A second fuel cell related patent was received by former visiting scientist Lizhi Zhu, now with Ballard Power Systems; Jih-Sheng Lai, associate professor of electrical and computer engineering, and Lee. Direct current (DC) generated by different power systems -- batteries and fuel cells, for instance -- must provide different voltage needs, such as 12 V lights, sensors, and controllers and 300 V traction inverters and motors. The patented "Accelerated commutation for passive clamp isolated boost converters" (6,452,815) is an efficient and cost effective bi-directional DC/DC converter that can effectively reduce switch voltage stress. Ballard Power Systems has a non-exclusive license because of their research sponsorship and funding the patent. They are actively pursuing potential product applications.
Graduate student Francisco Canales-Abarca, CPES technical coordinator Peter Barbosa, who was a Ph.D. student at the time of the research, and Lee received a patent for a "Zero voltage zero current three level DC-DC converter" (6,349,044). DC-DC power converters are required for high voltage, high power applications such as in telecommunications, battery chargers, and uninterruptible power supplies. The invention solves the problems of voltage loss, stress during switching, and cost.
Xunwei Zhou, a Ph.D. graduate in electrical engineering now at Linear Technology, and Lee received a patent for a "Current sensing and current sharing voltage regulator module (VRM)" (6,414,469). Today, every Intel proces
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Contact: Mike Martin
mike@vtip.org
540-951-9376
Virginia Tech
11-Apr-2003