Electrical design for the conversion of existing UK HVAC overhead lines to HVDC operation under severe pollution conditions, ranging from 170 to 500 kV DC

This paper provides the HVDC electrical design of three existing UK HVAC overhead lines, two of which constitute 85% of the UK transmission overhead line system. The designs are based on CIGRE and IEC recommendations. Also, the verification of the electrical stress requirements on the insulators is performed by means of finite element simulations. The paper shows that the HVDC converted tower lines would carry 1.6 to 2.9 times the power of the original HVAC lines, depending on tower type, insulation arrangement, and environmental conditions.