Robustness of passivity-based controller (PBC) for current-fed induction motors

The robustness of a newly developed passivity-based controller (PBC) with respect to variations of the rotor resistance when tracking the desired rotor speed and flux magnitude for a current fed induction motor has been investigated. Although stability is maintained for large variations, the flux tracking error converges to zero only if the motor is unloaded. Otherwise a large steady state error occurs. This lack of robustness limits the practical applications of the PBC