Microcontroller-Based On-Line Self-Tuning of the Rotor Time Constant for Field-Oriented Induction Motor Drives

A microcontroller-based on line self-tuning of the rotor time constant for a field oriented control of induction motor is presented, based on a power transfer method. The binary search approach to adaptation is considered, a method particularly suited for digital implementation with low-cost, fixed point devices. The robustness to discretization and quantization errors, the easiness of the set-up, and the inherent stability are the main characteristics of binary search. Simulation and experimental results confirm such a method as an interesting alternative to the standard integrator solution.