A Preliminary Study On The Strand Stress Of Transmission Line In Tension Stringing

China’s vast geographical and economic development determines the uneven distribution of energy and power load,which makes long-distance power transmission an inevitable choice.In order to ensure the safe operation of power grid,we should pay attention to the reliability of transmission lines.However,the transmission line often suffers from conductor damage during operation,most of which is caused by excessive local stress of aluminum strand.However,tension paying off pulley may also be one of the causes of conductor damage.At the same time,there is relatively little research on conductor damage caused by pulley.Therefore,it is very important to study the inter strand stress characteristics of aluminum strand when the conductor passes pulley.Under this background,this paper studies the inter strand stress characteristics of aluminum strand when tension paying off passes the pulley.When considering the stress of ACSR in bending state,the conductor model is constructed in two steps,that is,the same layer strand model and the adjacent layer strand model.Then through numerical simulation,the influence of envelope angle,tension load and friction on the inter strand stress of aluminum strand is studied.Then,based on the test platform,the test and Simulation of the conductor passing through the pulley are carried out,and the inter strand stress characteristics of the conductor in the bending state are studied,and the same layer strand model is preliminarily verified.The main achievements of this paper are as follows:(1)The complex inter strand stress problem is divided into two steps to study,and the same ply model and the adjacent ply model are proposed.The results of numerical simulation are in good agreement with the corresponding research results,which verify the correctness and rationality of the model.(2)Taking an ACSR as the research object,through numerical simulation,the stress characteristics of aluminum strand under different envelope angle,different tension load and different friction conditions are studied when ACSR passes through the pulley.The results show that the section stress of the aluminum strand decreases gradually from the edge position to the neutral layer,and the maximum equivalent stress appears in the contact position of the adjacent strand.The greater the envelope angle and the tension load,the greater the section stress of the aluminum strand.At the same time,compared with the envelope angle,the effect of the tension load on the aluminum strand is smaller.Compared with no friction,the stress value of aluminum strands decreases.so the friction between aluminum strands can reduce the section stress.The equivalent stress of the aluminum strand increases from the outer layer to the inner layer,so the inner aluminum strand is more likely to be damaged than the outer layer.(3)Based on the test platform,the test and simulation are carried out respectively,and the stress characteristics of aluminum strand under bending state when the conductor passes the pulley are further studied.After comparing the two results,the overall error is within the acceptable range,and the stress value of the corresponding section shows good consistency.