Research And Implementation Of State Evaluation System For Overhead Transmission Lines

With the rapid development of power system and the continuous expansion of power grid,the operation state of overhead transmission lines,as an important part of power system,directly relates to whether the whole power system can operate safely,stably and efficiently.In order to ensure the safety and reliability of the lines,it is necessary to evaluate the operation state of the line equipment scientifically and rationally to know the equipment condition timely and accurately,and to carry out the condition-based maintenance.As a prerequisite and foundation for condition-based maintenance,the results of the state evaluation of transmission lines directly affect whether the maintenance strategy is reasonable or not.Therefore,using scientific and effective methods to evaluate the operation state of overhead transmission lines has important practical significance and application value.By analyzing existing methods of state evaluation,this paper presents a method of state evaluation based on hierarchical model and fuzzy reasoning.By using the hierarchical model,the four-layer structure of state evaluation is established,and the operation state of the eight line units,towers and lines is obtained in turn by fuzzy reasoning.At the same time,according to the guideline of transmission line's state evaluation of State Grid Company and Zhejiang Electric Power Company,a new and improved guideline of line's state evaluation has been made.According to the characteristics of the line,the guideline not only combines internal factors of line equipment,such as the basic information of the lines,on-line monitoring information,routine inspection and test information,but also combines external factors,such as environmental information,weather information,and constructs a more comprehensive index system of line's state evaluation.Based on the research of state evaluation method and guideline,state evaluation software system of transmission lines is designed and developed.The system includes many function modules,such as state evaluation guideline management,state evaluation information collection,line's state evaluation,evaluation results statistical query and evaluation results map display.It can not only evaluate the current state of lines,but also evaluate the historical state and simulate the future state evaluation.The actual operation results show the effectiveness and reliability of the system,which can provide decision-making basis for making maintenance plans to make the transmission lines operate safely and stably.