Corona shielding strip for a high-voltage rotating electrical machine

A corona shielding tape for further processing to produce an insulation system comprising an impregnated winding with potential control via outer corona shielding “AGS” and/or internal potential controller “IPS” and/or terminal corona shielding “EGS”, the insulation system produced by impregnating the winding with an anhydride-free and resin-based impregnating agent at 45-85° C. and under reduced pressure, the corona shielding tape comprising:

• a carrier tape;
• a tape adhesive;
• an electrically conductive and/or partly conductive filler in a polymer matrix;
• and
• a tape accelerator suitable for curing and/or gelation of the impregnating agent;
• wherein the filler comprises at least one component selected from the group consisting of:
• antimony-doped tin oxide, silicon carbide, and aluminum-doped silicon carbide;
• the polymer matrix contains at least one polyvinylalcohol and/or a polyvinylalcohol copolymer;
• the tape adhesive, the filler, and the tape accelerator are inert to each other and therefore stable in storage at a temperature from 6 degrees to 23 degrees C. for six months;
• and
• the accelerator comprises at least one of a superacid or a superacid salt including a sulfonium cation suitable for acceleration of a cationic homopolymerization of the resin-based anhydride-free impregnating agent.