Compact dry-type transformer
The present disclosure relates to transformers. Various embodiments of the teachings herein may include a coating of an insulation body of a dry transformer. For example, the electrical winding may include multiple windings of a winding conductor wound to form a coil. The coil has been embedded into a solid insulation body. In some embodiments, a coating of an electrically conductive material, comprising a resin matrix and microscale filler, has been applied to at least one surface of the insulation body.
1. An electrical winding for a dry transformer, the electrical winding comprising:
a winding conductor wound in multiple windings to form a coil;
the coil embedded in a solid insulation body;
a coating with a particular sheet resistance on a surface of the insulation body;
wherein the coating comprises a resin component and a microscale and electrically conductive filler present in a particle size in the range from 1 μm to 2 mm;
wherein a sheet resistance of the coating is defined via setting a ratio of at least two filler particle fractions.
2. The electrical winding as claimed in claim 1 , wherein filler is present in the coating in an amount of more than 20% by weight and/or more than 10% by volume.
3. The electrical winding as claimed in claim 1 , wherein the coating completely covers the surface of the insulation body.
4. The electrical winding as claimed in claim 1 , wherein the coating comprises semiconductive material.
5. The electrical winding as claimed in claim 1 , wherein the coating has includes at least two filler particle fractions.
6. The electrical winding as claimed in claim 1 , wherein the surface resistance of the coating is 102Ω/□ to 105Ω/□.
7. The electrical winding as claimed in claim 1 , wherein the coating comprises water as solvent.
8. The electrical winding as claimed in claim 1 , wherein the coating is grounded.
9. An electrical winding for a dry transformer, the electrical winding comprising:
a winding conductor wound in multiple windings to form a coil;
the coil embedded in a solid insulation body;
a coating with a particular sheet resistance on a surface of the insulation body;
wherein the coating comprises a resin component and a microscale and electrically conductive filler present in a particle size in the range from 1 μm to 2 mm;
wherein a sheet resistance of the coating is defined via setting a ratio of coated to uncoated filler particles.
10. The electrical winding as claimed in claim 9 , wherein filler is present in the coating in an amount of more than 20% by weight and/or more than 10% by volume.
11. The electrical winding as claimed in claim 9 , wherein the coating completely covers the surface of the insulation body.
12. The electrical winding as claimed in claim 9 , wherein the coating comprises semiconductive material.
13. The electrical winding as claimed in claim 9 , wherein the coating has includes at least two filler particle fractions.
14. The electrical winding as claimed in claim 9 , wherein the surface resistance of the coating is 102Ω/□ to 105Ω/□.
15. The electrical winding as claimed in claim 9 , wherein the coating comprises water as solvent.
16. The electrical winding as claimed in claim 9 , wherein the coating is grounded.