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Switched-capacitor-based multilevel inverters for boost-type dc-ac power conversions usually exhibit a trade-off between the switch count and switch-voltage rating, i.e., a reduction of one necessitating an increase of the other. Such a dilemma is well addressed in this paper by proposing a novel single-phase nine-level inverter based on a switched-capacitor network with a single switch. The proposed inverter then reduces the number of switches while generating a boosted dc-link voltage. A unique six-switch full-bridge cooperating with a lowfrequency half-bridge further steps-up the output voltage with a quadruple gain. The voltage stresses on the power devices are, however, maintained low even under the boosted high output voltage, as all the switches/diodes can be clamped to any of the low-voltage capacitors. Consequently, low-voltage power devices can be utilized, reducing the overall power loss. Detailed theoretical analysis, calculations, and design considerations of the proposed inverter are provided. Comparisons with the prior-art inverters illustrate its advantages. Simulations and experimental tests on a 1-kVA inverter prototype verify the above-claimed benefits.

Multilevel inverters in renewable applications usually require a high-voltage DC link fed by a front-end DC-DC boost stage. Such a two-stage power conversion however increases the switch count, leading to higher costs and power losses. To lower the number of switches, this letter proposes a six-switch inverter, capable of generating a seven-level voltage and a triplevoltage boost. Both features are achieved with only four switches operating at a high frequency, while clamped by low-voltage capacitors. The remaining two switches must however endure higher voltage stresses, but fortunately operate at a much lower frequency. Overall switching losses of the inverter are thus significantly reduced. Besides, the inverter shares a common ground between its DC input and AC output, which theoretically helps to eliminate leakage current, if powered by photovoltaic sources. Operating principles of the inverter have been described and verified through experiments with an 800-W prototype.

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