1. Technical and standards developments

1.1 Improved understanding of low-voltage phenomena

For a long time, studies of low-voltage transient phenomena were limited. In particular, the relatively good intrinsic strength of equipment meant that precise studies were not necessary. This is no longer the case, and in recent years a large number of studies have been published on the subject.

Simulations, on-site measurements and laboratory tests were carried out, providing invaluable information on surge statistics, amplitudes, the performance of different equipment, and the necessary locations and characteristics of surge arresters.

Thus, while often considered negligible, maneuvering overvoltages can, in certain configurations, be as severe, or even more so, than lightning overvoltages....