摘要:The article discusses the distribution of the lightning current between communications of the object as the main aspect determining surge protective devices (SPDs) parameters for applying in substation’s low voltage networks. Wireframe model was designed to compute field-circuit model of earthing device (ED) and define the element potentials and currents using circuit analysis methods. Transients were calculated using operator method. Results of calculation and measurements of the lightning current’s distribution in ED and cables in illumination network of air insulated substation presented. Experimental study results obtained in training ground PJSC «Lenenergo», one of the largest electric power distribution company in Russia. Case of lightning strike in the floodlight mast combined с with lightning rod in 110 kV air insulated substation was studied. Requirements for the parameter "impulse discharge current amplitude" SPD defined. Described general approaches to the illumination network’s lightning surge protection on air insulated substation.