US4513346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Means to improve the dielectric performance of an insulative conduit with a flow of liquid dielectric coolant therein
Assignee: CGEE ALSTHOM NORTH AMERICA Inc
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Filing: 1983-04-27
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Granted: 1985-04-23
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Expires: 2003-04-27
Abstract
Abstract In high voltage electrical equipment, improvement in the dielectric performance of an insulative conduit having a flow of liquid dielectric coolant therein is effected by providing a suitably selected low conductance path in contact with the dielectric coolant.
Inventors
- 👤 John C. Devins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 07:29
CPC Classifications
H; H10; H10W; H10W90/00; H05; H05F; H05F3/00; H10W40/00; H10W40/40; H10W40/47
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
99 words
An apparatus to improve the dielectric performance of an insulative conduit containing a flowing liquid dielectric coolant therein, wherein a high voltage is impressed between two conductors which are spaced along the length of said insulative conduit, which conductors are in contact with said liquid dielectric coolant, said apparatus comprising: a low conductance path connected between said two spaced conductors and in contact with said liquid dielectric coolant, said low conductance path having a minimum conductance in excess of about the conductance value corresponding to a resistance per unit length of said low conductance path of 5×10 8 ohms/cm.
Claim 2
Independent Claim
99 words
An apparatus to improve the dielectric performance of an insulative conduit containing a flowing liquid dielectric coolant therein, wherein a high voltage is impressed between two conductors which are spaced along the length of said insulative conduit, which conductors are in contact with said liquid dielectric coolant, said apparatus comprising: a low conductance path connected between said two spaced conductors and in contact with said liquid dielectric coolant, said low conductance path having a minimum conductance in excess of about the conductance value corresponding to a resistance per unit length of said low conductance path of 5×10 8 ohms/cm.
Claim 3
Dependent Claim
25 words
The invention of claim 1 wherein said low conductance path has a conductance sufficiently low for limiting resistance heating therein to below about 100 watts.
Claim 4
Dependent Claim
29 words
The invention of claim 1 wherein said low conductance path has a conductance sufficiently low for limiting resistance heating therein to the range between about 5 and 10 watts.
Claim 5
Dependent Claim
21 words
The invention of claim 1 wherein said low conductance path comprises a conductive coating on the interior of said insulative conduit.
Claim 6
Dependent Claim
11 words
The invention of claim 4 wherein said conductive coating comprises graphite.
Claim 7
Dependent Claim
17 words
The invention of claim 1 wherein said low conductance path comprises a rod having a semiconducting portion.
Claim 8
Dependent Claim
13 words
The invention of claim 6 wherein said semiconducting portion comprises a semiconducting glaze.
Claim 9
Dependent Claim
14 words
The invention of claim 6 wherein said semiconducting portion of said rod comprises silicon.
Claim 10
Dependent Claim
12 words
The invention of claim 6 wherein said rod comprises a porcelain substrate.
Claim 11
Dependent Claim
16 words
The invention of claim 1 wherein said low conductance path comprises a plurality of serially-connected resistors.
Claim 12
Dependent Claim
12 words
The invention of claim 10 wherein said serially-connected resistors comprise wire-wound resistors.
Claim 13
Dependent Claim
17 words
The invention of claim 10 further comprising metallic fins disposed on at least one of said resistors.
Claim 14
Dependent Claim
26 words
The invention of claim 1 wherein said low conductance path comprises a conductive filler embedded in the interior wall of the material forming said insulative conduit.
Claim 15
Dependent Claim
26 words
The invention of claim 13 wherein said conductive filler comprises one of the group consisting of carbon, copper oxide, tin oxide, vanadium oxide, and silver oxide.
Claim 16
Dependent Claim
14 words
The invention of claim 1 wherein said liquid dielectric coolant comprises Freon 113 coolant.
Claim 17
Dependent Claim
24 words
The invention of claim 15 wherein said Freon coolant comprises one of the group consisting of Freon 113 coolant and Freon 113 TF coolant.
Claim 18
Dependent Claim
13 words
The invention of claim 1 or 2 wherein said insulative conduit comprises glass-epoxy.
Claim 19
Dependent Claim
18 words
The invention of claims 1 or 3 wherein said insulative conduit comprises a copolymer of polytetrafluoroethylene and polypropylene.
Claim 20
Dependent Claim
29 words
The invention of claim 1 wherein the voltage gradient between said two conductors which is due to said high voltage is in excess of about 10 volts per mil.
Claim 21
Dependent Claim
14 words
The invention of claim 1 wherein said electrical equipment comprises a thyristor converter bridge.
Claim 22
Independent Claim
91 words
A method for improved insulation of spaced apart electrical conductors operating at a high potential difference which are connected by an insulative fluid conduit carrying a flowing dielectric coolant, said coolnt being in contact with said electrical conductors, said method comprising: providing a low conductance path between said two spaced apart conductors and in contact with said liquid dielectric coolant, said low conductance path having a minimum conductance in excess of about the conductance value corresponding to a resistance per unit length of said low conductance path of 5×10 8 ohms/cm.
Claim 23
Independent Claim
91 words
A method for improved insulation of spaced apart electrical conductors operating at a high potential difference which are connected by an insulative fluid conduit carrying a flowing dielectric coolant, said coolnt being in contact with said electrical conductors, said method comprising: providing a low conductance path between said two spaced apart conductors and in contact with said liquid dielectric coolant, said low conductance path having a minimum conductance in excess of about the conductance value corresponding to a resistance per unit length of said low conductance path of 5×10 8 ohms/cm.
Claim 24
Independent Claim
126 words
An apparatus to improve the dielectric performance of an insulative conduit containing a flowing liquid dielectric coolant therein, wherein a high voltage is impressed between two conductors which are spaced along the length of said insulative conduit, which conductors are in contact with said liquid dielectric coolant, said apparatus comprising: a low conductance path connected between said two spaced conductors and in contact with said liquid dielectric coolant, said low conductance path haing a minimum conductance in excess of about the conductance value corresponding to a resistance per unit length of said low conductance path of 5×10 8 ohms/cm, said low conductance path also having a maximum conductance value corresponding to a resistance per unit length of said low conductance path of about 2×10 7 ohms/cm.
Claim 25
Independent Claim
126 words
An apparatus to improve the dielectric performance of an insulative conduit containing a flowing liquid dielectric coolant therein, wherein a high voltage is impressed between two conductors which are spaced along the length of said insulative conduit, which conductors are in contact with said liquid dielectric coolant, said apparatus comprising: a low conductance path connected between said two spaced conductors and in contact with said liquid dielectric coolant, said low conductance path haing a minimum conductance in excess of about the conductance value corresponding to a resistance per unit length of said low conductance path of 5×10 8 ohms/cm, said low conductance path also having a maximum conductance value corresponding to a resistance per unit length of said low conductance path of about 2×10 7 ohms/cm.
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) | 1988-04-22 | 1988-10-22 | 1989-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-22 | 1992-10-22 | 1993-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-22 | 1996-10-22 | 1997-04-23 | $7700.00 | Window Closed / Lapsed |