| As a guaranteed basic project,power transmission is related to the ultimate victory of China comprehensive poverty alleviation.However,due to the vast land and diverse terrains of China,overhead transmission lines are often unavoidable through some repeated ice-covered areas.In addition,since 2008,snow and ice disasters have frequently occurred.,The harm to the power grid is becoming more and more significant,so it is of great significance to study the problem of icing and deicing of overhead transmission lines.In order to obtain a safe deicing strategy,it is necessary to more accurately simulate the dynamic response of transmission line deicing.Based on a 220 k V single-circuit transmission line in Linfen City,Shanxi Province,this thesis carried out a deicing jump test and a numerical simulation study.During the process,it was found that the damping of the ice-coated transmission line is time-varying due to the influence of uneven deicing,and the damping of the ice-coated transmission line is time-varying,and it affects the de-icing of the transmission line.The effect of ice oscillation is obvious.In order to study the influence of the damping change on the jump height of the transmission line during uneven ice removal,a variety of test conditions were designed,and the time history curve of the jump displacement of the transmission line ice removal was obtained.On this basis,the ice thickness and the ice removal rate were discussed.,De-icing position and other factors affect the damping of the ice-coated wire and the simulation accuracy.The results show that the simulation result of ice-off jump without considering the damping change of the ice-coated transmission line is too large,and the result of considering the damping change is closer to the test,which is beneficial to improve the simulation accuracy.The blasting and deicing test of rime and rime type icing was carried out by taking a 50m-long single-span line built outdoors and a 220 k V single-circuit transmission line in Xinzhou City,Shanxi Province as the research objects.Based on the ABAQUS software,a finite element model of the tower-line system is established according to the field tower and transmission line model and span.The different deicing schemes determined by the experiment are used to simulate the dynamic response,and the simulation parameters are corrected by comparing with the field test results.The results show that the simulation results under different types of icing conditions can truly reflect the test results,and the accuracy of the finite element model and simulation method has been better verified.On the basis of the above research,a finite element model of the 6-tower 5-speed tower line system from Pingshun Photovoltaic Boost Station to Pingshun 220 k V line was established.Combined with the design code of this line,the safety of the line during blasting and deicing was analyzed.Aiming at the problem of multiple icing on the transmission line,the deicing ratio to ensure the safety of the tower line system was studied,and the transmission line segmented blasting network was further designed based on the simulation results to verify the feasibility of multiple deicing with one suspension.In the end,the detonating cord laying plan for OPGW optical cable and wire and the deicing plan for two ice-coating blasting and deicing under rime and rime types were determined respectively. |
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