Analysis Of Integrated Lightning Protection On High Voltage Transmission Line

Based on the research results of lightning protection in the transmission lines, this article mainly researches and analyzes the lightning protection and the influence factors of withstanding level in high-voltage transmission lines, this article calculated the lightning withstanding level of transmission lines. Through calculation, this article comprehensively analyzed how to improve lightning protection levels in the power system by effectively reducing the rate of lightning stroke-incidence, and thus to minimize the effect of the lighting striking to the safety running of power system.First, it described the principle of lightning discharge to the transmission line and introduced the forming and development processes of lightning, the forming and developing processes of lightning voltage and lightning current, and the discharge principle under the breakdown of an insulator. It also introduced the application of lightning location system in lightning protection and the lightning main parameters, and finally proposed the main lightning parameters calculation method.This thesis discussed the computational method for calculating the lightning withstanding level, from which the conservational result was obtained. However, conservational result is not suitable for modern power grid, e.g. high tower with stem double lines and large across circuits. This study analyzed the computational problems in detail and introduced the improving in computational method, which used ATP-EMTP and EGM method to calculate the withstand level of the back stroking and the shielding failure.This article discussed the major factors of withstanding level in high-voltage transmission lines, including tower grounding resistance, line spacing, tower height, wire voltage, and tower wave impedance. Moreover, this article also analyzed the principle and the function of the lightning protection including the installation of ground wire , reducing landlines protect horn, reducing tower grounding resistance, the installation of coupling ground wire, improving the coordination of the line, the installation of lightning arresters, the installation of automatic reclosing device, which are usually used in high-voltage transmission lines. The selection of transmission line path pertinently and using lightning protection measurements to reduce the transmission line lightning tripping rate in the lightning protection design of the transmission lines were also discussed.Huizhou region is marked by frequent lightning, and the lightning trip in transmission line is severe .This article analyzed the causes of lightning trip through the trip data and the trip conditions from 220kV and higher voltage transmission lines. Analysis of the factors influencing withstanding level of the back stroking and the shielding failure in high-voltage transmission lines was carried out and the potential lightning protection methods for ensuring the normal operation of high voltage transmission lines and improving the reliability and security of power system were further proposed.At last, the integrated lightning protection adopted in the transmission lines of Huizhou region and the effects were further introduced.