Zero-Vector-Placement-Based Power Ripple Suppression for Single-Stage Multi-Port Rectifier Under Unbalanced Grid Voltages

Active power ripple suppression serves as a promising solution to limit power ripples induced by three-phase gird voltage imbalances. These schemes, nonetheless, typically need to add supplementary power switches, resulting in increased costs. To alleviate the dilemma, a single-stage multi-port rectifier, which provides extra power control freedom for buffering power ripples with no extra power switches, is proposed in this article. Following that, an equivalent two-level model with a simple structure is employed to simplify the controller design for the rectifier. With the constructed two-level model, a zero-vector-placement-based power ripple suppression strategy is developed, which allows active power ripples induced by the unbalanced AC grid to be transferred into the ripple port of the rectifier. Finally, the experimental results based on a three-phase three-level multi-port rectifier system confirm the effectiveness of the proposed scheme.