**Contents**



### **About the Special Issue Editors**

**Jens Bo Holm-Nielsen** received his M.Sc. degree in Agricultural Systems, Crops & Soil Science, from KVL, Royal Veterinary & Agricultural University, Copenhagen, Denmark, in 1980 and Ph.D. degree in Process Analytical Technologies for Biogas Systems, Aalborg University, Esbjerg, Denmark, in 2008. He is currently with the Department of Energy Technology, Aalborg University, Esbjerg, Denmark, and Head of the Esbjerg Energy Section. He is Head of the research group at the Center for Bioenergy and Green Engineering, established in 2009. He has vast experience in the field of biorefinery concepts and biogas production–anaerobic digestion. He has implemented bioenergy system projects in provinces of Denmark and in other European states. He has been the Technical Advisor for many industries in this field. He has executed many large-scale European Union and United Nation projects in research aspects of bioenergy, biorefinery processes, and the full chain of biogas and green engineering. He has authored more than 300 scientific papers. His current research interests include renewable energy, sustainability, and green jobs for all. Dr. Holm-Nielsen was a member on invitation with various capacities in the committees of over 500 various international conferences and organizer of international conferences, workshops, and training programs in Europe, Central Asia, and China.

**P. Sanjeevikumar** (Senior Member, IEEE) received the Bachelor's degree in Electrical Engineering from the University of Madras, Chennai, India, in 2002; the Master's Degree (Hons.) in Electrical Engineering from Pondicherry University, Puducherry, India, in 2006; and the Ph.D. degree in Electrical Engineering from the University of Bologna, Bologna, Italy, in 2012. He was an Associate Professor with VIT University from 2012 to 2013. In 2013, he joined the National Institute of Technology, India, as a Faculty Member. In 2014, he was invited as a Visiting Researcher at the Department of Electrical Engineering, Qatar University, Doha, Qatar, funded by the Qatar National Research Foundation (Government of Qatar). He continued his research activities with Dublin Institute of Technology, Dublin, Ireland, in 2014. He was an Associate Professor with the Department of Electrical and Electronics Engineering, University of Johannesburg, Johannesburg, South Africa, from 2016 to 2018. Since 2018, he has been a Faculty Member with the Department of Energy Technology, Aalborg University, Esbjerg, Denmark. He has authored more than 300 scientific papers. Dr. Padmanaban received awards for Best Paper or Most Excellent Research Paper from IET-SEISCON 2013, IET-CEAT 2016, IEEE-EECSI 2019, and IEEE-CENCON 2019, along with five best paper awards from ETAEER 2016. He also sponsored Lecture Notes in Electrical Engineering, a Springer book. He is a Fellow of the Institution of Engineers, India; the Institution of Electronics and Telecommunication Engineers, India; and the Institution of Engineering and Technology, U.K. He is an Editor/Associate Editor/Editorial Board Member for refereed journals, in particular for IEEE Systems Journal, IEEE Transactions on Industry Applications, IEEE Access, IET Power Electronics, and Wiley's International Transactions on Electrical Energy Systems. He is the Subject Editor for IET Renewable Power Generation; IET Generation, Transmission & Distribution; and FACTS journal (Canada).

## **Preface to "Power Electronic Converter Configuration and Control for DC Microgrid Systems"**

Writing a preface is always a challenging task, but I always enjoy recommending works in my field of power electronics and renewable energy technologies—an application which benefits society and solves power demand crises. It was therefore my pleasure to read and recommend this book, *Power Electronic Converter Configuration and Control for DC Microgrid*, authored/edited by my colleagues Jens Bo Holm-Nielsen and Sanjeevikumar Padmanaban from Aalborg University, Esbjerg, Denmark, as it has shown exciting and cutting-edge research findings in power electronics for microgrids. Readers can find four different sections in the book: conceptual review detailing the state of the art, research investigation outcomes, new configuration technologies, and real-time hardware-in-loop testing for validation. This approach makes this book unique and user-friendly in reading and understanding the complexity of the topics discussed.

Microgrids and renewables are continuously gaining attention as crucial empowering technologies with smart control approaches to enhance system reliability and efficiency. These challenges are solvable through modern power electronics converters, with higher flexibility, adjustable electronic loads, and energy storage systems (batteries). From my reading, the topics which I anticipate will draw strong reader attention are the new configuration of the DC-to-DC converter, multiport converters, multilevel inverters, load sharing concept, wireless charging network, battery management schemes, large-scale renewable integration challenges and issues, selection of permanent magnet machines for wind energy technology, and hardware-in-loop test findings towards microgrid system and electric vehicle charging through renewable energy systems.

Finally, I congratulate and thank the editors, authors, *Energies* journal, MDPI publishers, reviewers, and press production team. This book is a result of their support and effort on all levels.

I hope the readers will enjoy reading this book and will be able to apply the research findings herein for further future enhancement in technology and skills!

### **Prof. Frede Blaabjerg**

*Fellow IEEE Villum Investigator Professor Aalborg University, Denmark.*

*Review*
