Methods to Evaluate the Quality of Stator and Rotor of Electric Motors

Sebastião Lauro Nau

WEG - Manager of Research and Technological Innovation

Short Biography:

Sebastião Lauro Nau received his Engineer, M. Sc. and Doctor degrees from the Universidade Federal de Santa Catarina, Florianópolis, Brazil, in 1985, 2000 and 2007, respectively. He is currently Manager of Research and Technological Innovation at WEG Equipamentos Elétricos S.A., Jaraguá do Sul, Brazil, and a Professor at the Department of Electrical Engineering, Centro Universitário - Católica de Santa Catarina, Jaraguá do Sul, Brazil. His work and research topics are induction machines, magnetic noise, synchronous motor with permanent magnets and application of motors with frequency inverters.


This paper describes some innovative methods for evaluating the design quality and the actual condition of an electric motor. Some techniques discussed below were developed inside the company with the aim of increasing the reliability in the assessment of the stator and/or the rotor of a squirrel cage motor. The methods discussed for stator evaluation involve the measurement of iron losses and the realization of accelerated ageing tests, concerning the quality in the design stage of an electric motor. The methods discussed for rotor evaluation involve procedures to check the continuity of the bars and short circuit rings, concerning the quality in the manufacturing stage and allowing assessments of the actual condition of the machine in the field.