New solid-state power switch safeguards electric service

"The nation's electric grid is operating so close to capacity that many of today's electric load demands for fast and dynamic voltage support cannot be provided fast enough," says Alex Huang, professor of electrical and computer engineering at Virginia Tech.

To solve the problem, Virginia Tech researchers have developed a high-power semiconductor switch. The invention has earned a 2003 R & D 100 Award from R & D Magazine. The magazine will announce the "100 most technologically significant products introduced into the marketplace over the past year" in its September issue.

Huang, a researcher with the Center for Power Engineering Systems (http://www.cpes.vt.edu) is the principal developer of the switch, called an Emitter Turn-off (ETO) Thyristor.

"The ETO is a solid-state switch that is suitable for use in high-frequency power converters that can provide fast and dynamic voltage support to our nation's congested power grid," says Huang. It offers fast switching speed, rugged turn-off capacity, and voltage control.

The ETO is a three terminal integrated power switch. An optical pulse is applied to turn on current flow with very little resistance. When it is closed, it can conduct 10,000 amps of current. "This is not your typical switch," says Huang.

For continuous operation, the range is 1,500 amps to keep the temperature below 125 degrees C. When the optical pulse is removed, and the ETO switch opens, it can block voltage as high as 6,000 V. The ETO changes from on to off and off to on in less than 5 microseconds. During switching, the ETO withstands high voltage and high current simultaneously. It is a voltage turnoff device with real time current sensing capability that can be used for control and protection.

"This switch allows us to advance very high power converters from a line speed of 60 Hz to 1 to 3 kHz (kilo hertz) switching at the same power level. This speed allows you to chop the voltage into whatever shape you need," says Huang.

Present technology is the Gate Turn-Off (GTO) Thyristor, the main power switch in use. The GTO is reliable and inexpensive, but requires a "snubber" capacitor to protect it in the turnoff process. The snubber uses significant power itself, increases the size of the switch and the complexity of energy recovery circuits. In addition to being a complicated gate design, it slows the on-off process.

"The significance is the ETO allows you to reduce energy storage elements and size (conductors, capacitors), which reduces the size, the weight, and the cost of the power converter," says Huang.

An insulated gate bipolar transistor (IGBT), which doesn't require a snubber, was developed in the early 1990s. It offered improved control and reliability, but it is LESS useful in high power applications. The ETO is a hybrid of the GTO and the IGBT - "so is proven reliable," says Huang.

The U.S. Department of Energy's Energy Storage Systems Program, managed by Sandia National Laboratory, first funded Huang's research on what are known as "flexible AC transmission systems (FACTS). Because the ETO has the highest power handling capacity among all solid-state switches, it was deemed useful for such high-power application as FACTS devices and the U.S. Navy's new electromagnetic aircraft launch system. The Tennessee Valley Authority is currently funding research by Virginia Tech to use the ETO in a high-power converter for dynamic voltage support in transmission and distribution grids.

Material limitations and the high cost of power electronic devices have restricted the wide spread use of power electronics in utility transmission and distribution grids. The ETO is a key enabling technology for lower cost power electronic systems. The timing is excellent. "Deregulation has created new demands on the transmission infrastructure, straining reserves. Power electronic systems, such as the ETO, can improve quality and capacity of the transmission grid by 25 to 60 percent," says Jing Leng of Solitronics, a spin-off company started in Blacksburg, Va., to commercialize the ETO.

The increasing frequency of electricity outages and outage duration are due primarily to lack of quick voltage support, leading to voltage collapse in many regions of the country and poor quality of power (flicker, for instance), she wrote in the R & D entry. One result has been lost opportunities in manufacturing and other businesses dependent on steady or high capacity power systems.

"We are losing hundreds of millions of dollars due to the loss of electrical power," says Huang. "Our ability to get electrical power to where it is needed, when it is needed, is impeded by technology that is too slow," Leng wrote.

But with the ETO, you can respond to demand faster, says Huang. "When to stop and when to conduct electricity can be determined by a computer. Several ETO switches will be in systems connected to an electric grid. When you can switch faster, the equipment can respond faster.

"So, it's low cost, high performance, high frequency, high power," says Huang. "It will withstand 16 megawatts of instantaneous power. Like turning on 100 stoves instantly through a unit about the size of a graham cracker. And you can stop them all at once too."

Several patents are pending. American Competitiveness Institute helped develop a manufacturing process for the ETO. Solitronics licensed the product from Virginia Tech Intellectual Properties, Inc. The R & D 100 awards will be presented at a banquet in Chicago on Oct. 16.

