Study On Maximum Allowable Carrying Capacity Of Overhead Transmission Lines Under High Wind Speed

China has a vast territory and different climates in different regions.The high wind speed is good for the heat dissipation of the wire and reduces the operating temperature.In the high wind speed environment condition that the annual average wind speed is greater than 6.0m/s,the more conservative boundary conditions are still used to determine the limit of the current carrying capacity of the wire,which limits the effective utilization of the carrying capacity of the wire.Studying the calculation model of carrying capacity that is suitable for high wind speed environment has a positive significance for excavating the potential current carrying capacity of the release wire.Aiming at the problem that the calculation value of the wire carrying capacity model in the existing national standard is too conservative under the high wind speed environment,a calculation model of the wire current carrying capacity coupled with the aerodynamic equation and the thermodynamic equation is proposed to improve the accuracy of the ampacity calculation from the model level.At the same time,a wire temperature rise test method and device are designed,and the proposed model is verified by simulation calculation and test data.The main research work of the thesis is:(1)Several typical ampacity calculation models in domestic and international standards are analyzed.The influence of the selection of boundary conditions on the current-carrying calculation and the influence of the values of various important parameters on the calculation results are analyzed.It provides a theoretical basis for improving the current conservative boundary conditions and increasing the carrying capacity of the wires.(2)A detailed analysis of the calculation formulas in the IEEE and CIGRE models is carried out to derive the sub-formula for the current-carrying calculation in the national standard.It explains the formation process of the simplified calculation formula,the possible changes of the relevant parameters in the simplified formula and the influence of the parameter changes on the calculation results,which provides a basis for the improvement of the formula.(3)For the determination of the carrying capacity of the wire at high wind speed,a finite element calculation model of the coupled aerodynamic equation and the thermodynamic equation is proposed,which solves the problem that the current carrying capacity calculation method is not suitable for the large wind speed environment.(4)A uniform wind speed generation device based on finite element method structure optimization is proposed.The temperature rise test platform is built.The test method,simulation calculation results and wind speed sensitivity test analysis of large section conductors are given.The test data is combined with the test data to verify the proposed Improve the accuracy of the ampacity calculation model and its applicability to large-section conductors.