ADAPTIVE TORQUE CONTROL OF INDUCTION MOTORS WITH UNCERTAIN STATOR AND ROTOR RESISTANCES: RESULTS OF EXPERIMENTAL RESEARCH

Experimental research results of novel adaptive to stator and rotor resistances variations torque-flux vector control system of induction motor are presented. System is designed on the base of local separation principle for nonlinear sys-tems. Adaptive system is composed from globally exponentially stable torque-flux indirect field oriented subsystem and locally exponentially stable adaptive to stator and rotor resistances subsystem. The study was performed for autonomous operation of control and parameter identification subsystems and for adaptive controller with replacement of actual rotor and stator resistances by estimated ones, obtained in real time by identification subsystem. Robustness study shows that adaptive with respect to rotor resistance variation controller is sensitive to stator resistance uncertainties, while adaptation for both resistances allows to achieve local asymptotic torque-flux tracking, field orientation and asymptotic resistances estimation. Experiments show that adaptive controller (19-th order dynamic system) is implementable using available DSP-technology, achieved performances are suitable for commercial implementation.