one of said lines and producing a voltage output representative of the difference therebetween; means for supplying a second, constant voltage; first, second and third switch means, i. said first switch means being connected across said first voltage supply means, said first switch means being energizable by a first, lower voltage to disable said first portion of said gating circuit and to connect said second switch means across said first voltage supply; ii. said second switch means being energizable at a second, higher voltage to connect said third switch means across said second voltage supply; iii. said third switch means being energizable by said second voltage supply means to enable said second portion of said gating circuit; iv. said fist switch means becoming deenergized when said first voltage supply means subsequently provides a voltage less than said first, lower voltage whereby said first portion of said gating circuit is enabled.
Claim 12
Dependent Claim
45 words
A selection system as defined in claim 7 further including: means for shunting said gated switch means upon the energization of said contactor means; and fourth switch means for decoupling said selection system from said contactor means and from said one of said generator phases.
Claim 13
Dependent Claim
18 words
A selection system as defined in claim 7 wherein said first, second and third switch means are relays.
Claim 14
Dependent Claim
16 words
A selection system as defined in claim 9 wherein said gated switch means is an SCR.
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) | 1974-09-27 | 1975-03-29 | 1975-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-27 | 1979-03-29 | 1979-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-27 | 1983-03-29 | 1983-09-28 | $7700.00 | Window Closed / Lapsed |