Superconducting Fault Current Limiter

Australians quietly develop something completely different.

A "fault" in a transmission or distribution circuit is nasty business. Circuit breakers open up, and that not only interrupts service to a lot of customers, it can also put a surge on the system. Worse, most fault clear themselves almost immediately, and then a decision has to be made, either by a person or by the equipment, whether and when to reclose the breaker. This is rough on the system, and the breakers themselves are expensive and hard to maintain.

A Fault Current Limiter (FCL) is a subtler way of dealing with momentary faults. It recognizes a sudden high current that’s not supposed to happen; it "inserts" a high impedance in the line momentarily to block that current, and returns to normal once the situation corrects itself. This is not an easy task, however. Currently (no pun), FCLs are far from ideal. Air core reactors using metallic copper conductors incur high operational losses, have limited response time, and wear out easily. What’s more, the breakers usually trip anyhow.

It’s long been recognized that FCLs are a great application for high temperature superconductors (HTSC). In fact, it’s seen as the first and best application of HTSCs on the power system. The basic idea is to put a superconducting element in the circuit in such a way that if too high a current comes along, the element goes "normal" or momentarily stops being a superconductor. This supplies the temporary high impedance to limit the current, and once the current drops, the superconductor goes back to being a superconductor and lets the current can flow again. This happens almost instantaneously, faster than a mechanical switch, and with "softer" transitions.

A SC FCL could thus detect abnormally high current transients in the grid, e.g. from lightning strikes, in a fraction of a cycle, and control the fault current so that system equipment can absorb it safely, protecting valuable downstream infrastructure.

Superconductors go "normal" if the temperature gets too high, or if the magnetic field gets too high. A SC FCL relies on the latter type of "quenching". The base current passing through the device produces a magnetic field below the level that would turn off the SC — a fault current will increase the magnetic field enough to do the trick.

SC FCLs are the subject of intense R&D efforts worldwide. ABB installed a prototype at a substation in Switzerland in 1997. The DOE is funding a new $12M program (, and EPRI is offering a major study (

A conference earlier this month presented the very latest on SC, including power applications. Note the three FCL sessions. Applied Superconductivity Conf, ASC 2004, Jacksonville, FL, October 3-8, 2004

Essentially all these efforts to date are using the bulk property of SC, and involve putting the entire load current through the SC itself, as described above. This leads to designs that are highly complex and which require a lot of SC material (i.e. very expensive wire or tape – which is proving difficult to make in large quantities). Moreover, none have progressed beyond the R&D stage and or early field beta trials. (Note – in most designs, a shunt actually supplies the impedance, not the quenched SC element, — even more complicated.)

Meanwhile, Down Under!

Meanwhile, a quiet development program in Australia has come up with a novel approach which has already been successfully demonstrated, and which is coming to North America. They developed their own SC tape and SC coils (and manufacturing method), and they invented and patented a 3-phase FCL that works in an entirely different way. It is actually more of a "controller" than a limiter of fault current.

It is a HTSC-enabled saturated magnetic core inductor. The load current passes through a copper coil on one side of a laminated-steel core. A DC coil on the other side maintains the core in a fully saturated state of magnetization. The number of copper turns are set so that a fault current in the AC coil will drive the iron core out of saturation (on the negative swing of the waveform). The coil then presents a large current controlled reactance, clipping the fault current at the design value.

All of this is explained in detail in a white paper presented in 2003, and which is available on request. Download 3.5 MB — (password required)
The design uses only a small amount of superconductor, simply to maintain the core magnetization (the only reason you need SC for this is that ordinary coils would be too big and lossy). More important, it works; it’s simple, robust, and versatile; and it will be available in a year at a reasonable price point. Key advantages include:

Superior Fault Condition Performance
– Very fast response time – protection functions activate in a fraction of a cycle.
– Large dynamic range – accommodates overloads without degradation and recovers instantly.
– Superior dynamic performance – suppresses initial transients more fully with much shorter decay times.
– Self-triggering/self-governing – operates instantly because of fundamental physical laws, no external sensing or controls required.

Low Cost
– Low operational cost – very little electrical losses in standby mode.
– High durability – very low cycle fatigue – operates through multiple operating cycles or fault events with little or no degradation.

– Expandable architecture – can be field or shop reconfigured to meet future requirements or changing grid characteristics.
– Small footprint and flexible form factor – compact to fit within space constraints and can be configured differently for local requirements.

Positive Grid Impact
– Improved grid reliability – clips fault currents completely without de-energizing the downstream grid.
– Transparency to the grid – no discernable impact during standby.

