Numerical Simulation Study On The Times Span Vibration Of Overhead Transmission Lines

The times span vibration that wake effects of bundled conductors caused,is the phenomenon of substantial vibration in the vertical direction at a certain wind speed, caused by a mutual interaction of air and wire, is generated complex coupling movement for the wire solid and the flowing gas. Due to their own vibration characteristics of the times span vibration, to many parts of the high-voltage overhead lines, such as wire, spacer and insulators, caused harm that often occur, reduce the reliability and security of high voltage transmission lines. In high voltage transmission lines due to the needs of the installation process as well as security considerations, will improve distance from the install wire to the ground; taking into account of power loss due to corona in the transmission process, Substitute multi-bundled conductors for the single wire in the transmission lines. It is increased distance from the wire to the ground and bundled conductors that meet conditions of the time span vibration, so as to increase the possibility of the times span vibration. For the prevention of the times span vibration, and to ensure the safe and reliable operation of high-voltage transmission lines, it is very necessary to carry out a comprehensive and in-depth research for the times span vibration.Times span vibration is a great deal of threat to the life of the wire, for studying effects the split conductor on the times span vibration, at home and abroad commonly study the times span vibration in using wind tunnel experiments, but because of the wind tunnel experimente quipment is expensive, and long study period, it bring a lot of inconvenience to the research. This article uses the Simulink simulation module of the Matlab software, Simulate the times span vibration, and analyse,it found that the vibration is a the elliptical harmonic vibration, amplitude of harmonic vibration depends on aerodynamic the conductor suffered. In view of this, simulate the air flow field around the wire in using computational fluid dynamics software Fluent, by changing the division gap of the wire,at the same time monitoring and analysis the resistance coefficient and the lift coefficient of the wire, to determine the size of aerodynamic wires suffered, drawn vibration amplitude of the wire, at the last from the analysis of the influence of division gap on the times span vibration of the bundled conductors. The software simulation method not only make up for flaws in studying the times span vibration by wind tunnel experiments, but also provided help for choice of bundled conductors spacer and analysis of the times span vibration. In this paper, the research is the following areas:(1) Analyzed and compared the research of the times span vibration at home and abroad, and found it is less in the domestic research on the times span vibration, but with the increase of high voltage transmission lines, accident of transmission lines caused by the times span vibration is more and more, and become the problem solved urgently in a transmission system, this paper focuses on studying the effects of division gap on the times span vibration in the transmission line.(2) Through visitsing on-site environment,and doing stress analysis on the transmission line, and then establish mechanical equations of high voltage transmission lines, and establish software model in using a Simulink blocks in the Matlab software, establish a software model and simulate in using a common set of data in transmission lines.From analysis of the simulation results, it is concluded that the time span vibration is an elliptical myopia simple harmonic motion, and the amplitude of simple harmonic motion depends on aerodynamic the conductor suffered. This conclusion provides a theoretical basis for the analysis of effects division gap of bundled conductors on the times span vibration.(3) Using Gambit software establish the times span vibration model of bundled conductors,and meshing to prepare for simulation of Fluent software, modeling and simulate the times file vibration in using a software Fluent in the hydrodynamics, draw law of effects of division gap on the times span vibration in high-voltage transmission lines.(4) By analysis of simulation results of Fluent software, it conclude that simulation results and the results of wind tunnel experiments is same, this result suggests that method waht is simulating the times span vibration by the software is feasible and can be used in combination with wind tunnel experiments to analyze the times span vibration.