The Dielectric Characteristics of SiC/PEEK for Outer Corona Protection in Large Generator

ABSTRACT For the SiC /epoxy resin composites which are commonly used for end corona protection ( ECP ) in large generator stators and are prone to wear failure, this study investigates the applicability of thermoplastic alternatives poly(ether ether ketone) ( PEEK ), providing new material directions for future research. Conductivity and dielectric property studies were conducted on pure PEEK and samples with varying contents of nano‐silicon carbide. The conductivity of the films was measured in the temperature range of 30°C–200°C and the electric field range of 1–3 kV /mm. Results showed that the film with 5% silicon carbide exhibited the highest conductivity, with a nonlinearity coefficient of approximately 0.98. An Arrhenius analysis was conducted to understand the conduction mechanism and to obtain the trap activation energy. Dielectric spectroscopy revealed the dielectric loss characteristics, and fitting with the Havriliak–Negami ( HN ) model indicated different relaxation mechanisms in the studied samples. Given sample test results compliance with the required conductivity and nonlinearity coefficients, along with their lower dielectric loss and field dependence on temperature and electric field, PEEK films doped with 3% silicon carbide present a promising potential replacement for epoxy resin in the ECP in generators.