Estimação dos parâmetros elétricos de um motor de indução trifásico utilizando suas curvas de desempenho

Abstract

Induction motors are present in a wide range of industrial sectors, being responsible for almost 30% of Brazil's electricity consumption. For the correct motor's drive and control it is required know its parameters values, however, the manufacturers usually do not present directly these parameters. The most usual method to obtaining these values is through tests, no-load test and locked rotor test. These tests are standardized but there may be unconformity between the standards. In order to simplify and automate the parameters estimation, this work proposes the use of a diferential evolution algorithm to estimate the electrical parameters of a three-phase induction motor, using data provided by the manufacturer's datasheet. For the validation of the method, the estimation was made using four models, combining two mathematical models and two circuit con gurations, but the control parameters of the algorithms were the same for the four scenarios. The simplest circuit and modeling model, excluding core loss resistance and supplemental losses was the one that presented the best result, in this case, the smallest tness of the four models, presenting errors less than 3% in relation to the known electrical magnitude, obtained through the motor performance curves. In none of the cases, the error for some magnitude was greater than 5%. Through the analysis of the parameters, it was possible to verify the behavior of the parameters and the power distribution through the equivalent circuit. This work also presented how these parameters behave when a non-sinusoidal voltage is driving it, also, working outside the nominal conditions, with reduced voltage and frequency, and then comparing what was obtained computationally with what was measured in laboratory.