SYSTEM FOR DYNAMICALLY COOLING A HIGH VOLTAGE CABLE TERMINATION

• US 3,716,652 A
• Filed: 04/18/1972
• Issued: 02/13/1973
• Est. Priority Date: 04/18/1972
• Status: Expired due to Term

• Current Assignee: George E. Lusk, James H. Nicholas
• Original Assignee: George E. Lusk, James H. Nicholas
• Inventors: Lusk, George E., Nicholas, James H.
• Primary Examiner(s): Gilheany, Bernard A.
• Assistant Examiner(s): Grimley, A. T.
• Application Number:
  US05/245,211
• Time in Patent Office: 301 Days
• Field of Search: 174/14BH,15BH,16BH,15R,15C,20,19,21R,22R,22C,23R,DIG.10
• US Class Current: 174/15.3
• CPC Class Codes: H01B 17/005 Insulators structurally associated with built-in electrical equipment
• CPC Class Codes: H02G 15/22 Cable terminations
• CPC Class Codes: Y10S 174/10 Bushing with current transformers
• CPC Class Codes: Y10S 174/32 having means for cooling

Abstract

A dynamically cooled high voltage cable termination with a pothead, and a hollow core conductor cable, employs a circulating insulating liquid dielectric through a closed loop system having flow passages within the cable conductor core and a heat exchanger external to the pothead structure. The heat exchanger and other associated components may be disposed at the normally high voltage end of the pothead. The current carrying capacity of the cable within the pothead is thereby effectively increased, together with the energy transferring capabilities of the cable system with which it is associated, without degradation of the dielectric characteristics of the cable termination.

Claims

1. A dynamic cable termination cooling system comprising a pothead having an outer insulator, a hollow cable conductor extending along the pothead axis, and insulation disposed about said cable conductor and within said outer insulator, a tube disposed within said hollow conductor defining an annular space between the tube and said conductor, said annular space forming a first flow passage and the interior of said tube forming a second flow passage, a port in said tube communicating between said first and second flow passages at one end thereof, and means coupled to said annular space and to said tube at the other respective ends of said flow passages defining a loop for the circulation of a coolant liquid through said first and second passages, the portion of said loop within said pothead being confined substantially to the interior of said hollow cable conductor, and said means including a pump and heat transfer means for cooling saId liquid.

2. The system of claim 1 wherein said heat transfer means comprises a coiled tube coupled between said first and second flow passages, and said coiled tube is disposed at the normally high voltage end of said pothead.

3. The system of claim 2 wherein said coiled tube is in direct heat transfer relation to the ambient air.

4. The system of claim 1 wherein said pump coupled in said loop is disposed at the normally high voltage end of said pothead.

5. The system of claim 4 comprising an electric driving motor coupled to said pump, and means for deriving electrical energy from said conductor for energizing said motor.

6. The system of claim 5 wherein the pothead includes terminal means located at the normally high voltage end thereof and extending externally therefrom, said terminal means being electrically connected to said conductor, and said means for deriving electrical energy comprises a current transformer coupled to said terminal means.

7. The system of claim 6 wherein said terminal means comprises a cylindrical connector member axially disposed at the normally high voltage end of said pothead, and said current transformer includes an annular coil concentrically disposed about said connector member.

8. The system of claim 1 wherein said pothead includes a metal body portion at the normally grounded end thereof, and said first and second flow passages extend to a predetermined point along the hollow conductor within said body portion.

9. The system of claim 8 wherein further means are provided for cooling the portion of the hollow conductor within said pothead body portion located beyond said predetermined point, said further means being independent of said loop.

10. The system of claim 8 for use with an oil filled pipe cable system, said system comprising means for conducting the pipe oil through said pothead body portion.

11. The system of claim 10 wherein stress relief insulation is provided about said conductor within said body portion, and an oil baffle is disposed about said stress relief insulation and at least coextensive therewith along the axis of the pothead within said body portion

12. The system of claim 11 wherein said insulation is impregnated with an insulating liquid dielectric of the pothead, said system comprising a valve and filter coupled to a port in said baffle for communication between the pothead liquid dielectric and the pipe oil.

13. A dynamically cooled pothead for use with a hollow core cable, the cable conductor extending along the pothead axis, said pothead comprising an outer insulator, insulation disposed about said cable conductor and within said outer insulator, a tube disposed within the conductor core defining an annular space between the tube and said conductor, said annular space forming a first flow passage and the interior of said tube forming a second flow passage, a port in said tube communicating between said first and second flow passages at one end thereof, and means coupled to said annular space and to said tube at the other respective ends of said flow passages for circulating an insulating liquid dielectric through a loop including said first and second flow passages, said means including a pump and heat transfer means for cooling said liquid, said pump and heat transfer means being disposed at the normally high voltage end of the pothead and said heat transfer means being in direct heat transfer relation to the surrounding ambient.

14. The pothead of claim 13 wherein said heat transfer means comprises a coiled tube coupled between said first and second flow passages.

15. The pothead of claim 14 comprising an electric driving motor coupled to said pump and means for deriving electrical energy from said conductor for energizing said motor.

16. The pothead of claim 15 wherein in the pothead includes terminal means located at the normally high voltage end thereof and extending externally therefrom, said terminal means being electrically connected to said hollow conductor, And said means for deriving electrical energy comprises a current transformer coupled to said terminal means.

17. The pothead of claim 16 wherein said means for deriving electrical energy further comprises a control circuit for controlling the application of power to said motor in accordance with a predetermined mode of operation.

18. The pothead of claim 13 wherein said circulating means includes a filter in said loop for maintaining the dielectric qualities of said insulating liquid.