Study On The Lightning Trip-out Of Multi-circuit Transmission Lines On The Same Tower

The lightning trip out problems of high voltage transmission line are the main securityrisk the southern area power system in China confronted. With the wide construction ofmulti-circuit transmission lines on the same tower, studies on their new features of lightningtrip out are necessary.This thesis studies the key models of lightning simulation of transmission line based onATP-EMTP and discusses the selection of several key parameters, including the tower model,the insulator string flashover model, the lightning current model, the grounding resistancemodel and transmission line model. Then the proposed models are verified by comparing withthe practical records under actual lightning with obtained lightning currents.In order to overcome the limitations of previous researches which focus on the influenceof single factor, this thesis studied the mechanism of lightning trip out of transmission linesand explained the influencing factors from the principle. Then simulation studies of lightningtrip out is carried out on the220kV double-circuit,110kV four-circuit,220kV four-circuit and110/220kV mixed-four-circuit lines on the same tower. And the protection methods for thetransmission lines could be obtained based on the simulation results obtained.In the end of the thesis, some countermeasures for lightning trip out of transmission lineare put forward based on the sensitive analysis on the factors for lightning trip out of highvoltage transmission line. A routine map of the lightning protection method andtechnical-economic evaluation on the method are also given.