Fault-Tolerant Modular Switched-Capacitor DC-DC Converter (MSCC) for Fuel Cells

Abstract

This study presents a new modular switched-capacitor DC-DC converter (MSCC) which is primarily designed with fault-tolerant capability to promote low-voltage applications such as fuel cells and photovoltaics. The converter can increase a low voltage level to a high voltage level by increasing the number of modules and/or the duty ratio. The proposed topology is modular and has high scalability for a high voltage gain. Another key advantage of the converter is its fault tolerance feature with a minimum change to the duty ratio. The proposed topology is first modeled analytically and then simulated in PSIM software with new control algorithms. The circuit architecture, operating principle, voltage/current stress and fault-tolerant operations are verified by using analytical and simulation methods based on a 200-V voltage supply. Moreover, experiments are also carried out on a low-voltage DC-DC prototype converter for validating the voltage ratio, efficiency and reliability. Test results have proved the effectiveness of the proposed topology under normal and fault conditions (open circuit faults of switches and capacitors). In addition to fuel cells, the developed converter can also be applied to photovoltaics and other low-voltage DC power systems which demand high efficiency, voltage output and high reliability.

Keywords:

• fault tolerance
• fuel cells
• modular switched-capacitor DC-DC converter (MSCC)
• photovoltaics
• reliability

Additional information

Funding

This work was supported by the Science and Technology Key Special Project of Anhui Province under No. 2022h11020023 and National Nature Science Foundation Council, China (NSFC 51867007).

Notes on contributors

Xiangping Chen

Xiangping Chen received the Ph.D. degree in electronic and electrical engineering from Newcastle University, Newcastle upon Tyne, U.K., in 2013. She is currently with Guizhou University, China, as a Professor. Her expertise also lies in optimal operation in multivector energy systems and their applications in smart grids. Her research interests include renewable energy, energy management, and energy storage technologies.

Zhengzhao He

Zhengzhao He received the MSc and PhD degree in electrical and electronic engineering from Newcastle University and Aston University, UK, in 2014 and 2019, respectively. He is currently with Geely Cars, Cixi, P. R. China. His work is focused on high-performance power converters for EVs.

Dong Wang

Dong Wang received the BEng and MSc degree in electrical and electronic engineering from East China Jiaotong University and Beijing Jiaotong University, P. R. China, in 2004 and 2007 respectively. He is currently a Director for Goldwind Science & Creation Windpower Equipment Co. Ltd. Beijing, China. His interest lies in the reliability of large wind turbine generators.

Wenping Cao

Dong Wang received the BEng and MSc degree in electrical and electronic engineering from East China Jiaotong University and Beijing Jiaotong University, P. R. China, in 2004 and 2007 respectively. He is currently a Director for Goldwind Science & Creation Windpower Equipment Co. Ltd. Beijing, China. His interest lies in the reliability of large wind turbine generators.

Wenping Cao received the B.Eng. in electrical engineering from Beijing Jiaotong University, Beijing, China, in 1991, and Ph.D. degree in electrical machines and drives from the University of Nottingham, Nottingham, in 2004. He is Chair Professor of Electrical Engineering with Anhui University, Hefei City, China. He received a “Royal Society Wolfson Research Merit Award” in 2016, the “Dragon’s Den Competition Award” from Queen’s University Belfast in 2014, the “Innovator of the Year Award” from Newcastle University, UK, in 2013. He is IET Fellow, Royal Society Wolfson Fellow and Marie Curie Fellow. He has been Associate Editor for IEEE Transactions on Power Electronics, IEEE Transactions on Industry Application, IET Power Electronics, and editor for several international journals. His research interests include fault analysis and condition monitoring of electrical machines and power electronics.