Analysis Of Iron Loss For Induction Motor Fed By Pulse Width Modulated Inverter

Cage induction motor because of its simple structure, reliable operation, lowprice, it is widely used in the drive system. In today’s energy problems becomemore serious, reducing the loss generated by the motor, the motor efficiency is ofgreat significance to improve, so the accurate calculation of loss becomes critical.In the motors, iron losses accounted for a large proportion of the total losses.Now more and more motors are supplied by power inverter, to effect directly thedistribution of electromagnetic fields in the motor so that the internal core has alot of harmonic components, thereby increasing iron loss. Also, because themotor drive different loads in real time requires intermittent starting, frequentload changes. Therefore, analysis of the iron loss of different load inductionmotors under inverter power is essential.In this paper, a Y2-250M-4,55kW cage induction motor as research subjects,on the basis of the electromagnetic theory, given the basic assumptions, thecalculation model of a two-dimensional field-circuit coupled time-stepping finiteelement was established with the55kW three-phase asynchronous motors. Thestator and rotor iron losses under sinusoidal power asynchronous motor loadchanges were analyzed calculations to determine the size and distribution ofmotor stator and rotor iron loss. Electromagnetic characteristics of inductionmotor load changes were analyzed. And then design an asynchronous motorinverter control circuit, to build the field-circuit coupling time stepping finiteelement model with inverter control circuit. The stator and rotor iron losses underinverter power asynchronous motor load changes were analyzed calculations Thecalculated value of iron loss induction motor load changes of two power supplycomparative analysis to study the effects of inverter power on asynchronous motor iron loss. After studying the effects of modulation ratio and switchingfrequency of the inverter parameters on iron loss under inverter power supply.Finally, the calculated values of the motor parameters and laboratory testswere comparative analyzed to verify the accuracy of the calculation. The usefulconclusions were obtained by calculating to guide the optimization of the motor,and lay the foundation for the subsequent calculation of the temperature field.