Experimental Investigation of Brushless Single-Unit Frequency Convertors with Distributed Permeance Rotors

To avoid instability of single-unit frequency convertors with distributed copper rotors described by the author [1], a variation of the machine is described here. The basic principle of power exchange between two windings of different pole numbers has been retained. In this machine the rotor iron is shaped to produce the necessary dissymmetry. This eliminates the discontinuity in the generated voltage near the synchronous speed of the primary field. Results from various experimental machines are discussed. Other interesting characteristics of the apparatus are presented.