Adaptive fuzzy techniques for slip-recovery drive control

Speed adjustments can be achieved for wound-rotor induction motors by slip power control, but power factor problems limit the usefulness of the scheme. In the modified Scherbius system described, a generalized hybrid inverter is utilized to regulate the slip-energy recovery and the power factor of the system, for all regimes. The fuzzy adaptive control is based on a three-level control structure. Each level, described by a set of linguistic fuzzy rules, is responsible for a specific task. Together, the three levels constitute a flexible adaptive control structure that manipulates the system variables, improving the drive performance as the system evolves