This article presents a modular switched-capacitor multilevel inverter which uses two capacitors and a single dc source to obtain triple voltage gain. It is worth noting that the inherent inversion capacity removes the H-bridge, which can efficaciously diminish the voltage stress of switches, and the maximum voltage stress (MVS) on devices is kept within 2Vdc. Additionally, the proposed topology is able to integrate inductive load, and the capacitor voltage self-balancing can be achieved. Moreover, the modular structure also has an expandable topology which can generate more levels and raise the voltage gain by using multiple switched-capacitor units, meanwhile the voltage stress on power switches can be kept within 2Vdc. Furthermore, comprehensive analysis and comparison with other multilevel inverters have been implemented to certify the superiority of the proposed topology. Finally, the steady-state and dynamic performance of the proposed topology is examined through a seven-level inverter prototype, the validity and practicability of the topology are verified by simulations and experiments.

Multilevel inverters (MLIs) play an important role in research on renewable energy conversion. However, in traditional designs, the high voltage stress of switching devices and the large number of switches limit the wide application of the inverter. In order to ameliorate these problems, this paper proposes a switched-capacitor multilevel inverter (SCMLI). When compared with traditional MLIs, the proposed SCMLI utilizes a switchedcapacitor structure, where the capacitors can achieve voltage self-balancing without auxiliary methods. Thus, it permits changes of the positive and negative polarity of the output level without the need for an H-bridge. In addition, with the augment of the level in the expanded SCMLI structure, the maximum blocking voltage can be kept constant. To show the advantages of the proposed structure, an extensible single dc source five-level SCMLI prototype has been built. Through a comparative analysis with different topologies, this paper also presents the advantages of the proposed topology in terms of the output voltage gain, number of output levels, and voltage stress. Finally, the correctness and feasibility of the proposed inverter are validated by extensive experiments.