Stabilizing the sustained oscillation in an induction motor system with indirect field-oriented control by time-delayed state feedback

The sustained oscillation often appears in the induction motor (IM) systems with indirect field-oriented control (IFOC) and essentially caused by the unstable equilibrium points undergoing Hopf bifurcation. In order to stabilize these undesirable oscillations, a convenient time-delayed state feedback method is presented and its accomplishing process is indicated for a tested IM system in detail. It is clarified how to stabilize the unstable equilibrium points by selecting suitable feedback gain and time delay of the time-delayed feedback controller, and the analytical results are validated using time-domain system simulation.