Comparative study of three minimization methods applied to the induction machine parameters identification using transient stator current

To identify the parameters of asynchronous machines, many methods are used. Many of them need a derivative during the optimization process. Unfortunately, a derivative function amplifies any noise due to numerical calculation or to measurement. As a consequence the search of the vector of parameters becomes difficult. Three minimization methods without derivatives are presented and applied to the identification of the parameters of induction motors. They allow finding both electrical and mechanical parameters from the analysis of the starting stator current and the corresponding voltage. Firstly, each method is described. Secondly, for a given machine with known parameters, numerical simulations allow to test the methods in terms of computer consuming time, of convergence and uniqueness of solution. The last part is devoted to the applications of the methods in order to identify the parameters of two asynchronous machines.