A Switched-Capacitor Multilevel Inverter with Reduced Power Components in Current Loops for Renewable Energy Generation

Abstract

A switched-capacitor multilevel inverter (SCMLI) is proposed in this article for the DC-AC conversion in the renewable energy generation (REG) system. The proposed topology reserves the advantages of common SCMLIs, such as the boost ability, the self-voltage balancing of capacitors, and the inductive-load. Thus, the conventional two-stage DC-AC structure in the REG system can be realized through a single stage with only one controller, thus decreasing the complexity and increasing the efficiency. The major advantage of the proposed SCMLI over the existing ones is that reduced components are contained in current loops, which can further increase the conversion efficiency. The circuit topology, operating mechanism, and parameter analysis of the proposed SCMLI are presented. Qualitative and quantitative efficiency comparisons with typical SCMLIs are conducted. A nine-level simulation model and the corresponding experimental prototype are implemented for performance evaluations. Finally, the feasibility and superiority are verified by a 230-W experimental prototype.

Keywords:

• renewable energy generation
• switched-capacitor multilevel inverter (SCMLI)
• higher conversion efficiency
• boost ability

Additional information

Funding

This work was supported in part by the National Natural Science Foundation of China (Grants 61573155 and 51877085), in part by Guangdong Natural Science Foundation (Nos. 2016A03031358 and 2018A030313066), in part by Guangdong Science and Technology Planning Project (Nos. 2016A010102007 and 2016B090918028), and in part by central university of SCUT (No. 2018ZD50).

Notes on contributors

Junfeng Liu

Junfeng Liu received the M.S. degree in control engineering from the South China University of Technology, Guangzhou, China, in 2005, and the Ph.D. degree in electrical engineering from the Hong Kong Polytechnic University, Kowloon, Hong Kong, in 2013. From 2005 to 2008, he was a Development Engineer in Guangdong Nortel Network, Guangzhou, China. In 2014, he joined the South China University of Technology, Guangzhou, where he was an Associate Professor at the School of Automation Science and Engineering. His research interests include power electronics applications, nonlinear control, high frequency power distribution system, and motion control system.

Jialei Wu

Jialei Wu was born in Jiangsu, China, in 1992. He received his B.S. degree in Electrical Engineering and Automation from the China University of Mining and Technology, Xuzhou, China, in 2015. He is currently working toward his M.S. degree in Power Electronics and Drives at South China University of Technology, Guangzhou, China. His research interests include high frequency power distribution system and renewable energy generation.

Xiangkai Zhu

Xiangkai Zhu was born in Zhumadian, China, in 1995. He received his B.S. degree from the Henan University, Kaifeng, China, in 2017. He is currently working toward his M.S. degree in Automation Science and Engineering at South China University of Technology, Guangzhou, China. His research interests include power electronics applications and high frequency power distribution system.

Jun Zeng

Jun Zeng received the Ph.D. degree in control theory and control engineering from the South China University of Technology, Guangzhou, China, in 2007. She is currently a Professor in the Electric Power College of the South China University of Technology, Guangzhou. Her current research interests include power electronics applications, energy management and intelligence control in distributed generation, and integration of renewable energy to smart grid.