An eleven-level modified neutral-point-clamped (11L-MNPC) inverter with single input DC source for renewable energy source applications

Abstract In this article, an eleven-level modified neutral point clamped (11L-MNPC) inverter is presented. The proposed topology achieves a voltage gain of 2.5, which minimizes the DC-link voltage requirement by 80% as compared to the classical NPC inverter. The circuit comprises eight unidirectional switches with antiparallel diodes, two bi-directional switches, and two switched-capacitors (SCs). The voltages across the SCs and DC-link capacitors naturally settle at their requisite values without the need of any external circuitry or sensors. The proposed MNPC inverter is compared with existing NPC-based topologies, highlighting its advantages in terms of number of switches, number of capacitors, voltage gain, total standing voltage (TSV), etc. The proposed topology can work for a wide range of modulation indexes and inductive loads. The operation of the inverter is also validated for three-phase grid interconnection. The results reveal that the proposed multilevel inverter (MLI) has both active and reactive power handling capabilities, which makes it suitable for grid-tied renewable energy source applications.