HVDC Cable–Pipeline Interaction Under Fault Conditions: Induced Currents, EPR, and Safety Implications

Current (HVDC) land cable systems and parallel gas pipelines, with a particular focus on safety implications under fault conditions. The methodology involves constructing a detailed electrical model of a representative submarine HVDC link. The model incorporates all relevant joint bays

(JBs) and transition joint bays (TJBs), which serve as grounding points and significantly affect

EM coupling. Two primary cases are analysed. In Case #1, the pipeline is electrically isolated from cable grounding points, so only inductive coupling occurs. The impulsive nature of the induced currents is evaluated using the human body equivalent circuit, and the resulting body currents are found to be below safety thresholds for the studied configuration. In Case #2, the pipeline’s midpoint coincides with an earthed JB, introducing both inductive and conductive couplings. Faults at or near the earthed JB result in significant potential gradients along the pipeline. This scenario demonstrates the importance of earth potential rise (EPR) in the magnitude of voltages that can appear across the pipe coating. The results show the necessity of detailed and system-specific modelling to accurately assess EM interference and safety risks in HVDC cable and pipeline corridors. The findings indicate that, for the studied scenarios, induced voltages and body currents remain within safe limits, but highlight the need for further research and standardization. The paper concludes with recommendations for incorporating such detailed analyses into design practices and standards development.