Study On The Differentiation Strategy Of Lightning Protection Of220kV Shangshun/Shangao Transmission Line

Research on differentiation strategy of lightning protection is the basis oftransmission line’s scientific lightning protection design, which can provide powerfulmeans for comprehensive assessment of transmission line’s lightning protectionperformance and find the weak link of transmission line’s lightning protectionperformance. The lightning risk of transmission line is closely related to the lightningactivities in line corridors, meanwhile, the influence of transmission line’s concretestructural parameters and differences of line corridor’s landform on transmission line’slightning protection performance can’t be ignored. Taking a220kV double-circuittransmission line as an example, which faces not only the risk of single circuit’slightning strip-out, but also consider the damage caused by double circuits’ lightningstrip-out strictly. Different lightning protection measures have specific scope andimplementation costs, in the context of considering the difference of different linesections’ lighting problems, research on lightning protection strategy and relatedtechnical measures and implementation system played a vital role in lightningprotection technology measures’ layout design. Therefore, considered the influence ofthe differences of the multi-factors range from thunderbolt character to transmissionline’s concrete structural parameters, transmission line’s differentiation strategy oflightning flashover risk assessment and method of lightning protection measures’collocation method should be applied to transmission line’s lightning protectionresearch.First of all this paper studies the shielding failure lightning protection performanceof the transmission line in complex terrain areas, aiming at solving the problem oflacking of line corridor’s geomorphologic parameters, writes MFC program to obtainthe coordinate parameters of the target area with Google Earth, presentsthree-dimensional EGM method for transmission line in complex terrain areas. Thentwo500kV transmission lines in complex terrain area are taken as examples, thecalculation results are compared with that of different methods, this paper also analysesthe influence of different factors on the shielding failure lightning protectionperformance of the transmission line in complex terrain areas.Then this paper studies the back striking lightning protection performance of thetransmission line in complex terrain areas, builds back flashover analysis model considering the differences of towers. For the reason that the lightning current ofshielding failure is smaller, So it cannot lead to the double circuits’ lightning strip-out.And based on the transmission line’s operating experience, double circuits’ lightningstrip-out accidents are mostly caused by back striking. Based on the back flashoveranalysis model set up by PSCAD software, this paper analyzes the tower’s potentialdistribution in the whole lightning process, meanwhile analyzes the insulators’ flashoverprocess in single circuit’s lightning strip-out accident and double circuits’ lightningstrip-out accident, as well as the influence of different factors on the back strikinglightning protection performance.Finally, considering line corridors lightning activity characteristics, tower’sconcrete structural parameters, etc, this paper studies transmission line’s differentiationstrategy of lightning protection, makes the lightning protection performance evaluationusing the methods mentioned above, based on lightning ground flash densitydistribution. The focus of different transmission lines’ lightning protection are notsimilar to each other, this paper mainly conduct researches on the double circuits’lightning strip-out, so in the end this paper proposes transmission line’s differentiationstrategy of lightning protection measures’ collocation method, and analyses theinfluence of different lightning protection measures on the transmission lines’ lightningprotection performance, also makes a reform project of differentiation strategy of a220kV double-circuit transmission line.Above all, this method results in the development of lightning protectiontechnology, also optimizes the line’s lightning protection design in complex terrain areas,and achieves the goal of reducing transmission line’s lightning flashover accident andimproves the line’s operation economical efficiency, thus to possess applicable value inengineering.