For more information, contact: Alex Q. Huang, (540) 231-8057 or huang@vt.edu; Jing Leng, Solitronics, (540) 961-6805; Virginia Tech Intellectual Properties, Inc., www.vtip.org. Learn more about power electronics research at Virginia Tech at http://www.research.vt.edu/resmag/2002winter/power.html.

Tech team wins "Editor's Choice Award" at International Contemporary Furniture Fair

Associate Dean and Director of Industrial Design Robert Dunay answered a Request for Proposal advertised in Interior Design Magazine, and the work was selected to receive a complimentary exhibit space. Each year, the ICFF holds a juried competition to select the top design schools to fill these spots which are among the most coveted at the fair because the students are invited to present their works-in-progress alongside the finished products of the international design community's leading designers and manufacturers. During the event, a panel of editors from leading design journals judged all the exhibits in 16 categories. Winners were named at an awards ceremony at the event. The Virginia Tech exhibit was chosen winner of the "design school" category, competing against the Art Center College of Design, Pasadena, California; Parsons School of Design, New School University, New York, New York; and the Pratt Institute, Brooklyn, New York. This is the first time Industrial Design has answered the RFP, the first time to have been selected to exhibit, and as rookies came away the top winner in their category.

The 10 x 20 ft. exhibit represented a portion of the solar house (designed last year to compete in the National Solar Decathlon held in Washington, D.C.) emphasizing the structure's materials, and showcasing furniture made by industrial design students. "We already had the raw material, so when I saw the RFP, it seemed to fit in terms of the industrial design program and the university and what it could bring in terms of national recognition. I also saw it as an educational opportunity -- for seven students to participate in something like this is a chance they'll rarely get in their academic studies," says Dunay.

When the students weren't manning the exhibit, they had the chance to walk around and visit the exhibits from 400 designers, manufacturers, and representative firms displaying choice examples of contemporary furniture, seating, lighting, carpet and flooring, wall coverings, textiles, materials, accessories, kitchen and bath products, and outdoor furniture for residential and commercial interiors. "It is an outreach project, it's a spin off of a research project, and it provides a unique educational experience outside the classroom. It simultaneously fulfills the three missions of the university," says Dunay.

The efficient design of the exhibit utilized the actual packaging crate used to transport it to New York. The structure was designed as a spatial expression of the solar house. One wall of the crate became the floor, and the other panel served as a large exhibit wall. A special structure was integrated to allow forklift transport. This frame also contained electrical distribution and held computers and a plasma screen that continuously showed the 7-minute Solar Decathlon video developed by VT's Visual and Broadcast Communications.

Student team members who traveled to New York included Aaron Emmons (lead), Yousef Nawas, Ross Marks, Stefani Bachetti, Junko Hosokawa, Tor Stevertson, and Chollaporn Ounkomol. Also working on the exhibit were Kelly Blanchard and Joe McCoy. When asked what stood out the most about the experience, Nawas said seeing all the design at the Javits Center was exciting. "When you go there, you get to see different trends, different schools of thought, different ideas, and things you've never encountered before."

When comparing the Virginia Tech exhibit to the other participating schools, Nawas said ours was distinctively different. "It was not superficially polished like many of the exhibits at the exposition, but you could see there were tons of ideas in one element," Nawas gives the credit to Emmons, who designed the display, and says "we didn't go into this with the mindset of winning a prize or seeking fame - we were there with our best to promote our ideas about design and sustainability. Winning first in the design school category was merely the result of doing what we love to do--design--and people could tell by exploring our pavilion." As winners, the team will automatically be invited to exhibit at next year's fair.

For more information on the students' exhibit, go to http://www.caus.vt.edu/CAUS/CAUSNews/more/icff/

Veterinary college researcher awarded prestigious NSF grant

Dr. Taranjit Kaur has received the prestigious NSF funding to support a five-year program entitled "Bridging the Gaps Using Bush-to-Base-Bio-Informatics, Geographic Information Systems (GIS) and a Program Called "READ-IT."

"This is all about integrating research and education," said Kaur, who also serves as Virginia Tech's director of laboratory animal resources. She plans to create an "electronic infrastructure" that will take a multidisciplinary approach to developing improved wildlife management strategies in the east African nation.

Kaur, who has traveled to Africa several times, conceived the project around a proprietary program she has developed called "READ-IT," an acronym which stands for Research, Education, and Dissemination via Information Technology. It represents a multidisciplinary career development strategy that seeks to bridge the gaps between discovery, learning and the diffusion of information in the biological sciences.

