Abstract :
The analysis of unbalanced power systems depends usually on transformation methods by which the phase quantities are substituted by, for example, symmetrical component quantities. These transformations had the computational advantages in the past, but with the use of digital computer, they no longer appear to be necessary. In this paper the analysis of power system faults including the simultaneous ones has been undertaken with the help of phase coordinates, i. e., the actual system phase voltages, currents and impedances. This approach is found to be simple and readily adaptable to digital computer techniques. Symmetrical components are, however, used as a measure of the system unbalance.
