Off-line co-simulation of multiphase PM motor-drives

This paper refers to the dynamic simulation of multiphase permanent-magnet motor drives featuring independent-phases structure. Based on the co-simulation approach with a finite element analysis, a circuital model is developed in which the usual inductive parameters and back-EMF coefficient are replaced by current and rotor position dependent functions, so that the exact electromagnetic nature and geometry of the machine is accounted. The model functions are pre-computed by a finite element analysis of a single phase of the machine. Then, the circuital model is solved by a dynamical simulator which implements also the drive system, converter and control. The proposed method is used to analyze the operation of a fault-tolerant five-phase permanent-magnet motor-drive for aeronautical application, controlled by BLDC technique. A comparison between the performance predicted by magneto-static analyses and dynamic co-simulation is presented, which clearly quantify the effect of the control detuning at increasing speed both in healthy and faulty-mode operations.