An Improved Modulation Strategy Without Current Zero-Crossing Distortion and Control Method for Vienna Rectifier

Vienna rectifier with simple structure, which has gained popularity in recent years for ac to dc power conversion for many industrial applications such as electric vehicle charging systems and uninterrupted power system (UPS) systems, accomplishes the operation of unit power factor. However, the distortion of the input current near the zero-crossing point is a puzzle that will increase the current harmonic content. In this article, the cause of the zero-crossing distortion is analyzed, and an improved space vector pulsewidth modulation modulation strategy is proposed. Moreover, the sliding mode control for the outer voltage loop and the phase compensation multiresonance control for the inner current loop is proposed to improve the dynamic response performance of the dc side and achieve zero-error control of the ac side. Simulation and experimental results verify the effectiveness of the proposed modulation scheme and control strategy.