System for Monitoring Asynchronous Motors Powered at Variable Voltage

Abstract

This paper presents some experimental aspects related to the operation of asynchronous motors powered at variable voltage. A modern system for actuation of low-power asynchronous motors is presented, equipped with a voltage and frequency converter. Also, a data acquisition system is presented, with a sampling frequency of up to 100 kHz, supervised by an acquisition program that allows the visualization of the variations of the main characteristic sizes of the motor. The program contains both graphic interfaces developed by the manufacturer and by the authors of the paper. This program solves, among other things, an electromagnetic compatibility problem. The experimental tests carried out with the help of this system (in permanent non-sinusoidal regime at various power supply frequencies) are detailed. Technical details of the main system components are provided. The tests are accompanied by photos taken during the experiments and many original explanatory graphics. The authors' contributions are mainly in the software area. Thus, in the original program, a series of windows for harmonic analysis and visualization of the characteristic phasors of the analyzed electrical quantities were implemented. The paper ends with the main conclusions resulting from the completion of the study and with a representative bibliography.