Online Detection of Partial Discharges in Medium and High Voltage Cable Accessories by Acoustic Emissions

Abstract

The acoustic waves caused by partial discharges inside a dielectric can be detected by sensors of acoustic emissions (EA) and analyzed in the time domain. The experimental results that are presented, demonstrate the capability of online detection of these sensors, in the vicinity of a cable, splice or terminal accessory. The EA sensors are immune to electromagnetic interference, are a non-destructive detection method and guarantee galvanic decoupling from the voltage network; This technique of detection of partial discharges can be applied as a test method for preventive or predictive maintenance (maintenance based on the condition), in equipment or installations of medium and high voltage in service and represents an alternative to electrical detection systems, conventional or not, which continue to be based on the detection of current pulses.