High voltage bushing and high voltage device comprising such bushing
View Patent ↗A high voltage bushing for a high voltage device containing insulating liquid includes a voltage grading shield, improving performance and facilitating manufacturing.
1. A high voltage bushing for a high voltage device containing insulating liquid, the high voltage bushing comprising:
a hollow insulator housing comprising a first side insulator arranged to be provided outside of the high voltage device and a second side insulator arranged to be submerged in the insulating liquid of the high voltage device,
a high voltage conductor provided in the hollow insulator housing;
a grounded voltage grading shield provided between the high voltage conductor and the first side insulator and the second side insulator; and
a flange arranged to electrically connect the housing of the bushing to ground.
2. The high voltage bushing according to claim 1 , wherein the voltage grading shield comprises a concentric grounded tube.
3. The high voltage bushing according to claim 1 , wherein the voltage grading shield comprises a conductive material.
4. The high voltage bushing according to claim 3 , wherein the conductive material comprises aluminum.
5. The high voltage bushing according to claim 1 , further comprising:
an insulating gas inside the hollow insulator housing and surrounding the voltage grading shield.
6. The high voltage bushing according to claim 5 , wherein a space inside of the first side insulator and a space inside of the second side insulator are in communication with each other.
7. The high voltage bushing according to claim 5 , wherein the insulating gas comprises sulfur hexafluoride or molecular nitrogen.
8. The high voltage bushing according to claim 1 , further comprising:
a layer of dielectric material having a relatively low resistivity provided on the inner surface of the second side insulator.
9. The high voltage bushing according to claim 8 , wherein the layer of dielectric material comprises any of silicon rubber, composite material or varnish.
10. The high voltage bushing according to claim 1 , wherein the second side insulator has essentially a frusto-conical shape.
11. The high voltage bushing according to claim 1 , wherein the second side insulator comprises an insulating material.
12. The high voltage bushing according to claim 11 , wherein the insulating material comprises a composite material or porcelain.
13. The high voltage bushing according to claim 1 , wherein the first side insulator is arranged to be surrounded by any of the following: air, oil, and gas.
14. An electrical device, comprising:
a high voltage device; and
at least one bushing, each of the at least one bushing comprising:
a hollow insulator housing comprising a first side insulator arranged to be provided outside of the transformer and a second side insulator arranged to be submerged in the insulating liquid of the transformer,
a high voltage conductor provided in the hollow insulator housing;
a grounded voltage grading shield provided between the high voltage conductor and the first side insulator and the second side insulator; and
a flange arranged to electrically connect the housing of the bushing to ground.
15. The electrical device according to claim 14 , wherein the high voltage device comprises one of a transformer, a reactor or a breaker.