Disturbed partial discharge detection system based on an improved Φ-OTDR assisted by a wFBG array

Area of Science:

• Electrical Engineering
• Materials Science
• Optical Sensing

Background:

• Partial discharge (PD) detection is vital for assessing power cable insulation integrity.
• Traditional PD detection methods face challenges in sensitivity and real-time monitoring.
• Optical sensing offers a promising alternative for enhanced diagnostic capabilities.

Purpose of the Study:

• To propose and demonstrate a novel disturbed acoustic sensing (DAS) system for online partial discharge (PD) detection.
• To enhance the sensitivity and signal-to-noise ratio (SNR) for detecting ultra-small fiber strains caused by PD.
• To validate the system's performance on a 10 kV cross-linked polyethylene (XLPE) power cable.

Main Methods:

• Utilizing a phase-sensitive optical time-domain reflectometry (Φ-OTDR) based DAS system.
• Incorporating a weak fiber Bragg grating (wFBG) array into the sensing fiber to boost SNR.
• Packaging the sensing fiber with aluminum tape to improve sensitivity.
• Conducting experiments on a 10 kV XLPE power cable with artificial defects.

Main Results:

• Consistent detection of partial discharge (PD) signals was achieved in the XLPE power cable.
• The introduced wFBG array and aluminum tape packaging significantly enhanced signal detection.
• Characteristics of the detected PD signals were successfully analyzed.

Conclusions:

• The proposed Φ-OTDR-based DAS system is effective for online PD detection in power cables.
• The integration of wFBG and specialized packaging offers a viable solution for improving PD monitoring sensitivity.
• This technology contributes to more reliable power cable insulation assessment and maintenance.