A Single-Source Switched-Capacitor-Based Step-Up Multilevel Inverter With Reduced Components

Abstract

Switched-capacitor-based multilevel inverters (SC MLIs) have received a great deal of interest that reduces the dc source requirement and improves the power quality. However, multiple dc sources and the requirement of a large number of switches to generate a high-quality boost output are the fundamental issues in the SC MLIs. This article presents a step-up 17-level SC MLI using reduced number of switches, three capacitors, and a single dc source. The steady-state voltage across the capacitors is maintained in the ratio 1:2:0.5 that contributes to quadruple boosting ability without using any auxiliary capacitor voltage balancing circuit. Besides, lower switch count in the conduction path and operation of 50% of the switches at fundamental frequency ensures total power loss reduction in the proposed circuit. A comparative assessment with recently developed 17-level MLIs in terms of the number of components, gain, stress, and cost factor elucidates the advantages of the proposed MLI. After a detailed circuit analysis and loss evaluation, simulations are performed to verify the step-up and inherent balancing features of the proposed MLI. Further, using both the fundamental frequency and high-frequency switching techniques, extensive experimental test results are presented under different transient conditions to validate the operational feasibility of the 17-level prototype. Index Terms-Multilevel inverter (MLI), reduced components, self-voltage balance, single-source, switched-capacitor (SC), voltage gain. I. INTRODUCTION D EVELOPMENT of multilevel inverters (MLIs) has been a recent trend for a variety of low-, medium-, and highpower applications [1]-[5].

Switched-Capacitor Multilevel Inverters: A Comprehensive Review

“…Having taken these SC/FC-based hybrid techniques into account, the front-end SC unit, which is in charge of delivering a multiple-dc-link boosted voltage to the output, can be replaced with any of the generalized SCCs described earlier to develop more number of inverter output voltage levels with a single input dc-source design. Regarding this and considering the binary asymmetrical charging operation of the capacitors described in [45]- [47], a 17L hybrid inverter with quadruple voltage gain and 12 power switches is introduced in [153].…”

Design and Implementation of Asymmetrical Multilevel Inverter With Reduced Components and Low Voltage Stress

“…As a result, the cost factor is determined using the following equation ( 17) [28]. 𝐶𝐹 = (𝑁 𝑆 + +𝑁 𝑔𝑑 + 𝑁 𝐷 + 𝑁 𝐶 + 𝛼𝑇𝑆𝑉 𝑃𝑈 )×𝑁 𝐷𝐶 (17) The weight coefficient α is always larger than 1 and less than unity. The cost factor is estimated in the developed 33-level MLI with the value of 0.…”

“…The power loss of the power electronic switches is the combination of conduction and switching losses. These are calculated based on the approach provided in [17] may be assessed for the developed topology. Conduction losses occurs when semiconductor devices conduct at the on-states owing to voltage drop.…”

“…The selective harmonic elimination modulation is used to produce the pulses to the switches for getting the desired output. In [16] and [17], a switched capacitor based MLI is proposed, which consist of high gain and energized with a single DC source. The proposed MLI has reduced switch count and has superior performance and cost-effective.…”

A New Reduced Switch Seven-Level Triple Boost Switched Capacitor Based Inverter

“…Therefore, switched capacitor technique was developed by the researchers to get the greater number of voltage levels and high gain with only one DC source. In this technique, the capacitors are charged by connecting them in parallel to the DC source and discharged to the load in series with the DC source to get higher voltage levels [4], [5].…”