# Time Evolution of a Short Circuit Current

Time Evolution of a Short Circuit Current

When a short circuit occurs in a power system, the time evolution of the fault current depends mainly on the system's - (reactance to resistance) ratio and on the fault occurrence angle (measured relative to the system's voltage) [1].

X

R

This Demonstration shows a typical short circuit current (plotted in red) for a single phase, assuming no load current before time for simplicity. The fault current's DC exponentially decaying component is also plotted, as well as the positive and negative envelopes; these three components are plotted in dashed lines. The sinusoidal voltage is plotted in black.

t=0