Nine‐level voltage‐doubler bi‐polar module for multilevel DC to AC power conversion

Abstract

A major disadvantage of two-stage topologies of switched capacitors based multilevel inverters is the use of H-bridge switches which endure high peak-inverse-voltage (PIV). In such topologies, the H-bridge stage is preceded by a levelgeneration stage which synthesises unipolar voltage levels. In this work, a bi-polar module is proposed which can synthesise nine levels at the AC terminals with a single DC input. The proposed module uses power switches with PIV equal to that of the input DC source. Use of switched capacitors in each of the proposed module enables a voltage gain of two. Such bi-polar voltage-doubler modules can be easily connected in a cascaded fashion to increase the number of levels, without involving Hbridge switches. Working modes of the module ensure that the capacitors are self-balanced. A complete analysis of the proposed module is presented. Also, experimental results are presented for validation. In addition, a comparison with other topologies has been presented.

An extendable single‐input reduced‐switch 11‐level switched‐capacitor inverter with quintuple boosting factor

“…According to Table 3, the efficiency of the proposed basic topology in its operating output power range varies from 91% to 95.6%. Based on reported efficiencies, the topologies presented in [12, 15, 17] have higher efficiency, where the reported efficiency of [16, 18, 19] is less than that of the proposed basic topology. The reported efficiencies for [10, 14] are almost the same range of proposed basic topology.…”

“…In [16], a 7-level triple-gain inverter has been presented that uses a single DC source, 2 flying capacitors, 11 switches (12 MOSFETs), and a bidirectional one. Another single-source 9-level inverter has been introduced in [17] that produced a double boosting factor by 2 floating capacitors and 10 switches (11 MOSFETs). One switch is bidirectional.…”

A novel nine‐level boost inverter with a low component count for electric vehicle applications

“…Peak inverse voltage (PIV) of these topologies is equal to . However, the boosting factor of 20,21 is unity per capacitor and 22,23 is 0.5 per capacitor. Furthermore, these require more capacitors and semiconductors to extend the inverter circuit for other levels.…”

“…To address issue of double staged boost MLIs, authors in Reference 20‐23 have developed single stage inverters. These topologies do not require H‐bride to produce zero/negative levels.…”

A Survey on Reduced Switch Count Multilevel Inverters

“…25: Single-stage switched-capacitor unit (S 3 CM) topology.Motivated by the objective of S 3 CM, reduce device count and increase number of levels, various compact single-stage configurations are reported[156][157][158][159]. In[156,157], a nine-level boost topology with voltage gain two is reported. This configuration is similar to Fig.25, but the device count reduced by one, which leads to reduction in TSV to 10E.…”