Performance Assessment of Overhead Conductors Subjected to Combined Thermal and Wind Loads

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The overhead power conductors carry electricity power from distribution feeders to consumers, providing a necessary service. Aluminium Conductor Steel Reinforced (ACSR) and All Aluminium Conductors (AAC) are widely utilised in the Australian power distribution network. ACSR offers increased strength and conductivity by combining both steel and aluminium strands while AAC offers proper conductivity and lightweight powerlines. Due to factors like current flow, extremely elevated ambient temperatures, direct sunlight exposure, and short circuit currents, these conductors can be subjected to elevated temperature levels. Operating at higher temperatures can alter the mechanical characteristics of the conductor materials. Consequently, the mechanical strength of conductors diminishes when powerlines consistently operate under these conditions. Conductors are set up in various environmental conditions, resulting in different wind load impacts. While the temperature rise can be somewhat offset by these wind variations in terms of cable strength, wind action still introduces additional tensile stress in the conductor. Hence, this research aims to determine the combined effects of thermal and wind factors in the performance of ACSR and AAC cables. The laboratory experimental testing was performed to determine the decrease in the tensile strength of conductors under steady-state elevated temperature scenarios. The Australian standard prediction for wind and thermal conditions is considered for the calculation of the required strength in the conductors. Finally, the long-term safety performance of both ACSR and AAC cables was evaluated by considering the combined effect of temperature and wind effects.