Generation of Optimal Switching Angle for Nine Level Cascaded H Bridge MLI Using Most Valuable Player Algorithm

Vijaya Anand N, Hema Latha J, G Devadasu, Kumar C G Devadasu, Kumar C

doi:10.17762/turcomat.v12i6.4442

Vijaya Anand N, Hema Latha J, G Devadasu, Kumar C G Devadasu, Kumar C

Open Access

https://doi.org/10.17762/turcomat.v12i6.4442

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Abstract

Distributed generation (DG) sources often interfaced with grid by a Cascaded H-bridge multilevel inverter with a remote D.C source. The interface inverter has to adapt voltage on the either side of the grid and DG source while it has a control of active and reactive power exchange. The inverter terminal voltage is maintained based on frequency switching technique. However, in applications like micro grids are based on quality of output voltage at the point of common coupling. The present paper discusses an optimal frequency switching methodology that generates optimal fringing angle based on an evolutionary computing technique while maintaining the voltage level at PCC with a reduced harmonic distortion. Efficacy of the proposed method is illustrated by simulating a 9-level cascaded H bridge in MATLAB environment.

Highlights

Many of the high-power applications are developed based on Multi Level Inverters (MLI)
The PWM technique used for switching the devices is selective harmonic elimination technique
In this paper a nine level CHBMLI is presented with an objective of improving voltage quality at Point of Common Coupling (PCC) and reduced harmonic levels

Summary

Introduction

Many of the high-power applications are developed based on Multi Level Inverters (MLI). SHEPWM switching method proposed for the grid connected multilevel inverters is based on injecting the specific harmonic by one inverter and absorbing the same by another inverter so that specific harmonics are eliminated at PCC in view of voltage quality. This method may result in reduced line voltage, THD at PCC but does not meet the standard limit of grid code. Each DC link is connected to a single phase full-bridge inverter and can generate three different voltage outputs, +Vdc, 0 and -Vdc. each level’s full-bridge inverter is connected in succession such that the synthesized voltage waveform is the sum of all of the individual outputs

Selective Harmonics Elimination

Simulation Results

Conclusion