| DC Power Converter for 200°C Containing SiC Transistors |
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| Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio | |
| Jan 31 2008 | |
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Advertisement: Because of the manner in which the magnetic flux in the transformer core is reset in this switching cycle, the duty cycle is limited, in principle, to no more than 1⁄2. In the design of this power converter, a practical duty-cycle value of 0.45 is used. One key advantage of the design is that the transformer leakage-inductance energy is fed back to the input capacitor via RD1 and RD2. Another advantage is that the maximum voltage stress on S1, S2, RD1, and RD2 is limited to the input voltage, so that primary side snubber circuits are not needed. Yet another advantage is that voltage shootthrough is absent because S1 and S2 are turned on and off simultaneously. In tests, this power converter was found to be capable of operating, as intended, at temperatures up to 200°C. In a contemplated update of the design, the input capacitor would be replaced by one rated for higher temperature in the hope of enabling operation up to at least 250°C. Also under consideration are implementation of a higherpower version using a full bridge topology and the replacement of the SiC bipolar junction transistors with SiC junction fieldeffect transistors or metal oxide/semiconductor field-effect transistors. This work was done by James D. Scofield and Brett Jordan of the Air Force Research Laboratory, Biswajit Ray of Bloomsburg University of Pennsylvania, and Hiroyuki Kosai of UES, Inc. Prev: A Comparison of SiC-Based Devices for Use as Power Switches Next: Protection Schemes for Advanced Shipboard Electrical Systems |
