Comparative Study of Methods to Evaluate Three Phase Induction Motors Loading

There are several methods for evaluating the loading condition of three phase induction motors (TPIMs). This evaluation allows inferring about the technical feasibility of replacing the motor in use by another one of less power, contributing to the efficient use of electric energy. The work presented in this document consisted of a comparative evaluation of the Linearization (LM) and Characteristic Curves (CCM) methods; as well as those used by the software BD Motor and MarkIV Plus. The results obtained with the application of the methods were compared with reference values, which were acquired through laboratory tests of the TPIM. In the laboratory tests, a computerized bench consisting of a TPIM and a dynamometer was used. Finally, the methods were compared to each other, leading to the conclusion that the method with the best precision is the CCM, followed by the current method used in MarkIV Plus software. However, the latter uses more accessible information than the required by the CCM.