This paper proposes a method to reduce the lowfrequency neutral-point voltage oscillations. The neutral-point voltage oscillations
are considerably reduced by adding a time offset to the three-phase turn-on times. The proper time offset is simply calculated
considering the phase currents and dwell time of small- and medium-voltage vectors. However, if the power factor is lower, there is
a limitation to eliminate neutral-point oscillations. In this case, the proposed method can be improved by changing the switching
sequence properly. Additionally, a method for neutral-point voltage balancing is also proposed. The change in switching frequency
by the proposed method and its effects on the outputs are negligible. Simulation and experimental results verify the validity and
feasibility of the proposed strategy.
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