Prediction And Experimental Study On Ice Thickness Of Overhead Transmission Line Based On Dynamic Tension And Angle

Accidents such as break line and tower collapse caused by heavy icing bring greatthreat to safety and stability performance of the power systems. Prediction model oficing for transmission lines is hot spot of domestic and foreign research, and manytheoretical results have been achieved. However, existing prediction models overlookunequal loading due to strain insulator string as well as increase of combined loadcaused by wind force. Accuracy of these models is also doubtable due to shortage offield test. Therefore the purpose of this paper is to present a new prediction model oftransmission line icing, and to verify its accuracy by experimental study.Based on study of mechanical calculation theory of transmission line, a newprediction model taking axial tension and angle as parameters is established in thispaper. Experimental study is carried out in natural icing experiment station for modelverification. Based on field test experience, a new ice thickness manual measure methodusing correct factor of ice shape is presented. Signal of transmission line parameters iscollected by sensors. Analysis and comparison on icing thickness results of field testand model calculation after signal de-niosing can verify accuracy of this model.Through experimental investigation and software calculation, followingconclusions are obtained.This model considers unequal loading due to strain insulator string as well asincrease of combined load caused by wind force. Combined load equivalent icethickness is slightly higher than equivalent ice thickness obtained by field measurement.The error is in the allowable range, thus accuracy of this model is verified.As for the dynamic signal, use Fast Fourier Transform for the first filer process,and wavelet threshold method for the second de-noising process. Comprehensiveutilization of these two methods can accomplish the de-noising process of dynamicsignal.The new ice thickness manual measure method using correct factor of ice shapemakes field icing measurement more precise and more convenient.