DSP based field-oriented control of induction motor with a nonlinear state observer

The paper deals with the implementation of a standard field-oriented induction motor control with a rotor flux nonlinear state observer, similar in structure to the well-known Luenberger observer for linear system. The real time control hardware used to implement the field oriented control and the nonlinear observer consists of a Data Translation single board DSP data acquisition system based on a TMS 320C40. After a brief description of the observer features and the proposed system, the experimental set-up is presented and discussed in detail. Experimental results demonstrate its excellent low sensitivity to rotor resistance variation in comparison to a field-oriented control system based on conventional current model flux estimation.