End winding corona protection
An end winding corona protection including a winding of a rotating electric machine, having a conductor and a groundwall insulation surrounding the conductor, an end winding corona protection arranged on the outer surface of the groundwall insulation, the end winding corona protection comprising a first layer characterized in that the surface resistance of the first layer is in the range of 10 Ohm to 80 Ohm, and in that the end winding corona protection further comprises a second layer arranged on the outer surface of the first layer, wherein the second layer is made of semiconductive material, and wherein third layer is arranged on the outer surface of the second layer and made of medium resistive material.
1. A winding of a rotating electric machine, comprising
a conductor and a groundwall insulation surrounding the conductor, and
an end winding corona protection arranged on the outer surface of the groundwall insulation,
wherein the end winding corona protection comprising a first layer;
wherein the surface resistance of the first layer is in the range of 10 Ohm to 200 Ohm, and in that the end winding corona protection further comprises a second layer arranged on the outer surface of the first layer,
wherein the second layer is made of semiconductive material with a resistance of the second layer perpendicular to the surface is in the range of 100 MOhm/mm 2 to 10 6 MOhm/mm 2 , and
wherein the end winding corona protection further comprises a third layer arranged on the outer surface of the second layer, the third layer having a surface resistance in the range of 1 kOhm to 10 kOhm.
2. A winding according to claim 1 ,
wherein the surface resistance of the first layer is in the range of 20 Ohm to 80 Ohm.
3. A winding according to claim 2 ,
wherein the surface resistance of the first layer is in the range of 30 Ohm to 80 Ohm.
4. A winding according to claim 1 ,
wherein the resistance of the second layer perpendicular to the surface is in the range of 1000 MOhm/mm2 to 10 5 MOhm/mm 2 .
5. A winding according to claim 4 ,
wherein the resistance of the second layer perpendicular to the surface is in the range of 1000 MOhm/mm2 to 10 4 MOhm/mm 2 .
6. A winding according to claim 1 ,
wherein the third layer has a surface resistance in the range of 1 kOhm to 8 kOhm.
7. A winding according to claim 6 ,
wherein the third layer has a surface resistance in the range of 2 kOhm to 5 kOhm.
8. A winding according to claim 1 ,
wherein at least one layer is applied in the form of a tape.
9. A winding according to claim 1 ,
wherein at least one layer is applied in the form of paint.
10. A winding according to claim 1 ,
wherein the overall thickness of all three layers is 0.8 mm or less.
11. A winding according to claim 10 ,
wherein the overall thickness of all three layers is 0.5 mm or less.
12. A winding according to claim 11 ,
wherein the overall thickness of all three layers is 0.3 mm or less.
13. A rotor of an electric machine with a winding according to claim 1 .