Research On Lightning Protection And Break-off Measures In 10kV Distribution Network

The 10 kV distribution line has large power supply coverage and the total line length is amazing.Most of the lines are in the form of overhead lines,and rarely set up lightning lines,so the probability of being struck by lightning is large.Especially in thunderstorm weather,when lightning strikes,it will cause trip,damage equipment,threaten the safety of power system,and affect daily work and life.In this paper,the lightning protection measures of 10 kV distribution network are analyzed and fuzzy comprehensive evaluation is made,and the lightning protection measures are optimized.Firstly,the mechanism of lightning wire breaking is analyzed from the perspective of electromagnetic field and mechanics,and the characteristics of lightning wire breaking fault are studied,and the causes of lightning wire breaking are analyzed in depth;the calculation method and process of induced overvoltage in 10 kV distribution network are mainly elaborated,including the development process of lightning current,electromagnetic field in lightning channel in pilot process,electromagnetic field in lightning channel in return stroke process and overhead line.The calculation process of lightning induced voltage.Secondly,the paper introduces the basic situation of lightning protection of distribution network lines,analyzes the characteristics of lightning trip of distribution network lines,focuses on the differential analysis of lightning protection measures for 10 kV distribution network,and gives the conclusion for six different lightning protection measures.Thirdly,it analyzes the comprehensive evaluation methods,including analytic hierarchy process(AHP)and fuzzy comprehensive evaluation method and their steps;expounds the establishment process of evaluation index system for lightning protection measures of 10 kV distribution network,including the establishment principle and evaluation index system of evaluation index,and then expounds the determination process of comprehensive evaluation index weight,including the establishment of evaluation standard and method selection,index weight survey data Statistical analysis and the calculation process of index weight;the lightning protection measures of 10 kV distribution network are evaluated by the first and second level fuzzy comprehensive evaluation,and the comparison of lightning protection measures effect is obtained.The order from high to low is: differential insulation,installation of lightning protection gap,erection of coupling ground wire,reduction of tower grounding resistance,installation of lightning arrester.Forthly,combined with the results of differentiation analysis and comprehensive evaluation,the lightning protection measures of 10 kV distribution network are optimized,including reasonable use of line arresters,reduction of grounding impedance of towers with lightning conductor,erection of coupling ground wire in vulnerable section,erection of lightning conductor to improve line grounding mode,optimization of neutral point grounding mode,and elimination of line insulation weakness.Finally,this paper analyzes and studies the lightning protection measures of 10 kV distribution line,compares the differences,finds out the advantages and disadvantages of various measures,and puts forward suggestions for improvement.At the same time,the influence of fault trip and induced overvoltage on power system is studied,and an evaluation system of lightning protection measures is given.At present,this type of lightning arrester has been widely promoted and applied in Changzhou,which is conducive to better meet the requirements of lightning protection and further improve the reliability of power supply.