Broken Wire Analysis Of Transmission Line Systems

Transmission line is an important project, which plays an important role in Chinese economical construction. Based on the large span transmission tower project, the paper, using finite element method, makes a detailed research on the impact load from the broken wire, under four wire-broken condition(break one sub-wire, break two sub-wire, break three sub-wire, break four sub-wire), for four splitting a wire in the large span transmission tower, and also analysed the impact load from the broken wire, under the condition of having interface and having no interface. Finally, based on the normal transmission line system, the paper discusses the impact load to the transmission tower from the broken wire, when the distance or strain changes.Firstly, the general situation of the transmission towers is introduced, and the dynamic properties and the broken wire research status quo of the transmission towers are also introduced. The FEM model of transmission towers is established, the dynamic properties of the single tower and the conductor and the transmission towers are analysed.Secondly, the accuracy of the large-span transmission system under the self-weight load condition is checked. The process of conductor fracture and fall is simulated. The paper calculates the conductor breakage impact load and the impact coefficient under the working condition of breaking one sub-conductor or breaking two sub-conductors or breaking three sub-conductors or breaking four sub-conductors. From the results of the model analysis, we can know that the impact effect on the tower head and tower neck is relatively serious.Then, under the working condition of considering the ground, the process of conductor fracture and fall and contact with the ground is simulated. The conductor breakage impact load and the impact coefficient under the working condition of breaking one sub-conductor or breaking two sub-conductors or breaking three sub-conductors or breaking four sub-conductors is calculated when considering the contact with the ground. By comparing the impact load and the impact coefficient under the condition of having the ground and having no the ground, the paper find that there are two bigger impact process during the breakage conductor condition, one is the impact from the transient of the conductor fracture, the other is the impact from collision transient between the dropping conductor and the ground.Finally, The FEM model of the normal transmission towers is established. The paper studies the impact action to the tower from the breakage conductor when the distance or strain changes, and also compares bar axial stress in the tower during the breakage conductor process.