A New Self-Balanced Six-Level Switched-Capacitor Inverter

Multilevel inverters are widely used in renewable-energy conversion systems; however, many existing solutions rely on additional DC-DC boost stages, multiple isolated sources, or bulky transformers. This paper proposes a transformerless six-level switched-capacitor inverter supplied by a single DC source. The proposed topology integrates a reduced-switch-count power stage with a switchedcapacitor structure employing floating capacitors and diodes to achieve a voltage boosting gain of 2.5 without using inductive components. The floating-capacitor voltages are naturally balanced by the defined charging and discharging sequence of the switching states, eliminating the need for voltage sensors or auxiliary balancing control. The voltage stress of the switches and floating capacitors in the switchedcapacitor network is limited to the input-voltage level, resulting in a competitive total standing voltage and improved efficiency. The inverter generates a high-quality six-level output waveform with a lower component count compared to conventional switched-capacitor multilevel inverters. Furthermore, extended configurations for higher voltage gains and a three-phase implementation sharing a common dc-link are presented to demonstrate scalability. Detailed operating principles, modulation strategy, and design considerations are discussed. Simulation and experimental results confirm the feasibility and effectiveness of the proposed inverter for low-voltage photovoltaic applications.