Stability analysis of GTO-CSI induction machine drive using constant rotor frequency control

The instability phenomena associated with GTO-CSI induction machine drive systems using a constant rotor frequency control scheme are investigated in this paper. It is indicated that a high frequency instability is caused by an LC resonance between machine leakage inductance and output filter capacitor through current feedback schemes. A low frequency instability is associated with the variations in rotor (slip) frequency and the output capacitor. Physical interpretations for these instabilities are presented and strategies for eliminating them are proposed. Time-domain simulations and experiments were performed to verify the analysis results