Bursting oscillations and bifurcation mechanism in a permanent magnet synchronous motor system with external load perturbation

Abstract

Abstract This research aims to study the bursting oscillations and bifurcation mechanism in a permanent magnet synchronous motor (PMSM) system with external load perturbation. When an order gap exists between the external load perturbation frequency and the natural frequency of the PMSM system, the PMSM system exhibits bursting oscillation behaviors. First, the mathematical model of a PMSM with external load perturbation is established by considering the external load perturbation as a slow-varying parameter. The PMSM system is transformed into a generalized autonomous PMSM system. Second, the Fold and Hopf bifurcation conditions of the PMSM system are obtained through bifurcation analysis. Third, the bursting oscillations and bifurcation mechanism of the PMSM system are analyzed in detail by using equilibrium point distribution and bifurcation diagrams, transformed phase portraits, and time series diagrams. The PMSM system exhibits periodic symmetric Fold/Fold bursting oscillations and periodic delayed subHopf/subHopf bursting oscillations, as the parameters change. When the amplitude of the external load perturbation changes and the PMSM system parameters are fixed, the bursting oscillation processes in different ranges of amplitude are revealed.