The paper presents a novel approach for low-order harmonic power mitigation in a single-phase, three-level DC/AC inverter. Traditionally, a bulk electrolytic capacitor is used at the DC bus to eliminate the low-frequency ripple. However, owing to the low-frequency components and large capacitor, this technique is not a practical solution. A new active filtering technique using a ripple port without an external circuit or additional switching power devices is proposed. The new technique harnesses the superior features of switched-capacitor circuits to create a topology with a multiport structure. As a result, a small DC-link capacitor can be applied by controlling the modulating reference waveforms between the different ports of the inverter. Additionally, the use of fast wide bandgap devices will allow for smaller passive components, and with high operating temperatures, the heat sink size can be greatly reduced. The theoretical analysis of the ripple reduction technique is explained in detail. The prototype was built in a laboratory, and experimental results are provided.

本文提出了一种在单相三电平 DC/AC 逆变器中降低低次谐波功率的新方法。传统上，在直流总线上使用大容量电解电容器来消除低频纹波。然而，由于低频元件和大电容，这种技术不是一个实用的解决方案。提出了一种使用纹波端口的新型有源滤波技术，无需外部电路或额外的开关功率器件。新技术利用开关电容器电路的优越特性来创建具有多端口结构的拓扑。因此，通过控制逆变器不同端口之间的调制参考波形，可以应用一个小的直流母线电容器。此外，使用快速宽带隙器件将允许使用更小的无源元件，并且在高工作温度下，散热器尺寸可以大大减小。详细解释了纹波减少技术的理论分析。样机是在实验室中建造的，并提供了实验结果。