Electric insulation device and an electric device provided therewith
View Patent ↗An electric insulation device, including a chamber and an electrically insulating element formed by a cast polymer solidified into an elastic state inside the chamber. The electrically insulating element includes a plurality of particles of a ceramic that has a higher thermal conductivity than the one of the polymer.
1. An electric insulation device, comprising:
a chamber; and
an electrically insulating element formed by a cast polymer solidified into a gel inside said chamber, said electrically insulating element includes:
compressible particles in the form of micro-spheres having a diameter ranging from 20 μm to 500 μm distributed therein, and
a plurality of particles of a ceramic that has a higher thermal conductivity than a thermal conductivity of said polymer,
wherein a volumetric proportion of the ceramic particles is at least 5 vol. % and below 15 vol. and a volumetric portion of the compressible particles is at least 20 vol. % and below 30 vol. %;
wherein each one of said compressible particles comprises an elastic shell that sealingly encloses a gas-filled inner volume thereof and the ceramic particles form a plurality of individual agglomerates, and a mean diameter of the agglomerates is above 130 μm.
2. The electric insulation device according to claim 1 , wherein the volumetric proportion of the ceramic particles is at least 7 vol. %.
3. The electric insulation device according to claim 1 , wherein the volumetric proportion of the ceramic particles is below 13 vol. %.
4. The electric insulation device according to claim 1 , wherein said agglomerates are evenly distributed in said electrically insulating element.
5. The electric insulation device according to claim 1 , wherein said ceramic comprises boron nitride.
6. The electric insulation device according to claim 1 , wherein said polymer is a silicone-based polymer.
7. The electric insulation device according to claim 1 , wherein said polymer comprises:
a) a crosslinkable polyorganosiloxane, and
b) an organosilicone crosslinker.
8. The electric insulation device according to claim 1 , further comprising a voltage carrying element located in or adjacent to said chamber, wherein said electrically insulating element electrically insulates said electric voltage carrying element.
9. The electric insulation device according to claim 1 , wherein said chamber is a closed chamber the volume of which changes less than does the volume of said polymer of said element due to temperature changes.
10. The electric insulation device according to claim 1 , wherein said chamber is a closed chamber, the volume of which is constant.
11. An electric device for the transmission of medium or high voltage, further comprising the electric insulation device according to claim 1 .
12. The electric device according to claim 11 , comprising one or more elements positioned inside said chamber other than said electrically insulating element, the shape or volume of which will change during operation of said device, said one or more elements being in contact with and affecting a shape or volume of said electrically insulating element.
13. The electric device according to claim 12 , wherein said one or more elements other than the electrically insulating element comprise a medium or high voltage-carrying element.
14. The electric device according to claim 11 , further comprising an electric cable termination and said chamber is a chamber of said electric cable termination.
15. The electric device according to claim 11 , further comprising an electric power transformer and said chamber is a chamber of said electric power transformer.
16. The electric device according to claim 11 , further comprising an electric power bushing and said chamber is a chamber of said electric power bushing.
17. The electric device according to claim 11 , further comprising an electric power breaker and said chamber is a chamber of said electric power breaker.
18. The electric insulation device according to claim 1 , wherein the volumetric proportion of the ceramic particles is at least 9 vol. %.
19. The electric insulation device according to claim 1 , wherein the volumetric proportion of the ceramic particles is below 11 vol. %.
20. The electric insulation device according to claim 1 , wherein the ceramic particles form a plurality of individual agglomerates, and that the mean diameter of the agglomerates is above 200 μm.
21. The electric insulation device according to claim 1 , wherein the ceramic particles form a plurality of individual agglomerates, and that the mean diameter of the agglomerates is above 250 μm.
22. The electric insulation device according to claim 1 , wherein the amount of said compressible particles in said electrically insulating element is at least 24 vol. % and below 26 vol. % of the material of said electrically insulating element.