This paper deals with the analysis of the input dc-link voltage ripple in multilevel inverter based on H-bridge and level doubling network (LDN). The LDN is basically a half-bridge fed by a floating capacitor, with voltage self-balancing capability, recalling the concept of a flying capacitor configuration. The amplitude of the LDN voltage ripple is analytically determined considering both the low-order and the switching harmonic components. In particular, peak-to-peak distributions of voltage ripples over the fundamental period are analytically determined, making possible the design of dc-link capacitor relying only on the dc-voltage ripple requirements. The case study makes reference to negligible switching ripple in the output current. It well represents either grid connection or passive load having almost sinusoidal currents. Numerical simulations carried out by MATLAB/Simulink and a complete set of experimental verifications are given to confirm the theoretical developments.

中文翻译：

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H 桥多电平逆变器的电平倍增网络 (LDN) 单元中的输入电流和电压纹波分析

本文涉及基于 H 桥和电平倍增网络 (LDN) 的多电平逆变器中输入直流链路电压纹波的分析。LDN 基本上是一个由浮动电容器供电的半桥，具有电压自平衡能力，让人想起飞跨电容器配置的概念。LDN 电压纹波的幅度是通过分析确定的，同时考虑了低次谐波分量和开关谐波分量。特别是，分析确定了基本周期内电压纹波的峰峰值分布，使得仅依赖于直流电压纹波要求的直流母线电容器的设计成为可能。案例研究参考了输出电流中可忽略的开关纹波。它很好地代表了具有几乎正弦电流的电网连接或无源负载。