Research On On-line Monitoring Technology For Galloping And Wire Breakage Of Transmission Lines

With the increasing demand of energy,the transmission lines have developed a lot.While exposed to outdoor,they are easily broken down by external force.It will directly affect the society if the transmission lines break down.The main factors which affect the safety of transmission lines are galloping and broken wires.Therefore,it is important to develop an efficient and feasible monitoring technology.Up to now,there is no reliable way to detect broken wires.The ultrasonic guided waves detection technology is a new nondestructive testing technology.It can detect long distance with a single point of excitation,so it is significant to research on broken wires.It is convenient to use motion sensor to detect the transmission lines’angle and displacement.According to the aforesaid background,this paper puts forward the study on the monitoring technology for transmission lines.Additionally,this paper is committed to develop the monitoring terminal device,and determine the mode and frequency of Guided Wave to detect the transmission lines,testing propagation characteristics and defects of Guided Waves,and put forward an algorithm for detect the transmission lines’ angle and displacement,and design the detail solution for transmission lines monitoring system.The details of this dissertation were presented as follows:Chapter 1,the factors of affecting transmission lines’ safe and the importance of transmission lines monitoring is discussed.then,the testing method and research status and development trends of transmission lines in monitoring were summarized.Last,the way to solve the problem of transmission lines monitoring was proposed.Chapter 2,the influencing factors of overhead transmission line monitoring is discussed,then the solutions are provided.According to the demand and influencing factors,a scheme for the monitoring system of transmission lines is designed.Chapter 3,the concept and characteristics ultrasonic guided wave is introduced.Then,the frequency dispersion curves exists in the transmission lines is obtained by using the method of SAFE,and the ultrasonic guided wave propagation characteristic in the transmission lines is analyzed.Then,a proper mode and transducers for transmission lines monitoring is found out.Then,the dispersion and attenuation characteristics of longitudinal mode guided waves on transmission lines are verified by experiment.At the same time,different types of defects are detected by experiment.Chapter 4,the method of galloping monitoring and angle calculation is introduced.Then,the galloping measurement and standard processing method of motion sensor is proposed.Next,this paper puts forward a way to calculate angle by Kalman filter algorithm and a way to calculate displacement by integral processing.Last,two methods is verified by experiment.Chapter 5,according to the design scheme of the monitoring system,the detail modules are introduced,the experimental testing system is built,and the comprehensive system testing is carried out.Chapter 6,the main work and conclusion are summarized and the prospect for future research are put forward.