Research On Icing Density On-line Monitoring Technology Of Transmission Lines

Overhead transmission lines are vulnerable to icing and snow disasters during the long-term operation.And serious icing is easy to induce severe power safety accidents such as large area tower overturning,breaking line,flashover tripping and so on.A great deal of research on transmission lines icing have been carried out both here and abroad.However,the existing research and calculation methods are short of relevant study of on-line monitoring of icing density,which mostly adopt the estimated value or pure ice density during the ice-coating and thawing calculation and will cause unavoidable error to the calculation results.Therefore,it's of great significance to find a real-time and on-line monitoring method and sensor on the monitoring of icing density.Based on the theoretical research on the icing mechanism and capacitance measurement technology,the measuring principle of capacitance method and difference of icing density are introduced detailed in this paper,then the feasibility of icing density measuring by capacitance method is proved theoretically.A variety of ice coating(density)types were obtained in different experimental environment by adjusting the parameters of the artificial icing chamber,and a capacitor sensor was designed to measure the relative permittivity of the icing under the guidance of simulation.The relationship between icing density,relative permittivity,ambient temperature,humidity,wind speed and other parameters is studied by experiments,and the icing density measuring via capacitance measurement is verified.There is a complex non-linear relationship between the icing density and the influence factors during the theoretical and experimental research of this subject,and it is found that the theoretical formula is not accurate in practical measurement.Therefore,after comparing and analyzing the performance of different artificial neural network,the BP neural network is chosen in this paper to build the nonlinear relation model.The calculation model between the icing density and the influence parameters is obtained through the training of sample parameters.And based on the research and sensor technology,the digital icing density sensor which embeds the trained model of icing density calculation is designed and developed,so that it can realize the high-precision on-line measurement of icing density.What's more,the corresponding on-line monitoringdevice for icing density has been developed.The experimental results show that the sensor and the monitoring device can operate safely and stably with high measurement precision.There are 46 figures,12 tables and 74 references in this paper.