Research On Lightning Trip-out Protective Technology Of The Multi-circuit Transmission Lines On The Same Tower

Lightning strike of overhead transmission lines is the main hazard of safe and reliable operation.Zhejiang province belongs to the area with strong lightning activity,lightning strike is one of the most important causes of transmission line fault in Zhejiang power grid.With the increasing intensity of lightning activity,the trip fault of the same tower in Zhejiang is serious,which has a great impact on the stability of the power grid.However,in the actual operation process,multi circuit lines on the same tower has accounted for a large proportion of simultaneous lightning tripping accident of lightning,the transmission capacity of transmission lines on the same tower,the lightning tripping at the same time will cause serious influence on the stability of the system,the lightning flashover rate and simultaneous lightning outage rate limit.In this thesis,the lightning protection measures of the same tower parallel transmission lines are analyzed,and the thesis is divided into 5 parts.Firstly,the background and significance of this study,the research trends at home and abroad,the research contents of this subject are described.Then,the thesis introduces the model of the flashover analysis based on circuit theory,and the mechanism of simultaneous tripping of the same tower multi return line.Then,the thesis introduces the measures of the same tower multi return line lightning strike,analyzes the implementation scheme,advantages and disadvantages of9 kinds of lightning protection measures.In the fourth chapter,with the example of the220 kV power supplier of Wenzhou Electric Power Bureau,the same tower multi return line is taken as an example to carry out the evaluation and implementation scheme of the same kind of anti-lightning and the same hop transformation.Finally,the method to reduce the grounding resistance of the tower and the method of installing the line arrester is selected.Then,the transformation scheme is formulated,and finally the transformation scheme is evaluated.Finally,the paper summarizes the whole paper and prospects the future research.