A Comparative Analysis of the Efficiency of Three- and Five-Phase Self-Controlled Synchronous Motors

It is found that, at equal values of the phase currents in three- and five-phase ac machines, the number of turns in a five-phase machine phase should be less than 3.5 times. Under these conditions, threeand five-phase windings create equal-magnetizing force with the same amount of copper. The inductance of the switched phases in the five-phase machine is reduced, which simplifies the switching of keys. The decrease in the number of turns in the five-phase winding also leads to armature-reaction weakening. The control range of the five-phase machine is expanded in comparison with that of the three-phase machine. The results of experimental research confirming the theoretical studies are given.