Research On Stator Core Loss For Induction Motor Fed By SPWM Inverter

With the continuous development of power electronic technology,the induction motor fed by inverter power supply is widely applied in the drive system,due to their brilliant speed control performance and control characteristics.However,the inverte r output voltage contains a lot of harmonic components,it might cause the increase o f motor core loss and the motor temperature,acceleration of the motor insulation agi ng and other issues.With the development of variable frequency motor control techn ology,in the actual application process,filters are added to the control circuit of the v ariable frequency motor to improve the quality of the power supply.The stator core l oss accounts for a large proportion of the total core loss.Therefore,it is necessary to study the stator core loss of the motor under the inverter.This provides a reference for guiding the operation and design of the motor under the inverter.This dissertation takes a 37 k W variable frequency induction motor as the research object,combines with some actual circuit parameters of the components used,set up the two-dimensional transient electromagnetic field-joint frequency conversion circuit calculation model,based on the electromagnetic field theory,use the time-step finite element to calculation and analysis the stator core loss fed by inverter power.Under the situation with and without the filter,the SPWM output waveform has been analyzed,with the variation of modulation ratio and harmonic distortion rate of load side regular pattern variation,based on SPWM inverter control circuit model.Contrast research to the voltage frequency 50 Hz,rated load conditions,and join the filter before and after the inverter power supply of power supply mode of stator tooth tangential magnetic density and yoke of radial magnetic density waveform,the stator core loss distribution,contrast study modulation parameters,voltage frequency changes and load condition changes,join before and after the filter,the stator core loss,finally through the prototype experiment,the measured values in the experiment and calculated values were comparative analyzed to verify the accuracy of the model.