Monitoring the manufacturing process and the operation of high-voltage bushings with fiber optics

Fiber Bragg Gratings (FBGs) were used to monitor the manufacturing process and the operation of high voltage bushings. During operation, temperatures at several points inside the bushing were monitored. In another test, during bushing manufacturing, FBGs monitored the filling and curing process of the epoxy in Resin Impregnated Paper (RIP) bushings. Traditionally, temperature measurements inside the bushing core have been performed using thermocouple probes and only in bushings for research, not final products. The use of appropriate FBGs was successfully tested in the harsh environments of operation (under high voltage) as well as in manufacturing (high curing temperature and stress). The results demonstrate the potential of fiber optics to study and improve production methods. The study also shows that fiber optics are suitable for long-term monitoring during bushing operation.