500kV Transmission Line Lightning Transformation Evaluation Based on Improved Analytic Hierarchy Process

Reasonable protection measures can improve the lightning performance of 500-kV transmission lines and reduce trip-out rates. An assessment method based on IAHP is proposed to formulate lightning protection measures in accordance with the evaluation process of screen-selection-optimization. Based on several commonly existed lightning transformations, perform technical and economic analysis first to obtain the primary choice. Then, theoretical lightning protection measure is selected by comprehensively considering constrained factors according to the IAHP weights. Thereby, examine whether the transformation works by calculating the shielding failure rate through the establishment of EGM model, thus the optimal method is confirmed finally. The application of the method is illustrated by using a typical 500 kV transmission line under complex terrain, and the expected evaluation results have shown that the proposed protection performance can meet the transformation requirements well and guide engineering practice effectively.