Modular Dynamic Model for Multi-Three-Phase Electrically Excited Synchronous Machines

Multi-three-phase electrically excited synchronous machines can enable the electrification of applications featuring stringent requirements in terms of fault tolerance and reliability, as in the aerospace industry and in sustainable energy generation. Indeed, the presence of multiple stator three-phase winding sets improves both redundancy and operational safety. Moreover, the regulation of the excitation achieved by means of the rotor winding enables the possibility of completely de-energizing the machine in case of faults. Furthermore, the rotor current regulation allows achieving high efficiency and power factor in a wide speed range. However, multiple stator three-phase sets and the presence of a variable rotor current result in nontrivial dynamic modeling, particularly when considering the iron saturation nonlinearities. In this framework, a multi-stator formulation for the nonlinear dynamic modeling of the multi-three-phase electrically excited synchronous machine is developed. The multi-stator approach interacts with a separate rotor model for the computation of the excitation flux linkage dynamics. The accuracy and capabilities of the proposed model in representing fault conditions are evaluated in simulation using the data of a quadruple-three-phase motor.