"Everything I do brings together humans, animals and the environment, and the dynamic interaction between them," said Kaur. The goal of this project transcends the immediate benefit of using technology and training programs to improve conservation management strategies for chimpanzee populations in the jungles of a nation home to the famed Mount Kilimanjaro, Kaur explains.

To accomplish this greater goal, she plans to focus on the immediate task of helping the Tanzanian National Park Authority (TANAPA) develop science-based management strategies that will protect the free-ranging chimpanzee population from tourism-related problems like disease transmission, habitat destruction, and competition for resources. Because of genetic similarities between chimps and people, both are highly susceptible to influenza, tuberculosis and other infectious diseases.

That information will enable those officials to determine a more accurate understanding of the area's capacity for tourism, as well as support the development of more effective management and training programs for professionals and tourists.

A key part of Kaur's program is designed to develop "interesting and compelling content for integrated research and educational opportunities for undergraduate, graduate and professional students at Virginia Tech." Some of those will be involved with the "Bush to Base Bio-Informatics" and the "Geographic Information Systems" components of the program, she said.

Field researchers will gather physiological data on the chimps, and code and process the data using handheld modules with global positioning system capability, Kaur said. The modules will interface with a Virginia Tech-based web-enabled server designed to share information with authorized users.

"My theory is that students are a tremendous resource and that we don't utilize them enough," said Kaur, who views students as key players in a "cross-pollination" component of the program. Students participating in the program will gain interdisciplinary research and educational experiences within a global context by designing communication systems and sharing information with other students, tourists, wildlife personnel, and local communities, Kaur said.

Another goal of the program is to use U.S. technological leadership in a way that supports sustainable global development, promotes conservation, and ultimately leads to a higher quality of life for all in the 21st century, she said.

She seeks to use the READ-IT concept to develop "an integrated electronic infrastructure that will act as a catalyst for the transmission of information across many boundaries, perpetuating a cycle of information transfer and serving as a blueprint for bridging the gaps in other scientific endeavors."

Kaur is collaborating with a number of individuals and organizations on the program, including Dr. Michael A. Huffman a world-renowned primatologist from Kyoto University in Japan; and Dr. Beatrice Hahn, the University of Alabama at Birmingham physician who played a leading role in demonstrating that the AIDS virus afflicting the human race originated from a virus in chimpanzees. Other groups include TANAPA, the University of Rhode Island, National University of Rwanda, Management Sciences, Inc., international tour operators and others.

Natural resources research helps HIV/AIDS victims

Those suffering from HIV/AIDS cope with the disease through the use of natural resources as a source of nutrition, income, and medicine. Barany explains, "At the household level, families afflicted by the disease have a difficult time producing the food and money necessary to meet household needs and healthcare expenses. Family breadwinners become sick and die, time needed spent farming or making money by those who are healthy is instead spent caring for ill family members, and productive assets such as farmland and cattle are sold. Ultimately, HIV/AIDS leads to deeper poverty and food insecurity. In such situations, we see that forests and non-timber forest products become an important component in household coping strategies, providing alternative sources of income and food security at low cost. At the same time, HIV/AIDS increases the demand for certain forest products, such as medicinal plants, which are an important component of affordable healthcare in Africa."

Hammett and Barany's research findings will help shape responses to the AIDS crisis. "To help others rebuild their lives after disasters such as HIV/AIDS, it's necessary to first identify what building blocks are available to work with," Hammett says. For example, to improve the strength of their immune system, rural Africans may not be able to go to a convenient store and buy a jar of multivitamins, but they may have access to an array of vitamin-rich local foods such as fruits, nuts, and game. These foods need to be part of the nutritional guidelines being established for HIV/AIDS patients in Africa.

"It's a similar situation for medicine. Drugs that can drastically improve and prolong the life of HIV/AIDS patients are simply not accessible for the majority of HIV/AIDS patients in Africa. What are available are medicinal plants that are being used to treat many of the conditions and illnesses related to HIV/AIDS. "These plants need to be a priority of natural resource conservation and management efforts, so that they remain a viable response to the HIV/AIDS crisis, which is still in its early stages." Barany stresses.

By understanding how those in regions most heavily impacted by the HIV/AIDS crisis cope, and how natural resources play into these coping strategies, Hammett and Barany hope their research will help shape aid programs assisting people suffering from the disease. Unraveling the public health benefits of forests will also draw attention to the social costs of global deforestation and the continued need for sustainable-use programs and policies, especially in the poorer regions of the world.

