Assessment of short-circuit conditions in the interconnected local distribution system

This paper analyzes how to calculate the symmetrical and unsymmetrical short-circuit currents. The main reason of this thesis is to give, step by step, a complete method for the calculating of short-circuit currents and his mechanical or thermal stresses in local distribution network. The calculation is applying on medium-voltage AC power networks and takes into account the recommendations of the IEC 60909-0 standard. Thesis also deals with limiting of short-circuit current when the short-circuit withstand capability of equipment within power network is exceeded and evaluation of individual variants of this limitation.