Study On Health Evaluation Of XLPE Cable Based On HDS

With the development of national power grid construction and the implementation of national strategic planning.XLPE cable,as the main carrier of power transmission,plays an increasingly important role in national key projects and urban construction.Therefore,the insulation stability and healthy service life of XLPE cable directly affect the normal life of the broad masses of people and the stable development of economic construction.so,it is necessary to effectively predict the remaining service life of XLPE cable by studying the aging mechanism of XLPE cable and evaluating the cable aging in use.Research at home and abroad shows that under the condition of live work,the insulation layer of cable will be affected by complex external environment such as thermal stress,mechanical stress,environmental stress and so on,which will lead to insulation aging,and ultimately make the cable unable to use normally.The existing insulation aging tests for diagnostic cables are usually divided into destructive tests and non-destructive tests,but most of them are preventive tests sampled before the cables are put into use,which not only consumes a lot of manpower,material and financial resources,but also fails to feed back the aging of cables to the relevant units in the process of using the cables,and there are potential safety hazards.The idea of this paper is to analyze the aging of XLPE cable insulation layer under live condition.Firstly,the basic theory of cable insulation and its electromagnetic theory are deduced and analyzed.Combined with the study of various aging mechanisms,different forms of cable insulation aging under different stresses are obtained,and different forms of high-order harmonics will be produced.Secondly,the harmonic diagnostic system(HDS)is used to collect and process the high-order harmonics in the operation of the cable,and then the comparison and analysis with the expert data system are carried out to effectively get the aging situation of the cable and the possible aging form and location.Then,the remaining service life of the cable with more serious aging is predicted by using the Weibull distribution parameters.Finally,the effectiveness of HDS is verified by two groups of experiments.The first group of tests collects data from 13 10 kV cables in use,extracts 9 valuable cables for analysis,and uses ultra-low frequency dielectric loss method as a comparison test to verify the validity of the results;the second group of tests is two cable lines with potential problems provided by the power supply department are consistent with the results obtained by HDS and the results obtained by the actual line survey.Figure [39] table [10] reference [54]...