Optymalna praca silników indukcyjnych przy zmianach napiecia źródła zasilania

Most of induction motors operate at a load that is considerably lower than the rated load. It brings about a change in such energy indicators as power factor and efficiency that decide over electrical energy consumption. Economic efficiency of a drive system operation depends on those indicators and therefore optimum conditions for the motor operation should be created. If the motor load is lower than the rated load, voltage should be reduced or frequency should be changed to such a value that can ensure maximum values of the energy indicators. Possibilities of energy-saving operation of an induction motor with the regulation of voltage and feeding voltage frequency have been considered. Rules for the enhancement of such energy indicators as current input to the motor, power factor, and efficiency have been given. It is advantageous to feed a motor with voltage and feeding-voltage frequency that vary depending on the load degree as then energy consumption gets reduced. At the rated load a motor has to be fed with rated voltage and rated frequency but with decreasing load the voltage should be adequately reduced and the frequency adequately adjusted. Minimal feeding-voltage values are required at the open-circuit operation. Additionally, algorithms of voltage regulation that can ensure maintaining energy indicators at an adequate preset level have been presented. The indicators have been enhanced and electrical energy savings for various algorithms of voltage and frequency adjustment have been calculated.