The technology has undergone substantial simulation, prototyping, and testing. The company sees no significant technical barriers and is on target to begin low-volume manufacturing and field installations of three-phase commercial units within 12 months.
The Australian company was recently acquired as a subsidiary of SC Power Systems, a US company, and operations have been moved to the US. They’ve already engaged in substantive dialogue with potential early customers and have validated the demand for its first three-phase units (15KV, nominally 10KAmps/phase).

They’ve contracted with NEETRAC (see UFTO Note 17Jan02) to prepare test procedures compatible with IEEE standards. NEETRAC member utilities are lining up to be the hosts for utility field tests scheduled for Q4, 2005. The company welcomes the opportunity to explore application needs, and will be taking orders as early as 2005.


Woody Gibson, 415-277-0179
SC Power Systems, Inc.
San Francisco, CA

The company is also raising equity funding. They presented at the NREL Industry Growth Forum, Oct. 18-20 in Orlando A business plan is available from the company.

Technology Transfer Opportunities – Oak Ridge National Laboratory



Final Report

Technology Transfer Opportunities in the Federal Laboratories

Oak Ridge National Laboratory

Oak Ridge, Tennessee

June 1998

Prepared for:

Utility Federal Technology Opportunities (UFTO)


Edward Beardsworth


Overview & Organization
Technologies & Programs

This report is part of a series examining technology opportunities at National Laboratories of possible interest to electric utilities


This report is proprietary and confidential. It is for internal use by personnel of companies that are subscribers in the UFTO multi-client program. It is not to be otherwise copied or distributed except as authorized in writing.



This report details findings about technology and technology transfer opportunities at the Oak Ridge National Laboratory that might be of strategic interest to electric utilities. It is a major update and revision materials developed previously, and is based on a visit to the lab in April 1998, and also draws from various publications, collateral information and website content.


A special note of thanks to Marilyn Brown for arranging the agenda and her gracious and tireless support, and to all the ORNL staff who gave generously of their time and attention.

Also to Mr. Scott Penfield of Technology Insights, who accompanied the visits (as a representative of one of the UFTO utilities) and kindly provided his written account of the meetings for use in the preparation this report.

ORNL — Overview & Organization

Oak Ridge National Laboratory (ORNL) is a “GOCO” lab (government-owned, contractor operated). Lockheed Martin Energy Research Corp. is the contractor that manages ORNL. (Lockheed Martin also manages the Y-12 Plant in Oak Ridge, Idaho National Engineering Lab and Sandia National Lab.)

ORNL has a matrix organizational structure, where “divisions” aligned primarily by discipline have the people, and “programs” have the projects and budgets. On some occasions, divisions do get funds and projects of their own. ORNL finds that matrix management can work well if there is a balance of power and the right incentives.

Both divisions and programs live in research “ALD’s” or Associate Laboratory Directorates, headed by Associate Lab Directors who along with other administrative and support groups report to the Laboratory Director (Alvin Trivelpiece).

ORNL’s four research ALD’s are:

=> Energy and Engineering Sciences — Gil Gilliland 423-574-9920

(Div: Engineering Technology, Fusion., Instrum & Control)

(Prog: Energy Effic/Renew Energy, Energy Technology, Fossil Energy, Nuc Technol)

=> Life Sciences and Environmental Technologies

(Div: Chemical Technol, Energy, Environmental Sci, Life Sciences)

=> Adv. Materials, Physical and Neutron Sciences

(Div: Metals & Ceramics, Physics, Solid State, Chemical/Analytical Sci . . .)

=> Computing, Robotics, and Education

(Div: Computer Science and Mathematics, Robotics and Process Systems…)

There is work in all four ALDs of potential interest to utilities. The point of contact for this study was established through the Energy Efficiency and Renewable Energy Program, which oversees activities involving 11 different research divisions. Contact was also made with the Fossil Energy Program, with a similarly broad scope. Divisions encountered include Engineering Technology, Instrumentation & Control, Metals & Ceramics, and others.

Staffing level is now at approximately 5000, of which 1500 are scientists, of which about 1/2 are PhDs. ORNL’s 1997 budget was about $550 million. Of this amount, the largest program areas were Energy Research (28%), Environmental Management (25%) and Energy Efficiency (16%). Nuclear programs, which were once the principal focus of the Laboratory, are identified at a level of 4% in the overall budget; however, when supporting research topics (e.g., High Flux Isotope Reactor (HFIR), materials, NRC Programs, etc.) are included, some $100 million can still be identified as nuclear related.

A major new initiative at ORNL is the Spallation Neutron Source facility. The 1999 budget year will constitute a major test for this project, as it will include a construction line item for the first time. If approved, construction is expected to take 6-7 years. A new ORNL directorate has been established to oversee the Spallation Neutron Source project.


