Function representation of lightning impulses produced by a testing circuit with continuity of voltages and currents at a tested object

Mathematical formula describing full and chopped lightning impulses occurring when a tested device is represented by a complex impedance, and for nonzero initial conditions at a chopping moment, have been derived. The derived method of parameter calculation of the formula fitting chopping of the impulse is presented. Interpolation formulas for computation of the full impulse formula coefficients are proposed. An application example of the method is also given.