Fluctuation Regularity of Stray Current Interference from Rail Transit to Wuhan Gas Pipelines

The pipe-to-soil potentials of the gas pipelines under the dynamic DC interference of Wuhan rail transit were continuously monitored for 24 h. The interference risk was evaluated and Fourier transform was used to analyze the data in frequency domain. The frequency, distribution, amplitude and other dynamic characteristics of pipe-to-soil potential fluctuation under the interference of stray current were analyzed. The results show that there were 20 points of gas pipelines in high DC interference risk zone and 7 points in low risk zone. The fluctuation of pipe-to-soil potentials under the interference of trams was intermittent, an entire intermittency period was 130-140 s, but it was not intermittent under the interference of metros. Though the fluctuation frequency caused by various rail transit lines was different, more than 50% fluctuation frequency was concentrated in 0.005-0.03 Hz.