Study On System For On-line Monitoring And Assessment Of Overhead Transmission Lines Galloping

The damages caused by overhead transmission lines galloping are usually due to too large galloping amplitudes, causing interphase flashover, broken strand, collapse of support incidents, leading to economic losses and casualties. The safety and reliable of transmission lines operation are seriously affected. China is the disaster-stricken area of galloping, eight of nine typical meteorological districts have natural conditions for galloping, the galloping accidents remain fresh in our memories caused by snow disaster in 2008. Therefore, this issue is attached great importance by our country. As the transmission lines galloping is affected by many factors, such as icing, temperature, humidity, wind speed, parameters of line structure, it makes the real-time monitoring and accurate evaluation of the state of lines galloping more difficulty.The paper summarizes the existing on-line monitoring devices of transmission lines galloping, and the on-line monitoring system of transmission lines galloping is developed using sensor technology. The new micro-acceleration sensor monitoring the lines galloping data is adopted by the system, the signals are processed by SCM, and the data are transmitted to the host computer by GSM module.As the state evaluation of the transmission lines galloping has the characteristics such as fuzziness and randomness, according to the existing achievements and the expert experiences, on the basis of the analysis for the factors affecting the state of transmission lines galloping, considering the practical operation, the multi-layer fuzzy evaluating method based on the FAHP for transmission lines galloping is presented to satisfy the need of state evaluation. The assess index system is established, it contains character parameters, environment factors, history data, etc. First, the fuzzy analytic hierarchy process is applied to determine the constant weights of every index. Secondly, the variable weights formulation based on the balanced functions is used to correct the constant weights and get the variable weights. Finally, the membership degree function of each index is determined by different fuzzy function to ensure the accuracy of the fuzzy discrimination matrix. The feasibility of this method presented above is demonstrated by the practical application examples.The procedure for monitoring and assessment of transmission line is compiled based on the platform of LabVIEW, man-machine communication interface is designed, the galloping data acquisition and processing are carried out, and the evaluation of galloping state is achieved. The simulating test platform for transmission lines galloping is built in the laboratory, and the system running test is carried out, the results show that the terminal can achieve real-time monitoring for the state of transmission lines galloping, this evaluative method can more accurately assess the state of transmission lines galloping. The system has the feature of good practicability and reliability, offering a way of getting the state of lines galloping and guidance for monitoring transmission lines galloping.