Asymmetric cascade multilevel inverter with self‐balanced switched‐capacitor unit and single source. Issue 15 (21st September 2020)

• Record Type: Journal Article
• Authors: Ye, Yuanmao; Lin, Mingliang; Wang, Xiaolin
• Is Part Of: IET power electronics. Volume 13:Issue 15(2020)
• Page Start: 3254
• Page End: 3262
• Publication Date: 2020-09-21
• Subjects: invertors -- switched capacitor networks -- switching convertors -- bridge circuits -- cascade networks; voltage stress -- SC units -- asymmetric feature -- voltage intervals -- single dc source -- fewer components -- capacitors -- output levels -- output voltage -- switching loss -- nearest level control -- equal area criterion -- 13‐level output -- asymmetric cascade multilevel inverter -- switched‐capacitor unit -- single‐source cascaded H‐bridge multilevel inverter -- self‐balanced series -- SC unit -- asymmetrical cascaded MLI; Power electronics -- Periodicals; 621.31705
• DOI: 10.1049/iet-pel.2019.1098
• Languages: English
• ISSNs: 1755-4535

Abstract

Abstract : The technique of single‐source cascaded H‐bridge multilevel inverter (MLI) has been reported in previous works. In this study, a self‐balanced series/parallel switched‐capacitor (SC) is introduced to further develop this type of MLIs to generate more output levels. Each cascaded H‐bridge is fed by an SC unit. All components in each SC unit withstand the same voltage stress, but different SC units address different voltages. With this asymmetric feature, different H‐bridges are responsible for providing levels with different voltage intervals so that the cascaded MLI can generate numerous levels with a single dc source and fewer components. Compared with the conventional asymmetrical cascaded MLIs, just a single dc source is required, capacitors' voltages are balanced automatically, high boosting ability and more output levels are achieved with SC technique in the proposed MLIs. To synthesise the output voltage as close as possible to sinusoidal shape but with less switching loss, comparative analysis of nearest level control and equal area criterion is provided to modulate the proposed MLI with 13‐level output. Experimental results demonstrate that the proposed MLI has high efficiency and low harmonics.