抄録
The two-axis theory is now recognized as the most important theory of analysis of synchronous machines. However, some problematic points have been left in its basic theory.
The first point of them is that the physical meaning of dq-transformation is not clarified sufficiently.
The second point is that the transformation of rotor windings caused by dq-transformation of armature winding is not discussed at all.
The third point is the problem of base values of rotor quantities in per-unit system. A. W. Rankin recommended the use of the armature-reaction-based base values of rotor quantities as an improvement of Park's base values. However, the derivation of the formulae of them is not so simple, and besides, his theory is not completely obvious.
The first point has already been resolved by the author's previous paper. The second and the third points are resolved in this paper using the results of the previous paper.
The resolution of the second point can be obtained by the application of the ratio of change of air-gap magnetomotive force and that of air-gap flux which are caused by dq-transformation of the armature winding to the rotor windings.
The resolution of the third point can easily be obtained by the use of the results of the resolution of the second point. From the point of view of theoretical transformation, the correction factor for field magnetomotive force is separated into winding-factor component and non-uniform air-gap component.
From the results of comparison of existing formulae of base values with those obtained in this paper, it is proved that all the existing formulae for the base value of field current are correct, but the existing formulae for the base values of field voltage and field winding resistance are not reasonable in the case of salient-pole machine.
