Theory And Research Of Remaining Life Prediction Of XLPE And EPR Cables

With the rapid development of science and technology,people's living standards are constantly im proving,and the importance of electric energy to people is increasing.Work,entertainment,production,and life are inseparable from electricity.As the main tool for transmitting electrical energy and electrical signals,the cable ensures that its normal operation is the prerequisite for ensuring the quality of life.And when the cable fails,it can easily cause fire.A large part of the fires that occur in our country each year are electric fires.The number of fires caused by short-circuits in electrical fires is also enormous.There are many causes of cable aging,of which the most significant one is thermal aging.Especially in recent years,cables often run overloaded during peak hours.The inside of the cable will generate huge heat,which will aggravate the effect of heat aging and make the service life of the cable seriously reduced.It can easily cause fire and cause economic and personnel damage.Regular cable replacement is a good way to solve this problem.But replacing the cable is also a complicated and expensive method.Therefore,how to accurately predict the remaining cable life and more scientifically replace the cable is the purpose of this study.This article mainly studies the effect of heat aging on the cable life,analyzes the remaining life of the cable in a variety of ways,establishes the cable remaining life model,and more scientifically predicts the remaining life of the cable and avoids blindly replacing the cable.The main work of this article is as follows:First of all,according to national standards,conducting thermal aging tests on XLPE cables and EPR cables and aging time exceeds 2500 hours.520 aging samples of XLPE cables and 200 aging samples of EPR cables were obtained.Tensile experiments were performed on the samples and a total of 720 experimental data were obtained.Second,this article describes the common cable insulation aging life model.And this article describes the theory of various models,derivation process,advantages and disadvantages,etc.The main research direction of this paper is the aging effect of thermal influencing factors on cable insulation.Third,describing the advantages of second-order kinetic models over first-order kinetic models.Determine the aging rate is not constant.Moreover,an improved model based on the second order dynamic model and TTSP for cable thermal lifespan prediction was proposed,and verify the correctness of this model.Simplify the fitting function in this model process.Feasibility analysis was conducted using the experimental data of the ethylene-propylene cable sample.Finally,descriptive multiple nonlinear regression analysis.And use this method to analyze the experimental data of XLPE samples.Using EViews analysis software to fit the experimental data.Fitting function using two deformation equations of Arrhenius equation.Analyzing the goodness of fit to determine the rationality of the two cable residual life prediction models obtained by the two fitting methods.Selecting the cable residual life prediction modelwith a higher degree of fit to calculate the service life of the cable at room temperature.Using this calculation result to compare with the label of the cable factory.Then according to the comparison results further analysis of its rationality.