A new control scheme of the three-phase four-wire PWM converter under unbalanced and distorted input conditions

This paper presents circuit model and mathematical model of power for three-phase four-wire PWM converter under unbalanced and distorted input voltages. Based on the system model, a new positive-negative-zero sequence current reference control method is proposed to eliminate of harmonics of DC link voltage to alleviate the stress of the DC-link capacitor and to reduce the harmonics of input AC currents. The results show that the proposed control method has better performances than the conventional single positive sequence control under unbalanced and distorted input voltages.