Voltage Boosting Technique for Switched Capacitor Based Cascaded H-Bridge Multilevel Inverter

Cascaded Multilevel Inverter (CMI) in photovoltaic (PV) systems calls for separated PV modules in each H-bridge cell. In turn, each PV module requires a dc-dc converter to make the MPPT process easier. Thus, the CMI in PV systems requires a complicated control system to control the isolated dc sources. Since the switched capacitor-based CMI (SC-CMI) needs only one dc source, it can be a suitable inverter for PV systems. In this inverter the capacitors are charged through the dc source and a charging circuit. However, the main problem in this inverter is voltage reduction under heavy loads. To tackle the issue, this paper proposes a voltage boosting technique for the SC-CMI with PV systems, which considerably increases the voltage gain. In the proposed system, the capacitors are all charged through one dc source, so only one controlling mechanism is needed to control the dc link. Simulation and experimental outcomes are provided to prove the effectiveness of the suggested circuit.