Microprocessor implementation of an adaptive estimator for induction motors

The authors discuss the practical implementation of an adaptive estimator of electromechanical variables of induction motors, without a speed sensor. They present the implementation of the estimator in a 2-hp prototype. The estimator is based on two voltage integrators, implemented by hardware, and fully digitized as a consequence of the discrete nature of the pulse-width-modulation voltages. The choice of a stator fixed reference significantly simplifies the algorithm and, in addition, it presents little dependence on parameter variations. Adaptation of the DC components of the integration guarantees the stability, the convergence, and the robustness of the estimator. Experimental results confirm simulation results and suggest further improvement