The method to generalize engineering return stroke models

A method to generalize most engineering models is proposed. With the proposed method, the current discontinuity in the BG (Bruce-Golde) and TCS (traveling current source) models vanishes, and the generalized engineering models exhibit a good agreement with the measured optical characteristic features of the lightning return stroke, while the waveforms predicted by the generalized models still exhibit the same characteristic features as the original models. The influence of realistic features, such as a decrease in the return stroke speed and an increase in the current risetime with height, on associated electromagnetic field waveforms is investigated, and the results show that these two features tend to weaken the magnetic hump, but have no significant influence on the zero-crossing time.