Abstract
The effect of the various winding connections of three phase two windings transformer on the fault current at the line to ground (SLG-fault) and the double line to ground (DLG-fault) is studied. The ground faults are unbalanced ; so, the analysis of these types of short circuit faults is divided into three balanced circuits which are known as symmetrical networks. The zero sequence impedance appears in some types of transformer connections and its effect is reflected in the fault current value. This paper examines with help of MATLAB software by simulating a generating station and different transformer connections, the impact of three-phase two windings transformer connections which occurs on a transformer secondary side to determine which the connections type of the transformer gives the maximum and minimum zero sequence component of ground fault current.
