Detection of Partial Discharges of Corona Type in Paper Oil Insulation System by Optical Method

Optical method of PD measurement is still in research stage and not very widely/commercially adopted for PD measurement. Therefore there is a scope for exploring, investigating and studying the feasibility of optical method for PD measurement. A study was undertaken in the laboratory of CPRI to understand the detection capability of optical method in paper oil insulation system. Partial discharges of corona type has been simulated with point-plane electrode configuration in paper oil insulation system. An Optical PD measurement system consists of fluorescent optical fiber, mating sleeve, common optical fiber, photomultiplier tube module and data acquisition unit has been used for the investigation. From the experimental investigations it is concluded that optical PD measurement system is capable of detecting partial discharges of corona type. It is a promising tool for online partial discharge monitoring of oil filled transformers.