Controlling the Vienna rectifier using a simplified space vector pulse width modulation technique
In this thesis, a simplified Space-Vector Pulse-Width-Modulation (SVPWM) technique for the Vienna rectifier is introduced to reduce the computational burden, the switching losses and the Total-Harmonic-Distortion (THD). Furthermore, the robustness of this modulation technique is tested under various faults through a 70 kW MATLAB/Simulink model and the results are validated through 1.2 kW prototype. The results reveal that the simplified SVPWM provides a low THD, unity Power-Factor (PF) and effective capacitor voltage balancing even after extreme faults. This study introduces a multilevel Power-Factor-Correction (PFC) converter in a 2-stage configuration. The first stage is the Vienna rectifier which has a high boosting ratio. To overcome this issue, a high efficiency 4-switch converter is cascaded with the Vienna rectifier. This converter employs storage-less passive components and provides a Zero-Current-Switching (ZCS) for all of its switches. A description of the converter is first introduced followed by the simulation results.