Grid Connection Using a High-frequency Isolated DC/AC Module for Hybrid Power Systems

Abstract

To interface a hybrid power system with the utility line, multi-cell operation of a 1-ph converter module could be a feasible solution. Initially the operation, performance, and experimental verification of the 1-ph high-frequency isolated DC/AC resonant converter are presented. The high-frequency isolated DC/AC resonant module provides necessary voltage amplification and galvanic isolation for renewable energy generation. Full-range zero-voltage switching operation improves system overall efficiency and enables high-frequency operation with smaller reactive components. With this converter as a basic module, different schemes for high-power grid interface can be realized through proper control. It is also found that the dominant harmonics in both input DC current and the output line currents for single module operation are depressed if three identical 1-ph modules are connected in delta for a 3-ph grid connection.

Keywords:

• resonant converter
• grid-connection
• AC-to-DC conversion
• soft-switching
• high-frequency link

Additional information

Notes on contributors

Xiaodong Li

Xiaodong Li received the B.Eng. degree in electrical engineering from Shanghai Jiao Tong University, Shanghai, China, in 1994, the M.A.Sc. and Ph.D. degrees in electrical engineering from the University of Victoria, BC, Canada, in 2004 and 2009, respectively. From 1994 to 2002, he worked as an Electrical Engineer in HongWan Diesel Power Co., Zhuhai, China. He joined the Faculty of Information Technology, Macau University of Science and Technology, Macau SAR, China in 2009, where he is an Assistant Professor. Dr. Li is a senior member of IEEE. His research interest is the application of high-frequency power converters in renewable energy system.

Ashoka K. S. Bhat

Ashoka K. S. Bhat obtained the B.Sc. degree in physics and math from Mysore University, India, in 1972. He received the B.E. degree in electrical technology and electronics and the M.E. degree in electrical engineering, both with distinction from the Indian Institute of Science, Bangalore, in 1975 and 1977, respectively. He also received the M.A.Sc. and Ph.D. degrees in electrical engineering from the University of Toronto, Ontario, Canada, in 1982 and 1985, respectively. From 1977 to 1981, he worked as a scientist in the Power Electronics Group of the National Aeronautical Laboratory, Bangalore, India. Currently he is a Professor in the Department of Electrical and Computer Engineering, University of Victoria, B.C., Canada. Dr. Bhat is a Fellow of IEEE and the IETE (India), and a registered Professional Engineer in British Columbia, Canada. His main research interest is the high-frequency link power conversion, power converters for alternative energy sources.