Abstract :
Hitherto only two complete proofs of the circle diagram allowing for stator impedance and core loss have been published, viz. (1) Ossana´s method of repeated inversion, ¿and (2) Lamme´s algebraic proof. ¿ Both of these methods have disadvantages. The first is, to the best of the author´s knowledge, not accessible in English, while the second is long and involved and often difficult to follow. Further, neither of these methods gives any construction for the determination or graphic representation of the secondary equivalent current. A new proof is here published, which has the following features:- (1) It is a graphic proof throughout. (2) It gives an easy construction for the secondary equivalent current and, where the secondary winding is not short-circuited, for the secondary equivalent terminal e.m.f. (3) Its correspondence with the symbolic method is exact, so that at any stage in a problem symbolic methods may be substituted for graphical methods, or vice versa, with full confidence that the values obtained by the two methods are in exact agreement. Finally, the application of the diagram to the synchronous machine is developed.
