Reasons And Simulation Analysis Of The Overheating Of Overhead Line Strain Clamp

In recent years,as many lines have been put into operation for a long time,the overheating problem of the overhead line clamps frequently occurs,which not only greatly restricts the current carrying capacity of the line,but also causes the deformation or even the fuse of the strain clamp when the overheating is severe,and it threatens the safe and reliable operation of transmission lines seriously.Therefore,it is urgent to study the causes and solutions for the overheating of the strain clamp.In view of the overheating problem of tension strain clamp,the main factors of overheating of strain clamp were analyzed through the temperature rise test of strain clamp under multivariate conditions,the mechanism of overheating of tension wire clip was determined,and according to the analysis results,the corresponding measures to prevent overheating of strain clamp and the methods to solve the overheating of strain clamp were proposed.Then,using the three-dimensional finite element tensile clamp simulation model based on electromagnetic-thermal coupling,the temperature field of the strain clamp in different states is simulated,and the temperature distribution of the strain clamp is changed with the contact resistance of different parts.Finally,based on the electro-thermal analogy principle,the maximum temperature calculation model of strain clamp under heavy load is constructed,and the parameters of the model are modified by experiment and simulation results.Finally,a set of software for calculating the maximum temperature of strain clamp is formed.The main findings of this paper are as follows:1.When the current is loaded,the steady-state temperature of the overhead line clamp will increase with the decrease of torque,and also with the increase of contact surface contamination,which has a greater impact on the temperature of the wire clip.When the contact surface is clean,the bolt torque has little influence on the temperature,but when the contact surface is dirty,the increase of bolt torque can significantly reduce the temperature of the wire clamp.2.The clamp can be operated continuously for eight hours at a temperature of about 250℃,but it will aggravate the oxidation of the clamp and may cause serious consequences.3.At the same contact area ratio,the temperature of the drain plate is the highest when it deteriorates,and the influence on the overall temperature of the clamp is the most serious,and the maximum temperature when the contact of the drain plate deteriorates is only 10% lower than the deterioration of all the contact faces.At the same contact area ratio,the temperature at the crimping contact of the clamp body is the lowest,and the temperature of the entire clamp is minimal.4.In actual operation,the temperature difference between the inside and outside of the clamp is small,and the temperature difference does not exceed 5%,so the highest temperature of the surface of the clamp can be used to characterize the internal maximum temperature.5.Due to the structure of the strain clamp,the conductive plate is susceptible to corrosion.At the same time,due to the highest temperature of the same contact surface,the problem of overheating of the drain plate is often caused.At the same time,due to the large crimping structure and the contact surface,when the crimping body of the strain clamp body is severely corroded,the overheating phenomenon may not be obvious.