Analysis of low power asynchronous motors operation at variable voltages and frequencies

The electromechanical conversion is a very important aspect in the conversion process of the energy; it is carried out by means of the electrical machines used in all areas of the human activity. By using the electronic computer in the electrical machines design, there can be obtained some better operation characteristics, there can be decreased the losses of electrical energy and increased the power factor. The computer-aided conception becomes a numerical laboratory, where the prototypes are built and tested. Improving the design quality cannot neglect the saturation in case of machines strictly dimensioned from electrical and magnetic point of view. Developing some performant electrical drives with high response speed and exploring closer and closer by the stability limit of the asynchronous motors have led to intense preoccupations, both in our country and abroad, for determining the parameters precisely. The research carried out proves that the low speed operation means an increase of the machine losses, by 18.2% and a low decrease of the reactive power consumption, by 5.1%.