Energy Conversion in DC Excited Flux-Switching Machines

This paper initiates a study on energy conversion in dc excited flux-switching machines (DCEFSMs) to reveal the torque production mechanism of this type of machines. The flux linkage components and self- and mutual inductances of a single-phase two-rotor-tooth DCEFSM are investigated. Based on the understanding of the relation between these variables and the rotor position, two different switching strategies are implemented to the armature current of this machine. Current-flux linkage loops are sketched for each switching strategy, resulting in different torque expressions. These torque expressions, validated using finite element analysis, show that the DCEFSM is a reluctance machine in which torque is generated due to variation of self- and mutual inductances. In addition, the torque component related to the mutual inductance can be dominant with certain current commutation in the armature winding.