Partial Discharge Monitoring and Localization in HV Bushings Using Fiber Optic-based Acoustic Emission Sensing Technology

Partial discharges (PD) in high-voltage (HV) bushings are a critical early indicator of insulation degradation and can lead to catastrophic transformer failures if undetected. Conventional electrical PD measurements (IEC 60270) are often challenged in in-service substations by electromagnetic interference (EMI), limited localization capability, and restricted access to test taps. Acoustic emission (AE) techniques provide a complementary approach; however, conventional piezoelectric sensors are limited by EMI susceptibility, the need for powered electronics, and reduced flexibility for multiplexed monitoring. This paper presents an industrial evaluation of fiber optic acoustic emission (FOAE) sensing for PD detection and monitoring in HV bushings, using point sensors rather than distributed…