Analysis of brush DC equivalent controlled multiphase cage rotor induction machines

In a brush dc equivalent (BDCE) controlled machine, quasi-square like constant air gap flux density and rotor induced voltage waveforms are utilized. Analytical expressions for calculating the developed power, flux density, stator and rotor copper losses for the BDCE controlled cage rotor multiphase induction machine are developed in this paper. From analysing these expressions, it is found that, for a BDCE controlled machine with a certain torque and a certain flux density, there is a best (optimal) combination ratio of field to torque phases. Also, in this paper, measurement results in a prototype cage rotor multiphase induction machine drive are presented.