ABSTRACT
In this paper, a novel cascaded seven-level inverter topology with a single input source integrating switched capacitor techniques is presented. Compared with the traditional cascade multilevel inverter (CMI), the proposed topology replaces all the separate dc sources with capacitors, leaving only one H-bridge cell with a real dc voltage source and only adds two charging switches. The capacitor charging circuit contains only power switches, so that the capacitor charging time is independent of the load. The capacitor voltage can be controlled at a desired level without complex voltage control algorithm and only use the most common carrier phase-shifted sinusoidal pulse width modulation (CPS-SPWM) strategy. The operation principle and the charging-discharging characteristic analysis are discussed in detail. A 1kW experimental prototype is built and tested to verify the feasibility and effectiveness of the proposed topology. A SINGLE DC SOURCE CASCADED SEVEN-LEVEL INVERTER INTEGRATING SWITCHED CAPACITOR TECHNIQUES
CIRCUIT DIAGRAM
