Study On Response Of Transmission Tower-line System Under Complicated Loads

In recent years,with impressive growth of economy in China,the demand of electric power has dramatically increased,and electric energy has become absolutely necessary in our daily life.Power transmission tower plays an increasingly important role in the process of power transmission.The destruction of transmission towers or wires in transmission lines will lead to the interruption of power transmission.This not only affects people's daily production and life,or what's worse,holds back the economic development,but also will cause serious secondary disasters to the people.Therefore,ensuring the safety of transmission lines has become an important issue that can't be ignored.In general,it often seems to think of tower and lines separately rather than coupling system in the world of designing.At the same time,due to the large span and high flexibility of transmission tower-line system,it often results in/causes severe vibration and even damage in various weather conditions and complex environments.In view of the above problems,this paper aims to build numerical models of transmission tower-line system to detect the dynamic characteristics of the tower-line system and the excitation response under different conditions.This paper firstly introduces the numerical simulation theory of wind load and completes the wind speed time history simulation by the harmonic synthesis method.Then it attempts to build finite element models of transmission line system by ANSYS software and verifies the correctness of the model by modal analysis and it also compares the effects of wire and model type on the dynamic characteristics of transmission towerline system.Under the dynamic time history analysis,a simplified transmission towerline system model is proposed.On this basis,the dynamic response of the simplified model under several complicated conditions such as different typhoon spectras,wind-rain induce and the wind field of the mountain is studied.Through the research,it turns out that the model of one-tower-two-line tower-line system with enough accuracy can be used as a practical engineering model.Under different landform types and wind conditions,the response of transmission tower-line system varies widely and it should be designed separately according to the needs.Besides,the effect of heavy rainfall on transmission tower-line system cannot be neglected,and the pulsation of rainfall should be taken into consideration properly.On the other hand,the transmission line also should be erected to avoid the area with large acceleration effect due to its great influence on the dynamic response of the tower line system.