Investigation of different types of winding in counter-rotating double-rotor axial flux permanent magnet machines

ABSTRACT The choice of the winding type has a significant effect on the performance characteristics of the machine, efficiency, weight of the required wire, ease of winding, etc. The purpose of this paper is to investigate the effect of winding type as well as the polarity of magnets on both sides of the stator core on the back electromotive force (Back-EMF) of the counter-rotating double-rotor axial flux permanent magnet generator (CRDR-AFPMG). The winding type influences the produced voltages of the generator. Hence, in this paper, several types of windings, such as the first type of shifted winding, the second type of shifted winding, and the independent winding are investigated to produce three voltages with the same amplitudes and 120 degrees of phase differences. However, it has been found that, among the studied windings, only the second type of shifted winding and independent winding produces three voltages with similar amplitudes and 120 degrees of phase difference. Finally, the suitable type of winding for the proposed machine will be determined, and the performance of the case study machine will be evaluated by finite element (FE) simulation. JMAG designer software is used for this purpose.