Journal article
Analysis and Design of a Bidirectional Isolated DC-DC Converter for Fuel Cell and Super-Capacitor Hybrid System
Electrical power system in future uninterruptible power supply (UPS) or electrical vehicle (EV) may employ hybrid energy sources, such as fuel cells and super-capacitors. It will be necessary to efficiently draw the energy from these two sources as well as recharge the energy storage elements by the DC bus.
In this paper, a bidirectional isolated DC-DC converter controlled by phase-shift and duty cycle for the fuel cell hybrid energy system is analyzed and designed. The proposed topology minimizes the number of switches and their associated gate driver components by using two high frequency transformers which combine a half-bridge circuit and a full-bridge circuit together on the primary side.
The voltage doubler circuit is employed on the secondary side. The current-fed input can limit the input current ripple that is favorable for fuel cells. The parasitic capacitance of the switches is used for zero voltage switching (ZVS). Moreover, a phase-shift and duty cycle modulation method is utilized to control the bidirectional power flow flexibly and it also makes the converter operate under a quasi-optimal condition over a wide input voltage range.
This paper describes the operation principle of the proposed converter, the ZVS conditions and the quasi-optimal design in depth. The design guidelines and considerations about the transformers and other key components are given. Finally, a 1- kW 30~50-V-input 400-V-output laboratory prototype operating at 100 kHz switching frequency is built and tested to verify the effectiveness of the presented converter.
Language: | English |
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Publisher: | IEEE |
Year: | 2012 |
Pages: | 848-859 |
ISSN: | 19410107 and 08858993 |
Types: | Journal article |
DOI: | 10.1109/TPEL.2011.2159515 |
ORCIDs: | Zhang, Zhe , Ouyang, Ziwei and Andersen, Michael A. E. |
Bidirectional dc–dc converter Capacitors DC-DC power convertors Fuel cells Load flow Uninterruptible power systems Voltage control Windings ZVS Zero voltage switching bidirectional isolated DC-DC converter design bidirectional power flow control bridge circuits current-fed dc bus driver circuits duty-cycle modulation electrical power systems electrical vehicles energy storage elements frequency 100 kHz fuel cell (FC) fuel cell-supercapacitor hybrid system fuel cells fuel-cell hybrid energy system full-bridge circuit gate driver components half-bridge circuit high-frequency transformers hybrid energy sources hybrid power systems input current ripple load flow control parasitic capacitance phase shift phase-shift modulation power 1 kW quasioptimal design supercapacitor (SC) supercapacitors switching convertors uninterruptible power supplies voltage 400 V voltage doubler circuit zero voltage switching