Renewable energy has nowadays become important in electrical power applications. Power converters play an important role in integrating these distributed energy sources. However, due to their intermittence characteristics, e.g., the output power provided by the PV and wind turbine is not stable, either an energy storage system will be used or microgrid is formed between the main grid and the sources. To integrate these renewable energy sources and manage the power flow, a multiport converter is preferred because it is highly beneficial and cost-efficiently than the traditional solution that using multiple individual power converter for each source. This thesis proposed a novel four-port bidirectional DC-DC converter with a battery storage system, which uses phase-shift control of two active bridges connected through two transformers. Compared with the traditional multiport converters, the proposed four-port converter uses the least number of power switches and zero-voltage switching (ZVS) for all the switches can be realized. The design and effectiveness of controllers are validated by experimental results. The converter can work in different scenarios regardless of the availability of renewable energy and the state-of-charge of the battery. In addition, maximum power point tracking for renewable energy sources can be achieved for each renewable energy source while managing the power flow of the battery.


Jianwu Zeng

Committee Member

Vincent Winstead

Committee Member

Qiang Ye

Date of Degree




Document Type



Master of Science (MS)


Electrical and Computer Engineering and Technology


Science, Engineering and Technology

Creative Commons License

Creative Commons Attribution-NonCommercial 4.0 International License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License



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