The Lightning Induced Over-Voltage (LIOV) code

Summary form only given. The LIOV (lightning-induced overvoltage) code, a computer program developed in the framework of an international collaboration involving the Universities of Bologna (Department of Electrical Engineering), the Swiss Federal Institute of Technology (Power Systems Laboratory), and the University of Rome “LA Sapienza” (Department of Electrical Engineering), is a numerical formulation of Maxwell´s equations, using the formulation of Agrawal et al. (1980) suitably adapted for the calculation of induced overvoltages when lightning strikes near a horizontal overhead transmission line. In the LIOV code, the electromagnetic field radiated by the lightning channel is calculated using the field equations in the form given by Uman et al. (1975) with the extension to the case of lossy ground introduced by Cooray and Rubinstein (1994) and assuming the modified transmission line (MTL) return-stroke current model (1988) for the description of the spatial-temporal distribution of the lightning current along the return-stroke channel