Modeling On Transmission Tower-line System And Simulation Research On The Jumping Of Transmission Line After Ice-shedding

As the lifeline engineering of national economy construction, high-voltage transmission tower-line’s normal running provides the guarantee for state economy development and people’s lives and property. Long span and tall-flexible transmission line presents obvious nonlinear vibration property during the vibration, especially more complex in the course of ice and deice. Due to the impact of dynamic ice unloading, the accident such as the broken transmission line and collapsed transmission tower may happen, causing a great economic loss. Therefore, this paper intensively studies the coupled vibrations property of overhead transmission line and dynamic response property caused by icing and deicing. The finished work as follows:In the consideration of effect of geometry nonlinear transmission line, the nonlinear vibration kinetics equation about two-span transmission line possessed with oblique angle and the coupled vibration of insulator string. Then, in the use of numerical software, the vibration response is solved under different circumstances. On the basis of displacement time-history curve, the characteristics which involved in two-span transmission line nonlinear coupled vibration and internal resonance were obtained. The paper gives some conclusions by analyzing inclined angle.On the background of one 220 KV transmission line in Hunan province, the finite element analysis model about three-tower and two-span system is built. By taking geometric nonlinearity effect into account, aiming at line’s tension of pay-off and using Newton Laphson iteration calculation makes sure the initial structure of transmission line. The initial structure’s mid-span sag is accurately consistent with theoretical value. In the use of the technique of birth and death of element to simulate deice impact load, we make an analysis of transient time-history in different dynamic response to whole spans’ ice unloading and zippered ice unloading, acquiring some significant parameter values such as maximum jump height and amplitude and new balance location.According to the dynamic similarity theory,designed a test model of three-tower and two-span system. By means of adopting finite element method,made some numerical emulation research of dynamic response under different ice unloading test conditions. And then by comparing to prototype result, we can find that maximum jump height.amplitude and new balance location fit in well with the requirement of dynamic similarity. It is concluded that the dynamic similarity design of test model is accurate and the mutual test results can be derived from each other. In the meantime, the results in this paper provide a theoretical guidance for next test modeling, the design of measurement system and deicing test.