Study Of A Reliability Assessment Method Of Overhead Transmission Line Based On Fault Tree

The overhead transmission line is one of the most important components of thetransmission system, whose running state directly affects the reliability of the entirepower system operation. Correctly assessing the reliability level of the runningoverhead transmission lines is the key to the success of state maintenance. Therefore,timely and accurately grasping of reliability level of overhead transmission lines hasimportant theoretical and practical value.After using failure mode and effect analysis on overhead transmission lines, theoverhead transmission line reliability assessment model was established in the paper,and also the determination method of model parameters such as important degree andthe failure probability.The main research contents and conclusions are as follows:1) Using the failure mode and effect analyzes (Failure Mode and Effect Analysis,FMEA), based on comprehensive consideration on the various components andfunctions of overhead transmission line, the FMEA list of overhead transmission line iscompleted, and the main failure modes of overhead transmission line are determined.2) Based on the logical relationship between failure modes and fault tree analysis,the fault tree model of overhead transmission lines is established. Aiming at thedeficiency of quantitative analysis method in traditional fault tree model that probabilityimportance of each event is equal, the reliability assessment method of overheadtransmission line based on fault tree is set up.3) According to operating code for overhead transmission and the relatedevaluation guide and the statistical analysis of FMEA, the corresponding relation ofeach component failure mode and the fault features are concluded; this paper putsforward the comprehensive evaluation method of fault probabilities based on therelative inferiority degree and membership function.4) The reliability evaluation of the500kV overhead transmission lines inChongqing are carried out. The evaluation results show that the evaluation method canmake correct assessment according to the relevant operating data of the overheadtransmission lines and has certain practical value.