A Novel Voltage Judgment Component Injection Scheme for Balanced and Unbalanced DC-link Voltages in Three-Phase Vienna Rectifiers

In three-phase ac/dc power applications, the dc-link voltage of the Vienna rectifier can function as a dual-output independent voltage source. This enables it to fulfill various output voltage requirements for dual-loaded dc-link buses. These requirements may arise owing to different charging rates applied to the dual loads or other factors that cause unbalanced voltage at the output capacitor terminals. To address these scenarios, this article introduces a novel voltage judgment component injection scheme (VJCIS) for Vienna rectifiers. The VJCIS considers the effective reduction of input current distortion and neutral point voltage oscillation in both balanced and unbalanced capacitor voltages. These improvements enhance the dc output performance, allowing the simultaneous control of balanced and unbalanced output voltages to satisfy the requirements of dual-port and parallel charging applications. The proposed VJCIS method only requires the identification of specific continuous intervals and clamping intervals using the input voltage signal and reference voltage to enhance the dc output voltage performance and eliminate zero crossing distortion in the input current. Experimental results in the practical implementation of a 2.4-kW Vienna rectifier confirm the effectiveness and correctness of the proposed method.