Real-time estimation of the electric parameters of an induction machine using sinusoidal PWM voltage waveforms

This paper studies the parameter estimation of induction machines. The prob lems associated with the parameter estimation of induction machines are ana lyzed through sensitivity functions. Then, models and a procedure to estima te a set of four basic parameters (r(s), sigma l(s), l(s), and tau(r)) are proposed. The discrete-time parameter estimation models are written in the delta operator specifically because it provides good numerical properties a t high sampling rates, where the discrete-time model approaches its continu ous-time equivalent. This feature permits the direct estimation of the cont inuous-time parameters. The main feature of the proposed procedure is the p ossibility to estimate the parameters by using sinusoidal signals, and with out the measurement of the machine speed. The experimental results obtained with the proposed estimation procedure are presented and demonstrate that it is possible to map the parameters in terms of the operating conditions o f the induction machine.