A Single-Phase Boost Switched-Capacitor Seven-Level Inverter With Eight Switches

This paper proposes a seven-level boost switched-capacitor inverter utilizing only eight active switches (8S7L-BSCI). The study addresses several limitations of conventional SC-MLI configurations, which often require multiple DC sources, lack inherent capacitor voltage balancing, or involve a high semiconductor count leading to increased switching losses. To overcome these challenges, the 8S7L-BSCI integrates a two-stage switched-capacitor (SC) network with a full H-bridge, enabling triple voltage boosting and seven-level output generation without additional DC sources, transformers, or front-end boost converters. The objective of this work is to develop a single-source inverter with high voltage gain, intrinsic capacitor-voltage balancing, and reduced device voltage stress. As a result, the proposed inverter is well suited for low-voltage PV systems and energy-storage applications. The main contribution lies in proposing a simplified SC-MLI architecture in which only two MOSFETs operate at high frequency while the remaining switches function at the line frequency, thereby reducing switching losses and control complexity. The paper presents a detailed explanation of the operating principles of the two-stage SC network, the Boolean-logic-based PWM strategy, and comparative evaluations with existing topologies. Simulation and experimental results from a hardware prototype of approximately 330 W confirm the feasibility of the proposed inverter, demonstrating stable operation with an efficiency of about 95% ± 1.3%. Furthermore, the inverter delivers high-quality output with harmonic distortion maintained below 1% under inductive loading conditions.