Analysis of electromagnetic coupling of HVAC cable section partly installed in parallel with HVDC lines in one corridor

•A new methodology is presented to calculate the coupling components of HVAC line.•Coupling components on HVDC line partly paralleled with HVAC line were studied.•The key factors affecting the coupling between HVAC and HVDC line were analyzed.•Suggestions are drawn to optimize the coupling components on HVDC line.

For HVAC and HVDC transmission lines which are partially in parallel in one corridor, coupling parameters between AC and DC transmission lines can be changed due to the length of extension sections which are not in parallel. And the generated electromagnetic coupling components at the two terminals of the DC line contain the effects of line parameters of extension sections. In this paper, the coupling components on the DC line, not all of which is in parallel with the AC line are studied in detail. The DC line is longer than the AC line and it may have extension sections on the both sides. Firstly, a new methodology is presented to calculate the coupling components of HVAC line upon HVDC line in the above situation. Then, the correctness and applicability of this method is illustrated and validated through a case study. Meanwhile, the key factors affecting the coupling between the AC and DC lines are analyzed. Finally, some suggestions have been proposed to provide as a construction reference which aims to optimize the electromagnetic coupling components on the DC line.