Research on Electro-Acoustic Synergistic Partial Discharge Detection Technology for Cable Terminations

Area of Science:

• Electrical Engineering
• Materials Science
• Physics

Background:

• Partial discharge (PD) detection in high-voltage cable terminations suffers from limited spatial localization accuracy.
• Traditional ultrasonic detection methods face challenges in accurately determining the trigger time for PD events.

Purpose of the Study:

• To develop and demonstrate an electro-acoustic synergistic localization technology for improved PD detection.
• To enhance the spatial localization accuracy and trigger time determination for PD in cable terminations.

Main Methods:

• Developed a high-sensitivity Sagnac acoustic sensor using a 3D-printed photosensitive resin mandrel with a resonant response at 33.2 kHz.
• Constructed an electro-acoustic synergistic detection system utilizing a high-frequency current transformer (HFCT) for electrical time reference and a dual-channel Sagnac sensor array for ultrasonic wave arrival times.
• Tested the system in a 12 kV laboratory cable-termination PD experiment.

Main Results:

• The Sagnac acoustic sensor demonstrated narrow-band, high-sensitivity characteristics for weak PD ultrasonic signals.
• The electro-acoustic synergistic system achieved an absolute localization error of 5 mm for a representative built-in air-gap PD source in the laboratory setup.
• The system successfully combined the fast electrical response of HFCT with the electromagnetic-interference immunity and acoustic sensitivity of Sagnac fiber-optic sensing.

Conclusions:

• The proposed electro-acoustic synergistic localization technology offers a promising approach for accurate PD detection in high-voltage cable terminations.
• This study provides a proof-of-concept for integrating electrical and optical sensing for enhanced PD source identification.
• The developed Sagnac acoustic sensor shows potential for detecting weak ultrasonic signals crucial for PD monitoring.