Abstract
The AC interference between High Voltage AC (HVAC) power lines and pipelines has been modeled with various software programs, all of which have a variety of input data which creates various results and outputs. Important aspects such as the soil resistivity along the pipeline route can have a significant impact on the pipelines coating resistance. This in turn can affect both the computed AC voltages and more specifically the current densities, both of which can significantly affect personal safety and corrosion of the pipeline. The spacing of the soil resistivity measurements can have a significant effect on the accuracy of the modelling results, which in turn can affect the mitigation design and integrity. For example, measurements at 1,000 ft vs. 5,280 ft can have dire consequences on the accuracy of the modelling, the understanding of the interference, and therefore how an owner/operator responds to the threat.
However, the measurements themselves do not affect the corrosion threat. Other aspects such as the power line Longitudinal Electric Field (LEF) or Electro-Magnetic Force (EMF) may also be used to “calibrate” the AC Interference computational model, especially where power-line load data is absent. This paper addresses the critical importance of collecting adequate data for the AC Interference studies, to prevent costly installations and to mitigate the incorrect positioning of AC Mitigation systems, due to inadequate information.
