Four-terminal parameter formulation of solving induced voltages and currents on a pipeline system

An analytical method of calculating steady-state induced voltages and currents on a complex pipeline system based on a four-terminal parameter has been developed. The developed method makes it very easy to deal with and at the same time to understand the effect of the system parameters, inducing currents and boundary conditions that are different in each section of the pipeline system. Analytical results show that there exists a position where the pipeline voltage to ground becomes zero. When both ends of the pipeline are grounded through a resistance, the position of the zero potential is nearly the centre of the pipeline. If one end is open-circuited, the other end shows zero potential. This fact has not been well recognised by engineers in this field. Also, the effect of the inducing currents, which are different in each section along the pipeline, is explained from the physical viewpoint based on the analytical results. The accuracy of the proposed method is confirmed to be satisfactory in comparison with Electromagnetic Transients Programme (EMTP) simulation and field test results.