The Overhead Transmission Line Research Of Operating Mode Reliability About Fault Tree Analysis

FTA is shortened form fault tree analysis which began in Amreican about 60 ages. The FTA was used to evaluating fault for generating set or transformer, and had a good result at that time. Now, the fault tree analysis has become a mian method and effective tool to evaluating reliability for complex system. But the safety evaluation, that overhead transmission line research of operating mode reliability about fault tree analysis, is to be in blank stage basically.Though building the fault tree, we can get the weak line and state probability between system and partment from evaluating reliability for system running state. The reliability of system running state can be deduced from fault tree analysis. Acrooding to developing about state grid step-by-step the power network and its line structure become more and more complex. The line's safty and reliability operation have very important value for power system. The importance of safty evaluation about overhead transmission line operating mode reliability is been known by more and more people. But in fact, the overhead transmission line has a lot of aspect like extensive distributed area, more detected parameter, and complex operational entironment and so on. It leads to redundancy data and difficult analysis directly. For this reason, we need a short-cut and effective evaluating utility method.This article is to bring up a new evaluating method which named FTAfor the overhead transmission line operating mode. This method usesFussell-Vesely method in fault tree analysis to figure out minimum cut set ofoverhead transmission line and uses minimum cut set theory to build faulttree. To combine weight which is given by field expert and calculation fromfault tree, we can get computational formula for calculare overheadtransmission line evaluating reliability at same time. Through this model canfind the weak link and incipient fault of system through analysis andevaluate. This article combines the data which collected from field andfigure out the reliability data to all levels of diiferent overhead transmissionline operating mode. This calculates got a good result. This text uses VisualBasic language and visual interface to programming mathematics method.This programe has compatibility of software which power system has nowand good effect of man-machine conversation. It can give a point tooverhead transmission line operating mode and find out the weak line insystem. It also canbe used to look up the detailed information and evaluatingresult by call the inherited line data. And using the calculate function in programe to evaluating new overhead transmission line operating mode. The example shows that the mathematical model is short-cut and effective. It has extensive application foreground.