Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement

This study presents a proposed symmetric and asymmetric multilevel inverter topologies using reduced number of switching devices (RNSD) structure for high power density achievement. Principally, asymmetric multilevel inverter (AMLI) topology is able to produce higher output voltage level without mod...

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Main Author:	Yatim, Mohd Hafizie
Format:	Thesis
Language:	English English English
Published:	2019
Subjects:	TK2000-2891 Dynamoelectric machinery and auxiliaries Including generators, motors, transformers
Online Access:	http://eprints.uthm.edu.my/566/1/24p%20MOHD%20HAFIZIE%20YATIM.pdf http://eprints.uthm.edu.my/566/2/MOHD%20HAFIZIE%20YATIM%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/566/3/MOHD%20HAFIZIE%20YATIM%20WATERMARK.pdf
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spelling	my-uthm-ep.5662021-08-05T03:30:10Z Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement 2019-01 Yatim, Mohd Hafizie TK2000-2891 Dynamoelectric machinery and auxiliaries. Including generators, motors, transformers This study presents a proposed symmetric and asymmetric multilevel inverter topologies using reduced number of switching devices (RNSD) structure for high power density achievement. Principally, asymmetric multilevel inverter (AMLI) topology is able to produce higher output voltage level without modification of the structure in order to reduce total harmonic distortion (THD). In contrast, the number of switching devices need to be increased in symmetric multilevel inverter (SMLI) topology and cascaded H-bridge (CHB) structure when higher output voltage level is considered. A 5-level RNSD structure is proposed as a circuit configuration for symmetric (5-level) and asymmetric (7-level and 9-level) multilevel inverters (MLIs). For switching strategies, modified pulse width modulation (MPWM), sinusoidal pulse width modulation (SPWM), modified pulse width modulation with reduced angle (MPWM-RA) and modified pulse width with low frequency triangular (MPWM-LFT) are selected to produce output voltage levels of the proposed structure. Theoretically, THD is reduced drastically when the number of output voltage level is increased and the MPWM-LFT is considered in this study. The results show that the voltage THD of the 7-level MLI is 21.6% with MPWM and 18.3% with SPWM. Meanwhile, with MPWM-RA, the voltage THD of the 7-level MLI is 12.2% while 11.6% with MPWM-LFT. In fact, with MPWM-RA and MPWM-LFT, the THDs are lower than with SPWM due to the optimum angle at the output voltage level considered. Therefore, the 7 and 9 levels AMLI shows the lowest THD, which are 11.6% and 9% respectively when MPWM-LFT and RNSD structures are considered. LC passive filter is considered in order to follow the IEEE Std 519-1992 using SPWM and shows that the THD of the 7-level AMLI is the lowest at 0.8% in simulation while 4.4% for experimental results. The comparison results based on the Pareto-Front method demonstrated that the proposed 7-level AMLI structure is able to achieve high efficiency at 98.52% and high power density of 4.46 kW/dm3 at 75 kHz as compared to the 7-level CHB structure even though the switching frequency changes from 2 kHz to 500 kHz. 2019-01 Thesis http://eprints.uthm.edu.my/566/ http://eprints.uthm.edu.my/566/1/24p%20MOHD%20HAFIZIE%20YATIM.pdf text en public http://eprints.uthm.edu.my/566/2/MOHD%20HAFIZIE%20YATIM%20COPYRIGHT%20DECLARATION.pdf text en staffonly http://eprints.uthm.edu.my/566/3/MOHD%20HAFIZIE%20YATIM%20WATERMARK.pdf text en validuser mphil masters Universiti Tun Hussein Onn Malaysia Fakulti Kejuruteraan Elektrik dan Elektronik
institution	Universiti Tun Hussein Onn Malaysia
collection	UTHM Institutional Repository
language	English English English
topic	TK2000-2891 Dynamoelectric machinery and auxiliaries Including generators, motors, transformers
spellingShingle	TK2000-2891 Dynamoelectric machinery and auxiliaries Including generators, motors, transformers Yatim, Mohd Hafizie Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
description	This study presents a proposed symmetric and asymmetric multilevel inverter topologies using reduced number of switching devices (RNSD) structure for high power density achievement. Principally, asymmetric multilevel inverter (AMLI) topology is able to produce higher output voltage level without modification of the structure in order to reduce total harmonic distortion (THD). In contrast, the number of switching devices need to be increased in symmetric multilevel inverter (SMLI) topology and cascaded H-bridge (CHB) structure when higher output voltage level is considered. A 5-level RNSD structure is proposed as a circuit configuration for symmetric (5-level) and asymmetric (7-level and 9-level) multilevel inverters (MLIs). For switching strategies, modified pulse width modulation (MPWM), sinusoidal pulse width modulation (SPWM), modified pulse width modulation with reduced angle (MPWM-RA) and modified pulse width with low frequency triangular (MPWM-LFT) are selected to produce output voltage levels of the proposed structure. Theoretically, THD is reduced drastically when the number of output voltage level is increased and the MPWM-LFT is considered in this study. The results show that the voltage THD of the 7-level MLI is 21.6% with MPWM and 18.3% with SPWM. Meanwhile, with MPWM-RA, the voltage THD of the 7-level MLI is 12.2% while 11.6% with MPWM-LFT. In fact, with MPWM-RA and MPWM-LFT, the THDs are lower than with SPWM due to the optimum angle at the output voltage level considered. Therefore, the 7 and 9 levels AMLI shows the lowest THD, which are 11.6% and 9% respectively when MPWM-LFT and RNSD structures are considered. LC passive filter is considered in order to follow the IEEE Std 519-1992 using SPWM and shows that the THD of the 7-level AMLI is the lowest at 0.8% in simulation while 4.4% for experimental results. The comparison results based on the Pareto-Front method demonstrated that the proposed 7-level AMLI structure is able to achieve high efficiency at 98.52% and high power density of 4.46 kW/dm3 at 75 kHz as compared to the 7-level CHB structure even though the switching frequency changes from 2 kHz to 500 kHz.
format	Thesis
qualification_name	Master of Philosophy (M.Phil.)
qualification_level	Master's degree
author	Yatim, Mohd Hafizie
author_facet	Yatim, Mohd Hafizie
author_sort	Yatim, Mohd Hafizie
title	Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
title_short	Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
title_full	Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
title_fullStr	Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
title_full_unstemmed	Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
title_sort	symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement
granting_institution	Universiti Tun Hussein Onn Malaysia
granting_department	Fakulti Kejuruteraan Elektrik dan Elektronik
publishDate	2019
url	http://eprints.uthm.edu.my/566/1/24p%20MOHD%20HAFIZIE%20YATIM.pdf http://eprints.uthm.edu.my/566/2/MOHD%20HAFIZIE%20YATIM%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/566/3/MOHD%20HAFIZIE%20YATIM%20WATERMARK.pdf
_version_	1747830640500277248

Symmetric and asymmetric multilevel inverter topologies with reduced number of switching devices structure for high power density achievement

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