A Three-Phase Neutral-Point Clamped AC/DC Converter Based On Modified Space Vector Modulation for Power Quality Improvement

The generation of harmonics and reactive power flow in a power system is greatly influenced by the widespread use of power electronic converters in addition to other sources of harmonics and reactive power. This paper presents a space-vector modulated three-level neutral-point clamped converter in rectification and regeneration modes for the power quality improvement. Specifically, this paper identifies the unbalance generated by different conduction states and proposes a very simple method to achieve balanced capacitor voltages by using the redundant switching vectors, depending on the polarity of the voltage difference and the direction of power flow. The modeling, analysis and control of the converter using space vector modulation is presented in this paper. The analytical study is validated by the simulation results of the converter.