Based on the switched-capacitor (SC) principle, a seven-level inverter is proposed, which can synthesize seven levels containing a single dc source. Moreover, it can further generate more levels by a cascaded extension. Meanwhile, the proposed topology does not require any sensor due to the use of SC technology. Furthermore, the capacitor voltage is self-balanced without utilizing the complicated control strategy and additional control circuits. The phase disposition pulsewidth modulation is adopted to reduce the total harmonic distortion. The topology can generate different levels with a wide range of modulation index. In addition, the topology can also work in overmodulation. Compared with the traditional SC multilevel inverter, the absence of H-bridge makes low-voltage stress in proposed topology. The voltage stress of all switches is not more than the input voltage. Operational principles, modulation strategy, and voltage stress analysis are discussed. Simulation and experiment are conducted in low power to verify the feasibility of the proposed topology.

中文翻译：

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具有自平衡和低压应力的七电平逆变器

基于开关电容器（SC）原理，提出了一种七电平逆变器，该逆变器可以合成包含单个直流电源的七电平。而且，它可以通过级联扩展进一步生成更多级别。同时，由于使用了SC技术，因此建议的拓扑不需要任何传感器。此外，电容器电压是自平衡的，而无需利用复杂的控制策略和附加控制电路。采用相位配置脉冲宽度调制来减少总谐波失真。拓扑可以生成具有广泛调制指数的不同级别。此外，拓扑还可以在过调制中工作。与传统的SC多电平逆变器相比，由于没有H桥，因此在建议的拓扑结构中会产生低压应力。所有开关的电压应力均不大于输入电压。讨论了工作原理，调制策略和电压应力分析。在低功耗下进行仿真和实验，以验证所提出拓扑的可行性。