Investigation into the influence of environmental conditions on power system ratings

This article presents research that seeks to assist distribution network operators in the adoption of real-time thermal rating (RTR) systems. The exploitation of power system rating variations is challenging because of the complex nature of environmental conditions such as wind speed. The adoption of an RTR system may overcome this challenge and offers perceived benefits such as increased distributed generation (DG) accommodation and avoidance of component damage or premature ageing. Simulations, using lumped parameter component models, are used to investigate the influence of environmental conditions on overhead line, electric cable, and power transformer ratings. Key findings showed that the average rating of overhead lines, electric cables, and power transformers ranged from 1.70 to 2.53, 1.00 to 1.06, and 1.06 to 1.10 times the static rating, respectively. Since overhead lines were found to have the greatest potential for rating exploitation, the influence of environmental conditions on four overhead line types was investigated and it was shown that the value of an RTR system is location dependent. Furthermore, the additional annual energy yield from DG that could potentially be accommodated through deployment of an RTR system was found to be 54 per cent for the case considered.