Increasing of thermal reliability of a regulated induction motor in non-standard cycle time conditions

Currently there is no information about the level of cycle time and the duty rating effects on a thermal state and insulation live of induction motor drive, which essentially influences on service reliability. The electrothermal model, which allows considering peculiarities of electromagnetic energy transformation in thermal energy, heat transfer and heat exchange processes, was used for calculation and analysis of the thermal state of induction motor drive. The research has approved that the magnification of cycle time and high value of working slips of the induction motor drive leads to essential growth of its temperature. The estimation of the insulation live which has displayed lowering of the insulation live indexes to 12 times - for the rated induction motor slip s=0.1 and to 50 times - for working induction motor slip s=0.9. Correction current coefficients of the induction motor are defined, supporting its rated thermal conditions.