Problematika zkratových proudů v trojfázových střídavých soustavách.

Abstract

This thesis deals with short-circuit currents in three phase AC systems. In the first theoretical part I describe types, the most common causes of short circuits, the effects of short-circuit currents and possibilities how to limit short-circuit currents and their consequences. The second part describes the definition according to standard EN 60909-0, describes the process of short-circuit current and methodology for calculating short-circuit currents according to the above standards. Next section contains equations to calculate the impedance of the circuit elements of the short circuit. The following are equations for calculating short-circuit currents in three-phase, biphasic, biphasic earth and single-phase short circuit. In the final section I present the example of calculating short-circuit currents in power system according to the methodology according to standard EN 60909-0, which I described in previous chapters.