| The lighting problems are common and dangerous to extra high-voltage (EHV) transmission systems. To improve unit-lighting performance of transmission equipments, decrease tripping probability, improve power supply reliability, effectively enhance lighting assessment and protection capability for the transmission lines, and economically design and reconfigure the lighting protection facilities of transmission lines, based on lighting flashover risk assessment, lighting protection measures, and long-term lighting record data, lighting distribution along the transmission corridor of EHV lines are stated and analyzed. Difference of line characterized parameters, historical lighting hazard, calculation models of lighting protection, anti-lighting measures, and technology and economics are compared, based on which the security and unit-lighting capability of the towers are quantified, thus to determine the risk level and lighting withstand level. The differential anti-lighting schemes for the EHV/UHV lines are proposed. The differential anti-lighting assessment system is derived. The lighting distribution map of Anhui electrical power systems, i.e. grounding flashover density, shielding failure, back stroke, are drawn, proving reference for active lighting protection based on lighting record data for Anhui power grid. The500kV Guanli5365and Shanli5366lines in2012are taken as example to assess flashover risk and differential anti-lighting measures. The detailed lighting protection schemes are proposed for the lines to effectively avoid lighting flashover, while maintaining economics. |
