A Procedure for Determining Variable Parameters of Induction Motor Models

摘要

The model of an idle-bar induction motor is proposed, and an off-line identification procedure concerning this model is presented in the paper. The motor is portrayed by an equivalent circuit with variable parameters. The structure of functions describing the parameters arise from design calculation procedure. Solving the equivalent circuit requires an iterative multi-loop approach. The coefficients of functions describing the model parameters are determined through an identification process and the nonlinear regression method is applied to reach the goal. Related optimisation problems are defined and solved. The proposed model is compared with a model obtained on the assumption that the motor is portrayed by a double-cage representation of the equivalent circuit. Three versions of this model are considered and submitted to the same identification process. In all cases the reference quantities are measurement data relevant to the type test of the motor. Such data as stator currents, input powers, supplying voltages, and angular velocity concerning rated condition as well as no-load and starting characteristics, are employed. The results of identification for all cases in the form of corresponding figures and tables are presented and discussed. Most important conclusions arising from the comparison and concerning the choice of the model are drawn.