Study on optical detection of real partial discharges generated by different electrodes

In this work, we propose and analyze an FBG-based acoustic sensor to detect Partial Discharges (PD) in power transformers. This sensor was designed to respond to the Acoustic Emissions (AE) resulting from the discharges, using a mandrel-shaped transducer with an FBG attached to its surface. We obtained the frequency response of the sensor and compared to the response of a piezoelectric hydrophone. While the hydrophone responded to 50 and 200 kHz, the optical sensor responded to 16 and 40 kHz. We also generated PD using two types of electrodes connected to a sparkler, measuring AE with the FBG and with the hydrophone. We observed that the optical sensor and piezoelectric have similar responses, confirming the feasibility of the proposed transducer.