KostenKo - State Technical university of St.-Petersburg, RUSSIA

Nonlinear electrodynamic characteristics of the return stroKe wave of cloud-to-ground lightning (equivalent Z(eq) impedance and phase V(ph) velocity) are estimated on the basis of the approximate description of the return stroKe using quasi-linear Partial differential equations. These equations contain nonlinear Parameters which depend on instantaneous values of the current in the front of the wave. Besides, a method for calculation of overvoltages on the High Voltage line of worked out for the case of direct lightning stroke, taxing into account nonlinear impedance of lightning and wave Processes in the line.

Waves, Lightning, Impedance, Phase velocity.