Single-Phase 9L Switched-Capacitor Boost Multilevel Inverter (9L-SC-BMLI) Topology

The boosting factor has become a vital feature for a multilevel inverter to be connected with the low voltage PV system. In this paper, an inverter topology with 9 levels has been introduced. With the use of 10 switches and one switched capacitor unit, the proposed 9L-SC-BMLI has achieved nine different voltage states, and it has twice voltage gain. Without any auxiliary circuits, the voltage of the floating capacitor can maintain self-balanced. The additional feature of the proposed 9L-SC-BMLI has been the lower number of switches, voltage stress of reduced magnitude, and inherent polarity reversal of the output voltage without any H-bridge. The 9L-SC-BMLI has been controlled using the PD-PWM technique, i.e., phase-disposition pulse width modulation technique. In order to show the merits of the 9L-SC-BMLI, a detailed comparative study has been provided in the paper with several similar topologies. A number of simulation results have been provided in the paper with different working environments, and these results have been validated with the real-time results accomplished from a laboratory prototype.