Analysis of the Vienna Rectifier under Nonunity Power Factor Operation

The Vienna rectifier is an attractive topology due to the three-level voltage generation and its simplicity compared to other converter solutions. The Vienna rectifier generates voltage and current waveforms with low distortion under unity power factor operation. However, when the reference voltages and the grid currents are not in phase, the output voltages become distorted and therefore the grid currents as well. This paper evaluates the distortions produced due to nonunity power factor operation in the Vienna rectifier. It also discusses on possible solutions to mitigate the problem and evaluates their effectiveness and limitations.