Research Of Anti-icing Lightning Protection Methods For The Transmission Line Heavily Icing Region

For the transmission line heavily icing, lightning shielding wires play a lightning protection effect at the same time, due to the icing sagging serious, discharge between lightning shielding wires and phase conductors as a result of uneven ice shedding and vibration, this condition is often accompanied by tripping accidents, it is necessary to study anti-icing lightning protection methods for the line renovation. In this dissertation, for the transmission line heavily icing region, application PSCAD/EMTDC electromagnetic transient simulation platform to build fine line lightning electromagnetic transient model, with double lightning shielding wires directly to ground, and double lightning shielding wires insulation reconstruction (DC ice melting reconstruction), then simulation calculation lightning withstand levels of the line for two different anti-icing lightning protection methods, put forward the renovation plans of lightning protection and anti-icing for the transmission line. The main research work is summarized as following:(1) Analysis and comparison of the transmission line icing formation mechanism as well as anti-icing methods in engineering practice, and overviews analytical focus of the DC ice melting technology. Presented lightning discharge and lightning strike accidents formation process, and the harm of the lightning strike on the safe operation of the power system transmission line, analysis of the main measures to prevent overvoltage of the transmission line.(2) Analysis of the transmission line operation with double lightning shielding wires due to heavy icing and the existence of the hidden dangers. According to the actual operation conditions of the line, comprehensive comparison of lightning protection methods for the transmission line, put forward the initial plans for improving lightning protection of the transmission ine.(3) The theoretical derivation lightning withstand levels of transmission line with double lightning shielding wires, single coupling ground wire, single lightning shielding wire and single coupling ground wire when lightning strikes the tower.(4) Application electromagnetic transient simulation software PSCAD/EMTDC, build the line with double lightning shielding wires directly to ground, DC ice melting after reconstruction (double lightning shielding wires insulation reconstruction), single lightning shielding wire and single coupling ground wire, single coupling ground wire, double side shielding ground wires, the fine electromagnetic transient model of these five different anti-icing lightning protection methods, simulation calculation lightning strikes at the top of the tower and mid-span line, then comparison of the line lightning withstand levels, analysis of the reasonableness for the preliminary modification scheme. Finally, put forward plans to improve anti-icing lightning protection for the transmission line heavily icing region.