Field Test and Analysis of Interference of High or Ultra High Voltage Direct Current Transmission System to Underground Steel Pipeline

The minimum distance between the Hami ground electrode in Hami South-Zhengzhou ±800 kV ultra high voltage direct current (HVDC) transmission system and the West-East gas pipeline system is 44 km. The change of pipe-to-soil potential was monitored and tracked along the West-East gas pipelines during the periods of the transmission line operating in the monopolar configuration with earth return. By analyzing the test data, the interference range and degree of Hami grounding electrode to the West-East gas pipeline were obtained, and the interference law to the pipe-to-soil potential was also mastered under different operating modes of HVDC.