A Multi-Cell 21-Level Hybrid Multilevel Inverter Synthesizes a Reduced Number of Components With Voltage Boosting Property

Alaaeldien Hassan,Xu Yang,Wenjie Chen

doi:10.1109/access.2020.3044268

Alaaeldien Hassan, Xu Yang + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.3044268

Copy DOI

Abstract

A multi-cell hybrid 21-Level multilevel inverter is proposed in this paper. The proposed topology includes two-unit; an H-bridge is cascaded with a modified K-type unit to generate an output voltage waveform with 21 levels based only on two unequal DC suppliers. The proposed topology’s advantage lies in the fine and clear output voltage waveforms with high output efficiency. Meanwhile, the high number of output voltage waveform levels generates a low level of distortion and reduces the level of an electromagnetic interface (EMI). Moreover, it reduces the voltage stress on the switching devices and gives it a long lifetime. Also, the reduction in the number of components has a noticeable role in saving size and cost. Regarding the capacitors charging, the proposed topology presents an online method for charging and balancing the capacitor’s voltage without any auxiliary circuits. The proposed topology can upgrade to a high number of output steps through the cascading connection. Undoubtedly this cascading will increase the power level to medium and high levels and reduce the harmonics content to a neglectable rate. The proposed system has been tested through the simulation results, and an experimental prototype based on the controller dSPACE (DS-1103) hardware unit used to support the simulation results.

Highlights

MLIs gained wide fame as a member of the family of the DC/AC converters, and make a revolution in the industrial field
The performance of the proposed 21L hybrid MLI topology has been verified based on two ways; firstly, the simulation verification performed through the simulation software (MATLAB /SIMULINK) environment and the simulation validation have applied for the single unit and the cascaded connection system
The work in this paper presented a hybrid multilevel inverter that consisted of a series connection between two units

Summary

INTRODUCTION

MLIs gained wide fame as a member of the family of the DC/AC converters, and make a revolution in the industrial field. The proposed MLI topology ensures a reduced number of switching devices, diodes, and DC sources to generate the desired output voltage waveform levels. Figure. indicates the comparative studies for the number of switches, number of capacitors, number of DC suppliers, and the number of drives circuits in terms of the number of levels For these statistics, the proposed topology presents a perfect performance in reducing the number switching devices which reflects in reducing the level of losses and switch stress and enhances efficiency. The presented data confirmed the superiority of the proposed topology over the other MLIs topologies when it achieves the most optimal design to generate the desired number of levels in the output voltage waveform with a reduced number of components which ensures a reduction in the total power losses and enhances the system reliability. MLI topology achieves a stepping up for the input voltage compared to almost of the MLIs topologies in the comparison except for the references [10, 51],[49] which records a step-up ratio slightly higher than the presented topology, but the proposed topology still beats these references in the other performance parameters that were mentioned earlier

POWER LOSSES AND CAPACITANCE

RESULTS AND DISCUSSIONS

SIMULATION RESULTS

EXPERIMENTAL RESULTS

CONCLUSION