Optimized design of earthing network with power frequency earthing resistance substituted by effective utilization ratio of earthing network area in the event of lightning strike

The result of this study has indicated explicitly that the power frequency earthing resistance value could not be taken as the benchmark to judge the qualification of the lightning protection earthing system, and it has corrected the practice implemented by people over several decades to decrease the lightning damage only by lowering the power frequency earthing resistance value; and the study has proposed an optimized design of earthing network in which the effective area of lightning dissipation is used to substitute the power frequency earthing resistance value, to make the earthing network more simplified and effective. The invention has been included in the Code for Design of Lightning Protection and Earthing Engineering for Telecommunication Stations/Sites GB50689-2011 listed in national standards, the Code for Design of Lightning Protection and Earthing Engineering for Telecommunication Stations/Sites YD5098-2005 as for the telecommunication industry of China, and the Technical Specification and Test Method for Lightning Protection of Radio Base Station, and it has been extensively applied in the base stations of China Unicom since 2006. The base station construction cost has been cut down by more than RMB 3 billion in total under the premise that the safety level of lightning protection in the base station is guaranteed.