Abstract: This invention relates to the field of thermophotovoltaic (TPV) direct energy conversion. In particular, TPV systems use filters to minimize parasitic absorption of below bandgap energy. This invention constitutes a novel combination of front surface filters to increase TPV conversion efficiency by reflecting useless below bandgap energy while transmitting a very high percentage of the useful above bandgap energy. In particular, a frequency selective surface is used in combination with an interference filter. The frequency selective surface provides high transmission of above bandgap energy and high reflection of long wavelength below bandgap energy. The interference filter maintains high transmission of above bandgap energy and provides high reflection of short wavelength below bandgap energy and a sharp transition from high transmission to high reflection.
Type:
Grant
Filed:
October 12, 2006
Date of Patent:
September 7, 2010
Assignee:
The United States of America as represented by the United States Department of Energy
Inventors:
Randolph J. Dziendziel, Paul F. Baldasaro, David M. DePoy
Abstract: A process has been developed for fabricating composite structures using either reaction forming or polymer infiltration and pyrolysis techniques to densify the composite matrix. The matrix and reinforcement materials of choice can include, but are not limited to, silicon carbide (SiC) and zirconium carbide (ZrC). The novel process can be used to fabricate complex, net-shape or near-net shape, high-quality ceramic composites with a crack-free matrix.
Type:
Grant
Filed:
August 17, 2006
Date of Patent:
December 8, 2009
Assignee:
The United States of America as represented by the United States Department of Energy
Abstract: A continuous method of producing propylenecarbonate includes carboxylation of propylene oxide with carbon dioxide in presence of phthalocyanine catalyst on an inert carrier, using as the phthalocyanine catalyst at least one catalyst selected from the group consisting of not-substituted, methyl, ethyl, butyl, and tret butyl-substituted phthalocyanines of metals, including those containing counterions, and using as the carrier a hydrophobic carrier.
Type:
Grant
Filed:
September 21, 2006
Date of Patent:
September 8, 2009
Assignee:
U.S. Department of Energy
Inventors:
Vladimir Vasilievich Afanasiev, Nikolai Serafimovich Zefirov, Dmitry Yurievich Zalepugin, Victor Stanislavovich Polyakov, Nataliya Alexandrovna Tilkunova, Larisa Godvigovna Tomilova
Abstract: A gate drive for an insulated gate bipolar transistor (IGBT) includes a control and protection module coupled to a collector terminal of the IGBT, an optical communications module coupled to the control and protection module, a power supply module coupled to the control and protection module and an output power stage module with inputs coupled to the power supply module and the control and protection module, and outputs coupled to a gate terminal and an emitter terminal of the IGBT. The optical communications module is configured to send control signals to the control and protection module. The power supply module is configured to distribute inputted power to the control and protection module. The control and protection module outputs on/off, soft turn-off and/or soft turn-on signals to the output power stage module, which, in turn, supplies a current based on the signal(s) from the control and protection module for charging or discharging an input capacitance of the IGBT.
Type:
Grant
Filed:
February 27, 2008
Date of Patent:
August 4, 2009
Assignee:
The United States of America as represented by the United States Department of Energy
Inventors:
James Evans Short, Shawn Michael West, Robert J. Fabean
Abstract: An adaptive protection algorithm and system for protecting electrical distribution systems traces the flow of power through a distribution system, assigns a value (or rank) to each circuit breaker in the system and then determines the appropriate trip set points based on the assigned rank.
Type:
Grant
Filed:
March 31, 2005
Date of Patent:
April 28, 2009
Assignee:
The United States of America as represented by the United States Department of Energy
Inventors:
Paul Hedrick, Helen L. Toms, Roger M. Miller