Research On Lightning Performance And Lightning Protection Measures Of Double-circuit Transmission Lines

Along with our country economy high speed development,load growth in soaring,the shortage of transmission line corridors,grid constantly towards multi loop,large capacity development.lightning is the main form of electric power system fault.Compared with single loop,that problem is particularly serious in the double circuit transmission line.Lightning flashover proportion is higher and higher and lightning trip having serious influence on the economic interests,property safety and stable operation.Studying on lightning performance of double circuit transmission line,the key problem is how to improve lightning level and reduce the possibility of lightning trip at the same time.Performance of double circuit transmission line is integrated closely.Appropriate methods are choosed to set up considering corona coupling capacitance model in ATP-EMTP electromagnetic transient simulation software.Firstly,ZGU115 tower,ZGU215 tower,ZGU315 tower,JU1 tower,JU2 tower,JU3 tower are analyzed in the characteristic of back striking and shielding failure;calculated in different resistance,tower span,dielectric grade,nominal height,tilt angle,striking distance,striking distance factor and other sensitive factors.Double-circuit transmission Tower features trend charts are got.Secondly,21 kinds of lines are analyzed under different phase sequence arrangement,and nine configuration modes of two arresters,ten configuration modes of three arresters,six configuration modes of four arresters with double circuit transmission line lightning resistant characteristics of towers are analyzed.Obtaining the best way to lightning protection.Thirdly,in combination with mountainous landform,insulation configuration and so on,calculating the lightning performance of the overhead and bottom ground coupling line and different height lines.It is can be concluded that the coupling ground vary,the single,double and fourth phase lightning level and tripping rate change is very small,and overall lightning level rising with hanging height.Ground coupling line in most lower level cross arm to improve the effect of lightning resistance is significant.Finally,based on analyzing the various factors influencing lightning level,the different integrated optimization measures in practical engineering are put forward,which has guiding significance for the operation and design of the double-circuit transmission line.