Abstract: In order to effectivelyreduce thelightning incidents of power transmission lines and ensure the safety of power systems,some measures should be adopted to improve the lightning withstand level of transmission lines.In this paper,based on an improved analytic hierarchy process ( AHP) with new scale and the fuzzy comprehensive evaluation method ( FCEM) ,a model suitable for evaluating the lightning protection measures of actual lines in power distribution networks is proposed,which comprehensively considerssuch factors as the reduction of trip-out rate,the impact of engineering cost,the effect of the target,the ease of maintenance andthe service life.Then,in accordance with the AHP,all the evaluation weights of lightning protection measures relative to the destination level are obtained,the memberships of the measures are determined via the FECM,and the optimal rehabilitation scheme is thus presented.The results show that the proposed evaluation system helps to effectively assess the power distribution lines and determine the optimal lightning protection measures as well as line rehabilitation scheme.

Key words: lightning protection, improved analytic hierarchy process, fuzzy comprehensive evaluation, new scale, effect evaluation