Resumen
Procedure to estimate the rotation speed of the rotor of a three-phase induction machine starting from the current and voltage measurements of two of the power phases and the parameters of the machine (resistances, inductances, etc.). With this information, the x, y components of the spatial phasors of the stator voltage and the magnetization current of the stator are calculated; referred to the fixed reference system. With these components, two similar equations are obtained for the calculation of the rotor speed (velocity a and velocity b). To solve the problem derived from calculating the velocity equation when the denominator becomes zero; advantage is taken of the property that the denominators of the expressions velocity a and velocity b cancel each other with a phase difference of 90º. The calculation of the speed is done with that equation whose denominator is farthest from zero at each instant. (Machine-translation by Google Translate, not legally binding)