Synchronous machines I-an extension of blondel's two-reaction theory

Abstract

Blondel treated salient pole machines by resolving the fundamental space component of m. m. f. along the two axes of symmetry-the direct axis of the pole, and the quadrature axis between poles. Using this idea, and applying harmonic analysis, Blondel's theory has been extended in the present paper to a comprehensive system of treatment, in which the effect of harmonic m. m. fs., as well as the fundamental, and also of field m. m. f. in the quadrature axis, as well as in the direct, have been taken into account. It is shown that the "armature leakage flux" which causes reactance voltage drop in synchronous operation, comprises all fluxes, due to armature currents, which generate fundamental voltage, except the space fundamental component, the latter constituting the total flux of "armature reaction." Impressing upon the variable air-gap permeance those space harmonics of m. m. f. which are due to the fundamental time component of current and which therefore rotate at various fractional speeds, produces odd space harmonics of flux rotating at many different speeds and in opposite directions. Some of these, listed in Table I, produce fundamental voltage, but most of them generate time harmonics. The former, which are reactive voltages, are only those of the nth space order rotating at one nth speed-that is, those which correspond in space order and speed to the harmonic m. m. fs.