In this paper, a step-up seven-level inverter supplied by a single DC source suitable for renewable energy application is presented. Forming the desired output is realized by charging capacitors and synthesizing them based on switched-capacitor concept. This structure is praised for the ability of sensor-less voltage balancing of the capacitors, reducing control complexity to produce a bipolar staircase waveform. It also benefits from regenerative performance, avoiding unwanted capacitors overvoltage. Phase Disposition Pulse Width Modulation (PD-PWM) technique is utilized to control the circuit operation. Furthermore, a comparison with other recent topologies reveals that losses, number of semiconductor devices, and gate driver circuits are reduced. Theoretical analysis is verified through a laboratory prototype implementation. Experimental results under various types of loads approve the performance of the proposed inverter and validity of the design. Finally, maximum experimental efficiency of 94.3% (115 V, 250 W load) was reached.

the necessity of using several components in multilevel inverters jeopardizes the reliability of their operation. Hence, the aim of this research is to propose a novel single-phase fault-tolerant topology based on switched-capacitor concept to ensure robustness of the converter in the occurrence of a fault. The proposed single source converter steps up the input voltage seven times with a simple control strategy. Fault Tolerance of the converter is achieved by considering multiple fault cases and providing several redundant switching schemes concerning the type and location of failure. Each switching scheme is designed in a way to ensure the tolerability to both single and multiple open/short circuit failure. Also, self-voltage balancing of the capacitors, as well as the same amount of voltage levels and amplitude in the output is guaranteed. Experimental analysis is carried out, and the results confirm the viability of the proposed inverter under normal and post-fault operating modes.

No abstract