Model Selection And Optimization Analysis Of 750kV Lattice Substation Framework

Energy producing area and electricity load area are unevenly distributed in our country,eastern coastal areas and southern areas where primary energy is short and power load is concentrated face electrical power shortage,so the facilities construction of high voltage,large capacity and long distance transmission has led a tengency for social developmengt under the energy configuration’s basic national policy of“West-East Electricity Transmission Project” and “North-South Electricity Transmission Project”.The section selection and optimization analysis have important sence to structural safety and engineering cost in substation frame as an important component of power transmission and transformation project,but the systematic research of lattice substation framework is deficient in the literatures at home and abroad.According to the proposed 750 k V transformer substation in the Mulei region of Xinjiang,lattice substation framework has been analyzed by finite element analysis software SAP2000 in many aspects,the main contents and achievements of this paper are as follows:(1)36 root span types of lattice substation framework has been analyzed by finite element analysis software SAP2000 under the condition of limit states of ultimate bearing capacity and limit states of serviceability,getting the sectional selection of all root span types and contrasting the deformation,internal force and steel consumption,studies have show that the optimal root span of lattice substation framework is9.0m×4.0m,lattice structure’s cost drives down 24.4% and 2.4% when compared with pure steel pipe herringbone column structure and concrete-filled steel pipe herringbone column structure,it has notable economic efficiency considered with engineering cost and convenience.of steel structure’s installation.(2)The temperature’s effect on the 4-span substation framework and long framework which longitudinal temperature section ranges between 150 meters to 600 meters by increasing spans have been analyzed based on the optimal root span.It shows that combination of loads included temperature must be considered in the design,the temperature will control the load of framework when wind pressure is weak,and the temperature joint can be cancelled in the long framework.(3)The application of high-sterngth steel in the lattice substation framework has been researched by the use of high-sterngth steel in column’s main rod,such as Q390,Q420,Q460,Q500,Q550 and Q690.It suggests that applicating the Q420high-sterngth steel hasn’t obvious economic performance reducing 1.25% in the cost of framework’s steel consumption considered with requirements for seismic structural measures in the Mulei region;In non-seismic checking area,there has some economic performance when applicating the Q460 high-sterngth steel reducing 7.88% in the cost of steel consumption.(4)The change of earthquake intensity effect on lattice substation framework has been contrasted under the frequent earthquakes and rare earthquakes,meantime,wind pressure’s effect on the deformation and internal force has been analyzed.It indicates that it can ignore the influence of frequent earthquake but it must consider rare earthquakes in practical engineering of substation framework and wind load has a marked impact on the deformation,internal force and steel consumption.