Experimental investigation of electromagnetic wave propagation on a substation grounding system

Experimental investigations of the propagation of electromagnetic waves in the grounding wire were carried out at the operating 150 kV substation. The wave propagation velocities obtained during the experiment are in the range of 50–100·106 m/s. Thus, the obtained wave propagation velocity along the grounding grid of the substation is several times less than the speed of light, which can radically change the design approaches of the grounding in term of lightning protection.