Research On Lightning Strike Location And Identification Of 110kV Double-circuit Lines On The Same Tower

With the continuous development of power grid construction,people's demand for power supply reliability is also increasing.Lightning strikes have always been one of the major threats to the safe operation of transmission systems.The 110 kV system line accounted for a relatively high proportion,the complex line situation is complex,and there are often more frequent lightning strikes.And in order to save the line corridor space,increase the transmission capacity of the line and use the double-circuit transmission line on the same tower,and the same tower line on the project is mostly part of the same tower line.However,the study of 110 kV partial double-circuit lines on the same tower is very scarce nowadays.With the 110 kV part of double-circuit line on the same tower being used more and more widely in 110 kV systems,it is urgent to conduct detailed analysis on this line type.110kV partial double-circuit line on the same tower,which is divided into single-circuit lines at the sub-tower and connected to different systems.There are not only phase-to-phase coupling but also line-to-line coupling at the double-circuit line type.In this paper,it was found through research that the two lines are usually separated at a relatively small angle at the sub-tower,which makes the coupling between the lines from the double loop to the single-loop gradually weakened,forming a gradual process,which makes the analysis of the line Coupling is more complicated.Therefore,by using PSCAD/EMTDC to establish a 110 kV partial double-circuit line model on the same tower,this paper deeply analyzes the traveling wave propagation process and the coupling between lines,and concludes that the fault traveling wave and the line coupling traveling wave on the 110 kV partial double-circuit line on the same tower have Clearly different propagation paths.Due to the influence of the coupled current traveling wave,the polarity of the zero-mode current wave head at each measurement end of the 110 kV partial double-circuit line on the same tower has certain characteristics.Based on this,based on the characteristics of the polarity of the zero-mode current wave head at each measurement end,this section is used to locate the lightning strike zone,and the fault line selection technology and the lightning fault location technology are further analyzed.Based on the research,it was further found that regardless of whether a single-loop loopback or counterattack occurred on a 110 kV double-circuit line on the same tower,they all had similar waveform characteristics with the bypass loop at the double-circuit line.This gave a unified identification of the bypass and counterattack.Must be affected.Therefore,in this paper,the flashover and non-flashover,bypass and counterattack of the line are analyzed based on the location of the lightning strike fault zone.Finally,according to the line propagation characteristics of the line type and the zero-mode current waveform characteristics of the flashover,a utilization is obtained.The Method of Flashover and Unflashover Identification for 110 kV Partial Double-circuit Transmission Lines with Straight Line Fittings.Based on this,the identification methods for the bypass and counterattack at the double-circuit line under the conditions of flashover and non-flashover are studied respectively.