Lightning electromagnetic effects: do we know everything?

In the last twenty years, the widespread use of sensitive electronic devices has increased the interest in transients, in particular those caused by lightning (direct and/or indirect). This paper presents the latest developments in modeling the electromagnetic (indirect) effects of lightning. The progress in field-to-transmission-line coupling calculations for networks permits the analysis of more complicated structures subject to a lightning electromagnetic field. In parallel, it has been observed that the lightning current parameters obtained from measurements of real lightning strikes are polluted by the measurement arrangement, and that data decontamination is needed. Approximations using low-frequency coupling expressions that neglect the propagation in the case of complicated circuits with small dimensions are also discussed. Such approaches can give approximate solutions and orders of magnitude, helpful for correct EMC design for very complex configurations such as control and protection circuits in power-network substations, for instance