This project demonstrated the effectiveness of using ceramic coatings on plastic high-voltage insulators to increase their surface breakdown voltage and improve their recovery after a breakdown event.

Acree Technologies explored methods to benefit from the resiliency and ease of fabrication of plastic insulators which still have the toughness and resistance to surface flashover damage of a ceramic by coating the plastic insulator with a ceramic surface treatment.

Using this technology, high voltage insulators reap the beneht of inexpensive fabrication costs and ease-of-use of plastic insulators while having electrical performance equivalent to more expensive ceramic insulators.

Acree Technologies delivered a coated plastic insulator to the Air Force for use in a high-power pulse power device.

AirF0rce Requirement

The purpose of this project was to demonstrate the effectiveness ofusing ceramic coatings on plastic high voltage insulators to increase their surface breakdown voltage and improve their recovery after a breakdown event. l-ligh power microwave tubes, coaxial plasma guns, plasma thrusters and intense radiation sources all use large, complex shaped plastic insulators. The disadvantage of plastic insulators is that they tend to fail after repeated surface breakdown events, leading to a lowering of the voltage at which the next breakdown occurs. On the other hand, ceramic materials are less susceptible to damage and
tracking and tend to recover better than plastics.

SBIR Technology

Under this 5BlR proiect, Acree Technologies explored methods to benefit from the resiliency and ease of fabrication of plastic insulators which still have the toughness and resistance to surface flashover damage ofa ceramic by coating the plastic insulator with a ceramic surface treatment. Surface flashover occurs when the electrical held across the
face ofan insulator exceeds a given value which depends in a complex way on the material, pre—conditioning of
the surface, insulatorshape, and material history. ln many applications plastic insulators are used to hold off high
voltages. The advantage of plastic over ceramic insulators is that they are easier and cheaper to construct, particularly
for large complex shapes, and they are resilient and more durable. The resiliency of plastic insulators is particularly
important in vacuum applications where the insulator may form an integral part ofthe vacuum seal and may be subjected to compressive stresses as the chamber is pumped down.