Single line to ground-fault (SLG) fault is the record frequent fault probable to occur
in an electric power system. The effect of ground-fault is determined by using grounding method
and transformer connections. In this study, the simulation showed the performance of a simple
power system within the SLG fault in the system at various transformer connection and generator
grounding method. New approach the application of ground fault current calculation using
symmetrical components method on unit generator transformers. A symmetrical components
method applied with simulation was conducted in Matlab software. The results were then
analyzed, presenting a comparison with the fault impact at various transformer connection and
generator grounding method. The models of transformer connection for each side (primary and secondary) used were wye (Y), wye-grounded (Yn) and delta (). It was clearly shown that the ground-fault currents at the generator bus had significantly an effect on the type of the
transformer connections used during the ground-fault at the secondary side of the transformer.
Keywords; symmetrical components method, ground-fault, transformer connection