Patent ID: 8676524

Claim:
A system for computing machine parameters of an induction machine, comprising: a relation providing module operable to provide a relationship between slip rates and primary side resistances of the induction machine and a relationship between the slip rates and primary side reactances of the induction machine wherein each of the slip rates is a ratio of a difference between a synchronous speed of the induction machine and a rotor speed of the induction machine at a corresponding point of time to the synchronous speed; and a circuit parameter computing module coupled to said relation providing module and operable to perform a parameter computing process that includes the steps of a) generating a set of initial values of equivalent circuit parameters of the induction machine according to the primary side resistances and the primary side reactances corresponding to a set of predetermined slip rate values based on the relationship between the slip rates and the primary side resistances and the relationship between the slip rates and the primary side reactances obtained from said relation providing module, b) updating the set of initial values of the equivalent circuit parameters using correcting parameters that are obtained based upon a resistance error and a reactance error of the set of initial values of the equivalent circuit parameters with respect to the primary side resistance and the primary side reactance corresponding to each of the slip rates as obtained from said relation providing module, c) calculating a cumulative resistance error and a cumulative reactance error of the set of initial values of the equivalent circuit parameters updated in step b) with respect to the primary side resistance and the primary side reactance corresponding to each of the slip rates as obtained from said relation providing module, and d) repeating steps b) and c) until the cumulative resistance error and the cumulative reactance error are smaller than first and second error thresholds, respectively; wherein said circuit parameter computing module outputs the set of initial values of the equivalent circuit parameters as estimated circuit parameters of the induction machine when the cumulative resistance error and the cumulative reactance error are smaller than the first and second error thresholds, respectively.