Parameter extraction of lightning impulse with overshoot or oscillation

For the controversy on the measurement of lightning impulse with superposed overshoot or oscillation in IEC 60060-1Ed.2.0 (1989), this paper introduces test voltage factor method, residual filtering method, and curve fitting method based on double exponential model, and indicates their superiority to other methods. The procedure for calculating digital waveforms with overshoot or oscillation in IEC 60060-1Ed.3.0 (2008) is analyzed, and the incoherence of waves and the ambiguity of definition in practice are presented. The procedure is accomplished with the analytical data of TDG1.12 to perform waveform process, parameter extraction, and result analysis. In addition, the references of wave parameters are suggested for dealing with lightning impulses and extracting the parameters.