Sustained Oscillation of an Inverter-Fed Induction Motor Drive System and its Stabilization

Abstract

Sustained oscillation of rotor speed is often experienced in PWM inverter induction motor (IM) drive systems. In this paper the sustained oscillation phenomena is investigated from the point of view of Hopf bifurcation theory. The sufficient and necessary conditions for existence of limit cycle are presented to determine bifurcation set in plane of stator voltage versus stator frequency. This research indicates that bifurcation set exists in the condition of IM inherent instability. At last, it is shown that V/f curve can be set to stabilize the sustained oscillation of rotor speed and results are numerically verified