Theory of the Bridge-Rectified Synchronous Generator with a large Number of Stator Phases - Part I

In order to improve the characteristics of a bridge-rectified synchronous generator, the number of stator phases is increased. This paper discusses the basic theory of this machine, which turns out to be ati interesting cross link between the DC commutator and the AC synchronous machine. A mesh connected stator winding is found to be preferable to a star connection and the stator thus becomes the equivalent of a conventional DC armature with each previous commutator bar replaced by two diodes. Commutation is now initiated by the mainpole and the commutation zone changes in width and location as a function of load. Consequently, commutation has a major influence on the required excitation and the general characteristics of the machine. The theory presented is based on the general MMF distribution in the airgap and deals with actual non-sinusoidal quantities. The theory is also adaptable to brushless DC shunt and series motors with an optional compensating winding. Part II discusses a numerical example in detail.