ABSTRACT

A novel topology of the modular multilevel inverter with the ability to boost the input voltage is proposed in this work. The proposed single-source structure requires neither any external controller nor transformers to balance the voltages of the capacitors. In addition, the output voltage polarity of the inverter is generated inherently with a low switching frequency, making it suitable for both residential and industrial applications. The Nearest Level Modulation (NLM) is applied to control the operation of the inverter. The detailed comparative analysis of the proposed inverter with other inverters indicates that the proposed structure can produce similar voltage levels with a fewer number of elements and less voltage stresses. Moreover, to verify the performance of the proposed converter, a single-phase 13-level prototype was implemented in the laboratory environment and the test results were compared to the simulation ones. The advantages of low harmonic contents with Total Harmonic Distortion (THD) of 6.5% and 92.69% efficiency make the proposed inverter appropriate for applications with a limited number of low voltage sources.

摘要

在这项工作中，提出了一种具有提升输入电压能力的模块化多电平逆变器的新颖拓扑。所提出的单源结构既不需要任何外部控制器也不需要变压器来平衡电容器的电压。此外，逆变器的输出电压极性固有地以低开关频率产生，使其适用于住宅和工业应用。最近电平调制 (NLM) 用于控制逆变器的操作。对所提出的逆变器与其他逆变器的详细比较分析表明，所提出的结构可以产生相似的电压电平，但元件数量更少，电压应力更小。此外，为了验证所提出的转换器的性能，在实验室环境中实现了一个单相13级原型，并将测试结果与仿真结果进行了比较。总谐波失真 (THD) 为 6.5% 和效率为 92.69% 的低谐波含量的优势使所提出的逆变器适用于低压源数量有限的应用。