Testing and Assement of AC Interference on Buried Steel Pipelines

AC interference on buried steel pipelines can cause AC corrosion and destroy cathodic protection (CP) system when pipelines are layed down near a high voltage AC power transmission line or electric railway. So, it is necessary to the test and assess the AC interference from the high voltage AC power transmission lines or electric railway. The test and assessment parameters of AC interference at home and abroad are mainly concerned with the AC voltage, AC current density, corrosion rate, AC/DC density ratio and so on. By studying time-frequency domain characteristics of pipe-to-soil potential signal of buried steel pipelines, there is consistency between the time frequency of pipe-to-soil potential signal and frequency of AC interference source, thus provides a basis for test and judgment of AC interference on buried steel pipelines.