Investigations on the Revision in the Eccentricity Limits to Improve the Performance of Extruded HVDC Cables

This paper highlights the problems associated with a prevalent defect in extruded HVDC cables called eccentricity, which refers to an uneven thickness of insulation in the cable cross-section. IEC 62067 specifies an upper limit of 10% on the allowed eccentricity. However, this limit needs to be revised owing to the electro-thermal instability concerns, as discussed in this paper. Based on comprehensive electro-thermal FEM simulations, the authors investigate the effect of eccentricity under different operating conditions of the cable and thereby suggest appropriate revision to the standard.