A Generalized Cascade Switched-Capacitor Multilevel Converter Structure and its Optimization Analysis

Intl J of Energy Research

Siwakoti

et al. 2021

This article proposes a single-phase double-source 27-level basic inverter structure based on Switched-Capacitors (SCs) circuit for renewable energy sources.The extendibility, low Blocking Voltage (BV) on semiconductors, step-up capability, and self-voltage balancing of capacitors are the main advantages of the suggested basic structure. Using double H-bridges to generate bi-polar voltage waveform, the blocking voltage on the semiconductors limit to only 0.692 V o,max . The Average of Normalized Blocking Voltage (ANBV) on semiconductors of basic topology is only about 33.52%. Two extended structures have been presented with higher output voltage steps and boosting factors. The first extended topology composed of two (right and left) Generalized Switched Capacitor based Modules (GSCMs), results in reduced sources (only 2), increased steps, low BV on semiconductors, and boosting factor of 2 n (n: number of SC Cells). The second extended topology can be realized by applying more cascaded Switched-Capacitor Modules (SCMs), which benefits from quadruple-gain and increased levels (9 m , m: number of cascaded modules).The suggested topologies properly supply the zero or low power-factor load types. The superiority of proposed configurations over recently presented similar structures has been compared and verified. The experimental outcomes of the basic topology have also been provided to validate its correct operation.

Section: Comparative Analysismentioning

confidence: 99%

A boost type switched‐capacitor multi‐level inverter for renewable energy sources with Self‐Voltage balancing of capacitors

Deliri

Intl J of Energy Research

Siwakoti

et al. 2021

“…In [9][10][11], the application of capacitors has only decreased the number of sources (unity gain). But in [12][13][14][15][16][17][18][19][20][21][22][23][24], the enhanced gain has also been reported besides reduced source count. The charge balancing of capacitors is the main challenge of SCBM-LIs [25].…”

Section: Introductionmentioning

confidence: 99%

Generalized diamond‐type single DC‐source switched‐capacitor based multilevel inverter with step‐up and natural voltage balancing capabilities

Deliri

Siwakoti

et al. 2021

IET Power Electronics

This paper proposes a diamond‐shaped high step‐up switched‐capacitor based basic multilevel inverter topology. The basic switched‐capacitor (SC) stage consists of 2 active switches, 2 diodes, and 2 capacitors. Using a single DC source with the unfolding circuit (10 switches, 5 capacitors, and 5 diodes) results in the production of 17 voltage‐steps at the output with the gain of up to 8 times of the input voltage. By extending the diamond‐shaped switched‐capacitor stages, higher voltage levels and voltage gains can be possible. The suggested topology employs two half‐bridges (instead of a full‐bridge) to produce positive, zero, and negative steps, which reduces the Voltage Stress (VS) on two output switches and consequently reduces Total Voltage Stress (TVS). In addition, the natural voltage balancing of capacitors eliminates the need to an additional control circuitry and consequently reduces the total converter size, complexity, and cost. In addition, modularity, scalability, low voltage ripple on capacitors, low total voltage stress, high power quality, and capability of supplying low/medium power factor (R‐L) loads are some of the merits of the proposed topology. The low Cost Function (CF) obtained in the comparison section as well as experimental results verifies the advantages of the proposed topology.

“…5 These topologies benefit from large voltage gain and numerous levels. Due to developed H-bridge based nature of, [28][29][30] two switches tolerate the VS of V o,max .…”

Section: Introductionmentioning

confidence: 99%

“…The number of switches tolerating V o , max in 26,27 are 0 and 4, respectively. Consequently, the 27 suffers from large total VS. The 28–30 present three novel double‐input developed H‐bridge based topologies employing switched‐capacitor units instead of DC sources in 5 . These topologies benefit from large voltage gain and numerous levels.…”

Section: Introductionmentioning

confidence: 99%

An extendable asymmetric boost multi‐level inverter with self‐balanced capacitors

Karimi

Kargar

2021

Circuit Theory & Apps

This paper proposes a basic asymmetric boost 35-level inverter topology that can be extended to earn higher gains and levels. The proposed structure benefits from following advantages: extendibility, voltage boosting capability, natural voltage balancing of capacitors, low average voltage stress on semiconductors and large ratio of number of steps to components. The impulse charging current of capacitor(s) is suppressed by small inductor(s), which is bypassed by a diode during discharging mode. The low magnitude (accordingly