Converter Systems for Fuel Cells in the Medium Power Range-A Comparative Study

• Published in: IEEE transactions on industrial electronics (1982) Vol. 57; no. 6; pp. 2024 - 2032
• Main Authors: Mohr, Malte, Franke, Wulf Toke, Wittig, Bjoern, Fuchs, Friedrich Wilhelm
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2010; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Computing time; Converters; Current-source inverter (CSI); dc-dc power conversion; DC-DC power converters; Direct current; Electric power generation; Feeds; Fuel cells; Insulated gate bipolar transistors; Inverters; Laboratories; MOSFETs; Power rating; Power transformer insulation; Semiconductors; Topology; Voltage; voltage-source inverter (VSI); z-source inverter
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2010.2044730

Inverter systems that feed electrical power from fuel cells into the grid must convert the direct current of the fuel cell into the alternating current of the grid. In addition, these inverters have to adapt the different voltages of the fuel-cell system and the grid to each other. In this paper, different topologies of appropriate inverter systems in the medium power range of 20 kW and higher are presented briefly. The inverter operating behavior, power rating, and efficiency are compared. The power rating and efficiency are compared using an analytical calculation of the semiconductor losses. The study includes transformerless inverters as well as two-stage inverter systems with high-frequency transformers (dc/dc converter combined with an inverter). This paper compares converter systems using insulated-gate bipolar transistors (IGBTs), e.g., a boost converter in series with a voltage-source inverter (VSI), current-source inverter, and z-source inverter or converter systems using superjunction MOSFETs, such as voltage- and current-fed full-bridge converters or a boost converter with an autotransformer. The MOSFET-based dc/dc converters must be connected in series to a VSI with IGBTs to feed into the three-phase grid. The presented converters were tested in the laboratory. Some characteristics of their laboratory performance are shown.