On The Analysis Of Mechanical Performance Of Uhv Short Conductor Considering Stiffness Effect

With the rapid development of China’s national economy,the country’s demand for energy is growing day by day.As the world’s leading power transmission technology,UHV power transmission technology was written into the outline of the 14 th Five-year Plan in March 2020 as one of the seven fields of "new infrastructure".Although UHV transmission technology has advantages that traditional transmission technology cannot compete with,as an emerging technology,it still has many unresolved technical problems.Among them,there has been no systematic research on the mechanical performance of the short wires in UHV substation when considering the stiffness effect.Conductors are often regarded as members without bending stiffness in engineering calculations.However,it has been proved that ignoring the stiffness effect of conductors will bring unacceptable errors to engineering calculations and even lead to insulation accidents.The wires in the actual project are connected to other ground equipment or structures through terminal equipment such as terminal clamps and terminal plates.Here,this paper aims to analyze the mechanical performance of UHV short wire and its connected terminal equipment with consideration of the stiffness effect,and to propose empirical formulas for engineering calculation,and give some suggestions for engineering design reference according to the research results.In order to take into account the effect of stiffness of short wire and the convergence of numerical model,a simplified finite element model of short wire is designed in this paper,which takes into account the characteristics of large axial stiffness of short wire and small lateral stiffness.It is verified that the results of the simplified model differ little from the experimental results,which can meet the needs of engineering calculation and scientific research.In this paper,a simplified finite element model of short wire is used to analyze the mechanical properties of equal-height wires and unequal height difference wires.The main difference between equal-height difference wire and unequal height difference wire is whether there is symmetry in space.At the same time,unequal height difference wire involves the selection of terminal clamps.In this paper,the formulas for calculating the end force of the wire in the connection of equal height difference and unequal height difference are obtained through calculation and fitting,and the design suggestions are given.Considering that the site of failure in practical engineering often appears at the terminal equipment,combined with the research results of the wire’s mechanical performance,this paper conducts numerical simulation of the terminal equipment.The results show that the terminal equipment has yielded under bolt preloading and stress concentration occurs under external load.The bearing capacity of terminal equipment varies greatly in different directions.By analyzing the mechanical properties of UHV short wire and the terminal equipment,this paper finds out the shortcomings of the original calculation formula,and the research results can provide data reference for engineering calculation,which fills in the research gap in this field.