Cascaded Multilevel Inverters Using Proposed Series Sub-multilevel Basic Blocks with Reduced Switching Devices

Abstract

In this paper, a novel configuration of the cascaded multilevel inverters using series connection of new sub-multilevel basic blocks is presented. The basic structure of the proposed sub-multilevel inverter is made of three isolated batteries and eight unidirectional power switches. Hereby, by changing the polarity of one of such batteries and two power switches, two different modules of sub-multilevel inverters can be extracted that each of them is able to be incorporated into two different cascaded structures as the series basic blocks. Contemporary, to determine the suitable magnitudes of the integrated batteries, two different algorithms for each topology along with their relevant mathematical analysis have been also given. In this study, a complete comparison between the proposed topologies and several recently presented structures has been conducted. The compiled comparisons can prove the fact that both the proposed cascaded inverters are capable of generating a higher number of output voltage levels with less number of switching counts. Other advantages of these structures are reduction of voltage sources numbers, DC sources variety, value of total blocking voltage, and also conducting losses. In order to demonstrate the correct operation of the proposed structures and presented algorithms, some experimental results will be also shown.

Keywords::

• cascaded multilevel inverter
• DC voltage sources magnitudes
• lower value of blocked voltage
• sub-multilevel inverters

Additional information

Notes on contributors

Elyas Zamiri

Elyas Zamiri received the B.Sc. degree in electrical engineering from the University of Guilan, Rasht, Iran, in 2012, and the M.Sc. degree from the University of Tabriz, Tabriz, Iran, in 2014. His research areas include investigation on new topologies of multilevel voltage source inverters, switched-capacitor DC–DC converters, photovoltaic grid-tied ac module, and renewable energy systems.

Majid Moradzadeh

Majid Moradzadeh was born in Ardabil, Iran, in 1989. He received the B.Sc. degree in electrical power engineering from the Mashhad Institute of Technology (MIT), Mashhad, Iran, in 2011, and the M.Sc. degree from the University of Tabriz, Tabriz, Iran, in 2014. His current research interests include microgrids, design, and control of DC–DC converters and multilevel inverters, and their applications in renewable energy systems.

Reza Barzegarkhoo

Reza Barzegarkhoo received the B.S. degree in electrical power engineering from the University of Guilan, Rasht, Iran, in 2010, and the M.S. degree from the Sahand University of Technology (SUT), Tabriz, Iran, in 2012. His current research interests include the design and control of power electronic converters, multilevel voltage source inverters, charge balancing control, switched-capacitor converters, photovoltaic grid-tied AC module, and distributed generation systems.

Sajad Hamkari

Sajjad Hamkari was born in Khoy, Iran, in 1990. He received the B.Sc. degree in electrical engineering from the University of Shahid Madani Azarbaijan, Tabriz, Iran, in 2012, and the M.Sc. degree from the Tabriz University, Tabriz, Iran, in 2014. His current research interests include power electronics, charge controllers, power converters, multilevel inverters, and renewable energy systems.

Mehran Sabahi

Mehran Sabahi was born in Tabriz, Iran, in 1968. He received the B.S. degree in electronic engineering from the University of Tabriz, the M.S. degree in electrical engineering from Tehran University, Tehran, Iran, and the Ph.D. degree in electrical engineering from the University of Tabriz, in 1991, 1994, and 2009, respectively. Since 2009, he joined the Faculty of Electrical and Computer Engineering, University of Tabriz, where he was an Assistant Professor from 2009 to 2013 and where he has been an Associate Professor since 2014. His current research interests include power electronic converters and renewable energy systems.