Power quality degradation effects on PWM voltage source inverter with diode bridge rectifier

The paper describes the effects of power quality degradation on the AC input current response of three-phase PWM-VSI adjustable speed drive with diode bridge rectifier. The study accounts for different voltage nonideal conditions, showing the results obtained in presence of single and multiple disturbances, like harmonics, fluctuation and unbalance. The findings of the paper confirm that the main key factor in determining the severity of voltage harmonics relays in the peak value of voltage supply rather than only in its harmonic content. Further, the equivalent supply impedance parameters play a crucial role to assess the final input current distortion. Finally, fluctuation and imbalances in the power supply voltages generate not only unbalanced input current harmonics, but also additional interharmonic components that, in case of voltage fluctuations, are considerably increased