A Low Background Noise Distributed Detection Method for Cable Partial Discharge Based on Ultraweak Fiber Bragg Grating Array

Phase sensitive optical time-domain reflectometer ($\Phi$-OTDR) is a distributed detection method for cable partial discharge. However, weak Rayleigh scattering strength restricts the minimum detection limitation of $\Phi$-OTDR in practical applications. To detect the faint acoustic signals generated by cable partial discharge (PD), a low background noise distributed detection method based on Ultraweak Fiber Bragg Grating (UWFBG) array is proposed. Firstly, this paper analyzed the essential parameters and elucidated the demodulation principles of UWFBG array. Then, experiment results proved that UWFBG array possesses advantages over $\Phi-$OTDR in eliminating dead zone, lower background noise (30dB lower than $\Phi$-OTDR), and fidelity in capturing small simulated PD signals. The sensing method proposed in this paper provided a more suitable solution than $\Phi$-OTDR for the distributed detection of cable PD.