Performance comparison of existing AC and DC transmission lines within southern Africa with predictions for lines above 765 KV

摘要

Transmission line faults caused by lightning, contamination, birds and fires largely determineudthe performance of AC and DC transmission line within Southern Africa. With the trendudtowards higher voltages, with specific reference to the Westcor HVDC link, been developed,uda comparison of the performance between existing AC and DC lines will give insight notudonly into how the faults perform relative to each system but also what can be expected forudlines exceeding 765 kV. This dissertation compares data for all the 400 kV transmission linesudin South Africa and the ±533 kV Cahora-Bassa line, with reference made to the existing 765udkV AC lines in South Africa. Based on this comparison the findings include possible dataudacquisition inconsistencies, underperforming areas with respect to different fault types andudperformance predictions for lines exceeding 765 kV.