Short-circuit analysis

CYPELEC analyses short-circuit currents using the symmetrical components method in accordance with the IEC 60909 standard. This method, based on Thevenin's theorem and applicable to all types of networks up to 230 kV, consists of the induction of an equivalent voltage source at the short-circuit point and the replacement of each element of the fault loop by its corresponding direct, inverse and zero sequence impedances. Once this system has been established, the short-circuit current is obtained at the same point where the "virtual" voltage source was placed.

Thanks to its remarkable analytical aspect and higher accuracy compared to other procedures, it is the best tool for analysing system defects.

Scenarios for the analysis of short-circuit currents

The maximum and minimum short-circuit currents are checked for each of the established supply scenarios, if there is more than one, so that the protective devices ensure short-circuit protection for all power supply sources.