Optimal rotor flux shape for multi-phase permanent magnet synchronous motors

Abstract

In the paper the power-oriented graphs (POG) technique is used for modeling m-phase permanent magnet synchronous motors and a study on the optimal rotor flux is given. The POG model shows the ldquopowerrdquo internal structure of the considered electrical motor: the electric part interacts with the mechanical part by means of a ldquoconnectionrdquo block which neither stores nor dissipates energy. The dynamic model of the motor is as general as possible and it considers an arbitrary odd number of phases. The rotor flux is analyzed, in particular in order to minimize the currents needed for the torque generation, and its optimal shape is given. The model is finally implemented in Matlab/Simulink and the presented simulation results validate the machine model and the rotor flux choice.