A Hybrid Control Strategy Based on Lagging Reactive Power Compensation for Vienna-Type Rectifier

The Vienna-type rectifier is widely used in many applications due to the merits of controllable dc-link voltage, realizable three-level operation, and compact size. However, the input currents near the zero-crossing point are distorted inevitably due to its special topology. Based on the analysis of the causes of current distortion, a lagging reactive power compensation method is proposed. The d-q-axis current models are developed, and two finite-time current controllers are designed to enhance the interference suppression performance. The asymptotic convergence of the d-q-axis current systems is proved, respectively. In addition, neutral point potential balancing is achieved by employing a proportional controller without increasing the cost of the system. The validity of the proposed hybrid control strategy has been verified by simulation and experimental results. Compared with the conventional strategy, this new hybrid control strategy can help to achieve excellent performance and stronger disturbance rejection.