A Single-Stage Neutral Point Clamp Inverter with Reduced Voltage Stresses on Power Elements

Abstract

In this paper, a topology incorporating the DC-link type quasi-switch boost network with the traditional three-level neutral point clamped inverter is presented. The third harmonic injection method is proposed to provide some benefits such as: enhancing the modulation index or improving the voltage gain. Moreover, the stress voltage on power devices like capacitors, diodes, and switches is decreased significantly. The mathematic analysis is detailed to produce the equations output voltage for the proposed converter. The comparison between the proposed topology to conventional quasi-switch boost neutral point clamped inverter topology is carried out. Simulation and experimental results are conducted to verify the accuracy of inverter operating theory.