Understanding the need for anti-corona materials in high voltage rotating machines

As operating stresses in high voltage motors and generators increase, the importance of using the correct conductive and stress grading tapes also increases. Surprisingly, neither national nor international standards exist for this aspect of rotating machine technology. This paper describes tests carried out to simulate practical conditions which exist on coils and bars made using both Resin-Rich and VPI technology. It also gives recommendations on how the tapes should be applied and how measurements should be made.