Abstract
The present paper develops a numerical simulation method of steady-state and transient voltages and currents on a gas pipeline by applying a generalized circuit analysis program EMTP which is realized as a worldwide standard software. A buried gas pipeline is represented as an underground cable consisting of a tubular core and its outer insulator. The series impedance and the shunt admittance are easily evaluated by the EMTP supporting routine Cable Parameters. The paper has carried out simulations of steady-state and transient voltages and currents along the buried gas pipeline by EMTP. Based on the simulation results, it has become clear that the distributions of the voltages and the currents along the pipeline differ notably in the front and in the rear of a fault position. Thus, a detecting method is developed by observing a difference of a voltage amplitude between sound and fault states. The proposed techniques are investigated on real gas pipelines based on EMTP simulations, and it has been confirmed that the technique can be used in practice.
