Study On Seismic Response And Vulnerability Of Floating Power Distribution Cabinet

In high-intensity earthquake areas,earthquakes are an important factor that seriously threatens the safe operation of substations.If a substation,which is a key facility for energy supply,is damaged in an earthquake,it will lead to power supply interruptions,hindering earthquake relief and post-disaster reconstruction.As an important electrical equipment in substations,power distribution cabinets are often damaged by slippage or overturning in earthquakes.Therefore,it is of great social significance and economic benefits to study the dynamic response of the floating distribution cabinet of substation and effectively improve its seismic performance.In this paper,the seismic performance of floating distribution cabinets is carried out,the motion law of floating power distribution cabinets under different excitations is explored,effective seismic measures are taken to improve the seismic performance of floating power distribution cabinets,and the overturning probability of power distribution cabinets is evaluated.The main work and conclusions of this paper are as follows:(1)The motion law of floating power distribution cabinet under different simple harmonic excitations(single sine wave,single cosine wave and continuous loading of two cosine waves)was studied;The vibration table scale model experiment and numerical calculation results were verified.The effect of improving the seismic ability of the vertical spring connected to the bottom of the floating power distribution cabinet was analyzed,and the spring rate and pretension force were parametrically analyzed.The results show that under the action of three simple harmonic excitations,the collision overturning area gradually shrinks with the increase of the aspect ratio of the distribution cabinet model.Under the excitation of a single cosine wave and two continuous cosine waves,the frequency of floating distribution cabinet overturning was mainly concentrated in the range ofω_g/p≤4.Increasing the stiffness of the connecting spring and applying a larger pre-tension force can improve the overturning resistance of the model,which is more stable.(2)The seismic response under seismic wave excitation in the floating state and the vertical spring distribution cabinet was numerically calculated;Taking PGA,PGV and other commonly used ground motion strength indicators as variables,the failure probability of overturning of the distribution cabinet model was calculated by three methods:incremental dynamic analysis,logistic regression and BP neural network.The results show that when the ground motion indicators HI and PGV are used as variables,logistic regression and BP neural network methods can accurately calculate the failure probability of model overturning,and compared with the power distribution cabinet in the floating state,the vertical spring connected to the bottom center can effectively reduce the failure probability of the power distribution cabinet overturning.(3)The heatmap value corresponding to the seismic wave excitation when the model overturns is calculated by the Grad-CAM interpretability method,so as to obtain the heat map,and gradually extract the feature parameters from it,form a new vector IM as a variable,calculate the failure probability of the distribution cabinet overturn by logistic regression and BP neural network method,and compare it with PGA as a variable.The results show that compared with univariate PGA as the variable,vector IM as the variable can calculate the failure probability of the distribution cabinet overturning more accurately,and obtain the vulnerability curve of the model when it overturns.