Comparison of Level-Shift and Phase-Shift Modulation in ۳-level NPC Inverter

This paper compares the performance of three-level NPC (neutral point clamped) multi-level voltage source converters using Level-Shifted modulation method with in-phase regulation (In-Phase Regulation and Phase Opposition Disposition) and Phase-Shifted modulation. The main objective of this study is to comprehensively analyze these three modulations in terms of harmonic distortion reduction, phase and line voltage analysis, input and output current. The comparisons were performed through simulation in MATLAB/Simulink. The results show In three-level NPC inverters, the Modulation methods have distinct characteristics. Phase Shifted Modulation delivers the best waveform quality and the lowest THD for both voltage and current, making it ideal for high-performance applications. IPD has moderate THD and simpler implementation, suitable for applications with less critical harmonic requirements. POD reduces common-mode voltage but often shows the highest THD in both voltage and current due to uneven harmonic cancellation.

کلیدواژه ها:

NPC (Neutral Point Clamped) inverter ، In-Phase Regulation (IPD) ، Phase Opposition Disposition (POD) ، Level-Shifted ، Phase-Shifted modulation (PSM)