This book focuses on a safety issue in terms of leakage current, builds a common-mode voltage analysis model for TLIs at switching frequency scale and develops a new modulation theory referred as "Constant Common-Mode Voltage Modulation" to eliminate the leakage current of TLIs. Transformerless Grid-Connected Inverter (TLI) is a circuit interface between photovoltaic arrays and the utility, which features high conversion efficiency, low cost, low volume and weight. The detailed theoretical analysis with design examples and experimental validations are presented from full-bridge type, half-bridge type and combined topologies. This book is essential and valuable reference for graduate students and academics majored in power electronics; engineers engaged in developing distributed grid-connected inverters; senior undergraduate students majored in electrical engineering and automation engineering.

Huafeng (Henry) Xiao received the B.S., M.S. and Ph.D. degrees in electrical engineering from Nanjing University of Aeronautics and Astronautics (NUAA), Nanjing, China, in 2004, 2007, and 2010, respectively. From 2015 to 2017, he was a postdoctoral fellow at Laboratory of Electric Drives and Application Research (LEDER), Ryerson University, Toronto, Canada, and at Electric Energy Systems Laboratory (EESL), McGill University, Montreal, Canada, respectively. He is currently a Professor at School of Electrical Engineering, Southeast University, China. He has authored or coauthored over 70 journal and conference papers, and held 36 China Patents. His main research interests include Topology, control, and protection techniques of renewable energy generation systems, Multi-terminal MMC-HVDC, WBG devices applications. Dr. Xiao received a gold medal from 47th International Exhibition of Inventions Geneva. Currently, he serves as an Associate Editor for IEEE Transactions on Industrial Electronics, and IET Power Electronics. Xiaobiao Wang received the B.S. and M.S. degrees in electrical engineering from AnHui Agricultural University and Northeastern University, China in 2015 and 2018, respectively. He is currently working toward the Ph.D. degree in electrical engineering in Southeast University, China. His research interests include renewable energy grid-connected multilevel inverter topologies and modulation strategies.