On the Relation between Transient Reactance and Negative Phase Sequence Reactance of an Alternator

Abstract

In the previous paper, one of the present authors showed that the transient impedanco of an alternator just after the occurrence of short-circuit is equal to the negative phase sequence impedance in the sustained state. In the present paper this proposition is verified theoretically for an ideal alternator of zero resistance. The neglection of resistance is equivalent to admit the constant linkage theorem. Therefore the constant linkage theorem must infer the equality of the negative phase sequence impedance and the transient impedance just after the occurrence of short-circuit.
Further the transient reactance is showed to be approximately equal to the sum of armature leakage reactance and the field leakage reactance reduced to the armature winding, which fact has been generally appreciated by designers.