Effect of lightning return stroke current parameter’s on the components of lightning generated vertical electric field over finitely conducting earth

The scope of this paper is to investigate the effects of lightning induced return stroke current parameters such as peak value, velocity of propagation and cloud height, and the distance of observation point from lightning strike point on the electrostatic, induction and radiation components of lightning generated vertical electric field in time domain. Modified dipole technique has been used in this paper to perform these investigations on and above the finitely conducting earthpsilas surface. The use of modified dipole technique has overcome the limitations of conventionally used Sommerfeld integral and wave-tilt function methods for lightning induced field analyses. It has been observed that all the components of vertical electric field are highly affected by the peak value of lightning induced return stroke current and the distance of observation point from lightning strike point. The effects of velocity of propagation of lightning current on the electrostatic and radiation components are greater than that of induction component. The radiation component is not affected by the cloud height.