Analysis of harmonic current propagation generated by power electronic motor controls under nonideal conditions

Harmonic problem can be a serious problem in power systems. Typical case st udy is helpful for understanding the harmonic effects. This paper provides a novel method to establish some PSPICE macro models and apply these models to analyze the harmonics on the supply side and load side through a typica l structure, which include the thyristor rectifier controlled DC motor and the induction motor fed by the PWM rectifier-inverter. Through this method, balanced and unbalanced conditions are studied. Little unbalanced degree m ay cause large harmonic distortion at the converter input side. Experimenta l results are presented to validate the simulation results.