Influence of transient conditions
Protection of transportation and distribution networks against short-circuits and insulation defects

Due to the nature of network elements (capacitors, inductances, resistors), the transition from one operating state to another, particularly when a short-circuit occurs, cannot take place instantaneously and gives rise to transient current and voltage regimes.

The performance of modern high-speed protection systems depends not only on their intrinsic qualities but also, to a large extent, on the response of the measuring gearboxes to these transient conditions.

The choice of protection is in fact consistent with that of the instrument transformers and vice versa; the analysis of the performance of protection systems must take into account the behavior of the whole.