An Integrated Control Method for Improving the Input Current of Paralleled Vienna Rectifiers

The circulating current (CC) occurs among the paralleled converters due to the inconsistency of impedance parameters, carrier phases, switching frequencies and so on, and for Vienna rectifier, which contains the current distortion problem, will bring worse input current. Therefore, in this paper, an integrated control method is proposed to suppress the CC and current distortion. Specifically, the modeling of CC in paralleled Vienna rectifiers is established, on the basis of normal zero-sequence circulating current (ZSCC) control, a feedforward control is added to eliminate the ZSCC spikes. For the current distortion, the corresponding analysis and solution in space vector modulation (SVM) is conducted, to facilitate the implementation, the zero-sequence component injected by the equivalent carrier-based PWM method is deduced. Finally, the feasibility of the proposed integrated control strategy is validated by simulation and experiment.