On some parametric and phase space singularities in PMSM submitted to FOC drive

This paper describes the occurrence of certain dynamic responses of the permanent magnet synchronous motor submitted to a FOC control under a parameter variation. In addition to the transition between limit cycles and equilibrium points due to the Hopf bifurcation, the multistability property is put into evidence by the identification of several attractors for the same motor and control parameter sets and for different sets of initial conditions. An illustration of the domains or basins of attractions of different attractors is given in a three dimensional phase space. Analytical expressions of equilibrium point coordinates are determined from the differential system equations; their stability can be known from the characteristic polynomial solutions.