Seven‐level triple boost self‐balanced switched‐capacitor inverter

Abstract

Switched‐capacitor multi‐level inverters (SCMLIs) have become more popular in recent years due to their unique advantage of voltage boosting capability. A seven‐level triple boost SCMLI is proposed in this paper. The proposed topology consists of 10 switches, one diode, three self‐balanced capacitors, and a DC source. The voltage stress on each switch is less than or equal to twice the input DC source voltage. Further, 4 out of 10 switches are switched at the fundamental frequency. The maximum conducting switches at each level is less than or equal to 4. The capacitors are self‐balanced without using any voltage sensors or external circuits. A detailed comparison has been given with the existing seven‐level triple boost SCMLI to show the superiority of the proposed topology. The seven‐level triple boost SCMLI is simulated using MATLAB/SIMULINK tool. The proposed model is verified at low‐ and high‐frequency switching, sudden changes in output load, and different modulation index values. The results are verified experimentally with the help of a prototype model developed in the laboratory using dSPACE 1104.

Seven‐level single‐source switched capacitor inverter with triple boosting capability and high reliability

“…To understand the implementation of the cost of the topology parameter, CF/N L is being calculated and shown in Table 3. The proposed topology has a CF level of 0.75, while topologies presented in the literature 4,13,[15][16][17]25 have higher CF level parameters as compared with the proposed topology. Therefore, this topology is found to be cost-effective as compared with these existing topologies.…”

“…The paper in Yarlagadda and Verma 4 has used the same number of switches but the number of capacitors used was 3, whereas the number of capacitors used to provide the same boosting is 2 for the proposed topology. The reduction in the number of capacitors increases the efficiency of the converter at high power levels, and less charging current is drawn from the source.…”

“…It has merits over two-level inverters in terms of better output voltage quality, reduced THD and higher voltage levels, and lesser voltage stress on switches.Due to these advantages, they have many application areas like solar photovoltaic (PV) systems, drives, electric vehicles, and HVDC systems. [1][2][3][4] Conventionally, a two-stage conversion process was used to boost and convert the DC voltage to AC voltage using an H-bridge inverter. The boost converter is used to step up the voltage.…”

“…These multisource topologies are more practical for use in renewable energy applications. The converter in Yarlagadda and Verma 4 has used two isolated sources to form 11‐level converters. The converter has good features like common ground, but the voltage stress levels are high due to the use of an H‐bridge.…”

A single‐phase seven‐level buck‐boost common ground transformerless inverter for grid‐connected photovoltaic system

“…However, all the above topologies are limited to produce a gain of 1.5 times, which may not replace the requirement of a front‐end boost converter. To resolve the above issue, Yarlagadda et al 21 have proposed a 7L SC‐MLI with three times boosting along with self‐balancing of capacitors. However, the topology has an issue of leakage current due to the absence of a common ground connection, which may not be used directly for the PV applications.…”