Reduction Method of Load Neutral Point Potential Variation for Three-level V-connection Inverter Using Space Vector PWM

Abstract

In this paper, a method that uses Space Vector Pulse Width Modulation (SVPWM) for reducing the load neutral point potential variation of a three-level V-connection inverter is proposed. In the proposed method, by selecting the vectors that have low load neutral point potential to generate the output voltage command value, the variation range of the load neutral point potential of the V-connection inverter can be reduced. In addition, the load neutral point potential variation influences the magnitude of the load's common-mode leaked current. Moreover, this leaked current is dominant in the generation of conduction noise. Therefore, by reducing the variation range of the load neutral point potential, the proposed SVPWM can be considered capable of reducing conduction noise. Then an experimental comparison of the load neutral point potential variation of the proposed method and the conventional method is analyzed. The results confirm the effect of reducing the load neutral point potential variation by using the proposed method.