With support from the Africa Biodiversity Collaborative Group, Barany and Hammett have already worked toward these goals, presenting their preliminary findings in several government and international agency HIV/AIDS planning meetings and cooperating with aid programs in Africa to improve the lives of people affected by the disease.

Their efforts to put natural resources on the public health radar and represent the interests of people dependent on natural resources are taking hold as the research team has have been invited to present its work at the upcoming gathering of world health leaders for the Global Health Council's conference on "Health and the Environment."

While the program has attracted widespread interest, Hammett admits that "the HIV/AIDS-natural resource connection has been relatively uncharted territory up to now, and this has limited our ability to continue on with our research. Funding has been difficult along with the traditional mindset of institutional separation between health and natural resource sectors. Despite working towards the same goals, the health and natural resource sectors often remain separated." This is unfortunate for people whose lives are inseparable from the environment around them," laments Barany. Hammett and Barany hope to continue their research with the Tanga AIDS Working Group in Tanzania, East Africa.

Upward Bound receives $1.8 million federal grant

The Federal TRIO Programs are educational opportunity outreach programs designed to motivate and support students from disadvantaged backgrounds. TRIO includes six outreach and support programs targeted to serve and assist low-income, first-generation college, and disabled students while they progress through the academic pipeline from middle school to post-baccalaureate programs.

Thomas G. Wilson is director of the joint Upward Bound and Educational Talent Search office at Virginia Tech, which will join Outreach Program Development, part of Outreach and International Affairs, effective July 1. The Upward Bound/Talent Search office manages the two federal TRIO programs for the region, both of which target potential college students from families with parents who did not earn four-year degrees and/or with low incomes. The programs have a very high success rate, with 95% of the students from Tech's Upward Bound program and 70% of the Educational Talent Search students enrolling in college. A national survey shows Upward Bound students are four times more likely to graduate from college.

"The Upward Bound office is a good fit with our other programs that serve populations outside the university," said John E. Dooley, vice provost for Outreach and International Affairs, in announcing the grant and the merger. "Since Upward Bound guides high school students interested in attending college and Talent Search assists promising middle school, high school, and GED students up to age 27, outreach will be serving even more of Virginia's population. We hope this consolidation enables us to reach the region's youth more effectively."

Wilson is optimistic about the realignment. "Upward Bound and Talent Search are very excited to be joining Outreach and International Affairs. We look forward to forming new partnerships and collaborating on programs with more individuals and groups across the university community," he said.

Upward Bound, a federal program created in 1967, helps guide talented high school students toward a college education while improving their academic skills. It provides counseling in matching interests with abilities, choosing a career, tutoring to improve grades, training in library research techniques, selecting an appropriate college, and applying to colleges. Staff counselors visit each of the 115 Upward Bound students in 23 schools in 13 school districts once a month for individual sessions. These students must be from low income homes and/or homes in which parents did not graduate from four-year colleges.

Other Upward Bound activities include visits to the theatre, concerts, Virginia Tech athletic events, craft fairs, and trips to visit colleges. Each summer, students benefit from an introduction to the college experience during a six-week program on the Virginia Tech campus. While staying in one of the residence halls, students attend classes to help them prepare for their next year in high school, explore careers, visit other colleges, enjoy sports, go on field trips, and opt to join a choir or be part of a talent show. A spring weekend retreat on campus is also open to Upward Bound students. Workshops for parents are offered at least three times per year.

The Upward Bound program headquartered at Virginia Tech accepts students in Floyd, Franklin, Giles, Henry, Montgomery, Patrick, Pulaski, Smyth, Tazewell, and Wythe counties; and the cities of Galax, Lynchburg, and Martinsville.

Educational Talent Search, founded in 1973 to complement Upward Bound, encourages students to complete high school in a college preparatory program, choose a career, and pursue a college education. The program also helps those who have dropped out of high school obtain a GED. The Talent Search program based at Virginia Tech is fully funded by the federal government to serve 750 students from 32 schools, including seven middle schools. It is open to those between the ages of 12 and 27 who meet the same requirements as Upward Bound students. In addition to the locations served by Upward Bound, Talent Search also serves Grayson County.

Applications for both federally funded free programs are available from school counseling offices or from the Upward Bound/Talent Search office in the lower level of Hillcrest Hall, 540/231-6911. The program's web site at http://www.ubts.vt.edu has additional resources for middle and high school students.

The Upward Bound and Talent Search office was previously part of the former College of Arts and Sciences.