Effects of Current Time-Delayed Feedback on the Dynamics of a Permanent-Magnet Synchronous Motor

We investigate how the dynamics of a permanent-magnet synchronous motor (PMSM) depends on current time-delayed feedback, in which the delay time is both fixed and varying in time. We choose model parameters for which the PMSM displays, in the absence of feedback, chaotic oscillations. The stable operation islands of the PMSM are first investigated in the parameter space of feedback gain and delay time. Then, detailed regimes of motion can be explored by bifurcation diagrams. It is found that the dynamic delay time feedback can obtain stabilization of unstable steady states over a much larger domain of parameters in comparison with the static delay time feedback. The mechanism behind the action of current time-delayed feedback is also addressed. This brief may provide a useful tip for maintaining the security operation of electromechanical systems.