High Gain Proportional Resonant Voltage Ripple Suppression for PWM Rectifiers Under Unbalanced Grid

Pulsewidth modulation rectifiers ensure a sinusoidal waveform of the input current, achieve a unit power factor, and maintain a stable dc voltage. However, under unbalanced grid conditions, the grid current becomes distorted, and the dc voltage exhibits a secondary ripple. To solve these problems, this article proposes a high gain proportional resonant (HGPR) ripple suppression method, the ripple suppression speed of the HGPR is faster than that of proportional resonant controllers, compared to quasi proportional resonant controllers, the HGPR controller offers higher gain and reduced steady-state error while maintaining a similar bandwidth and thus not affecting the stability of the system while maintaining the same parameter configuration. Compared with the existing dc voltage ripple suppression methods, the method proposed in this article has stronger ripple suppression capability, lower computational complexity, and excellent dynamic performance. Finally, the experimental results demonstrate that the proposed HGPR method can achieve low ripple dc voltage and low total harmonic distortion of current under grid voltage unbalance.