ABSTRACT
If an unsymmetrical fault occurs, the current in the three lines become unequal and so is the phase displacement among them. It may be noted that the term “unsymmetry” applies only to the fault itself and the resulting line current. However, the system impedances and the source voltage are always symmetrical through its main elements, namely generators, transmission lines, synchronous reactors, etc. ere are three ways in which unsymmetrical faults may occur in a power system.
