Material for insulation system, insulation system, external corona shield and an electric machine
High-voltage insulation systems are simplified and can have a thinner design by the use of an external corona shielding system that may include an electrically conductive PTFE fabric. Thermal conductivity may also be improved.
1. An external corona shielding system comprising:
an inner external corona shielding winding;
an outer external corona shielding; and
a perforated tape positioned between the inner external corona shielding winding and the outer external corona shielding, and the perforated tape comprising:
a woven fabric at least partially composed of fibers comprised of a hydrophobic material, and an electrically conductive material positioned between the fibers, wherein the fibers insulate against conducting electricity between the fibers.
2. The system as claimed in claim 1 , wherein the perforated tape comprises electrically conductive PTFE.
3. The system as claimed in claim, 1 wherein the hydrophobic, electrically conductive material of the woven fabric is composed of electrically conductive PTFE.
4. The system as claimed in claim 1 , wherein the perforated tape is perforated with perforations shaped, sized and positioned to be infiltrated by a vacuum pressure impregnation process.
5. The system as claimed in claim 1 , wherein the hydrophobic material is coated with an electrically conductive layer.
6. The system as claimed in 1 , wherein the electrically conductive material comprises graphite.
7. The system as claimed in claim 1 , wherein the electrically conductive material is mixed into a hydrophobic material.
8. The system as claimed in claim 1 , wherein the electrically conductive material comprises fibers distributed between the fibers or in the woven fabric structure.
9. The insulation system as claimed in claim 1 , wherein the hydrophobic material has pores shaped, sized and positioned to be infiltrated by a vacuum pressure impregnation process.