Key Contacts:


Primary UFTO contact:

Energy Efficiency and Renewable Energy Program:

A.C.(Tony) Schaffhauser, Director, 423-574-4826,

Marilyn Brown, Deputy Director, 423-576-8152,

Working with ORNL:

Technology Transfer: (Licensing and CRADAs)

Dean Waters, Acting Director, Office of Technology Transfer,


Sylvester Scott, Director, Licensing, 423-576-9673,

Partnerships: (CRADAs, User Program, Personnel Exchanges, Guest Research Assignments)

Louise B. Dunlap, Director, Office of Science and Technology Partnerships,


Public Relations: Joe Culver, Director, Public Affairs,


Partnership Mechanisms

ORNL makes use of an increasingly broad array of contracting mechanisms, including CRADAs, Work for others, User Facility Agreements, etc. Greater use of simpler standard formats makes the process much quicker than in the past.

They are seeing an increasing number of “100% funds-in CRADAs” (i.e. no cost sharing by the lab) from industry, as a cheaper alternative to work-for-others with essentially equivalent intellectual property rights. The Lab also will have as many as 4000 guest assignments per year, 1/4 of which are from industry, where visitors use the facilities or work with staff on CRADAs, etc.


Energy Efficiency and Renewable Energy Program

Tony Schaffhauser, Director 423-574-4826

Marilyn Brown, Deputy Director 423-576-8152

The EE/RE Program is a matrix organization that draws on several line divisions at ORNL for the majority of its personnel and technical facility resources, to set up multi disciplinary teams. DOE is the sponsor for most of the work, but they see industry and the public as the real customer.

ORNL budget expenditures controlled through the EE/RE Program office amount to some $80 million. The ORNL Energy Efficiency/Renewable Energy (EE/RE) budget was lower in 1996, but the level now appears to be stable.

Major Research and Development Areas

=> Transportation systems, including advanced automotive technologies, advanced materials, utilization of alternative fuels including biofuels, and transportation data.

=> Efficient building systems and for state and community programs, including heating, cooling, and refrigerating equipment; roofs, walls, and foundations; insulating materials; technology transfer; and retrofit of existing residential and commercial structures.

=> Industrial processes, such as bioprocessing, electric motor systems, advanced turbine systems, advanced materials, industrial heat pumps, and evaluations of energy-related inventions.

=> Utilities, including high-temperature superconductors (for transformers and transmission cables), power transmission and distribution systems, electric and magnetic field effects, biomass for power generation, and international programs (including IEA and APEC programs).

Technologies & Programs

Superconducting Technology Program for Electric Energy Systems

Fossil Energy Technologies

Real-Time Corrosion Monitoring

Hot Gas Filters

Materials R&D

Furnace Wall Corrosion with retrofit low-NOx burners

Effects of Coal impurities on fireside corrosion

Improved Stainless Steels

“Perfect Microstructures”

Nickel-Aluminide Alloys

Sulfidation Resistant Alloys

Building Technology Center

Frostless Heat Pump

High Efficiency Refrigerator (1 kwh/day)

Power Systems Technology Program

Energy Conservation Standards for Distribution Transformers

Flywheels and Energy Storage Technologies

Utility Restructuring and Electric Power Ancillary Services

Grid Reliability-Control Center Survey

Electric and Magnetic Fields Bioeffects

Research and Public Information Dissemination (RAPID) Program

Advanced Turbine Systems

Bioenergy Program

Motor, Steam, and Compressed Air Challenge Programs

Oak Ridge Centers for Manufacturing Technology (ORCMT)

Electric Machinery Center

Power Electronics Technology Center and Inverter Technology

Instrumentation & Controls

Machine Condition Monitoring and Diagnostics

Electrical Signature Analysis (ESA) for Utility Applications

Nonlinear data analysis–Component Failure Prediction

NRC/INPO plant database

Photonics and Hybrid Lighting

Superconducting Technology Program for Electric Energy Systems

Bob Hawsey 423-574-8057

Web sites:

(See special report and series of articles on “Superconductivity in Electric Power,”

pp 18-49, IEEE Spectrum, July 1997)

The discovery of high-temperature (i.e., above the boiling temperature of liquid nitrogen) superconductor materials dates to 1986. Since that time, the challenge has been to develop these brittle, ceramic-based materials into a form that can be produced and practically used. DOE research in this area has taken a major step increase, from $19 million in 1997 to $32 million in 1998. (By comparison, Japan is investing $100 million/year in superconductor research.)

DOE HTS Program


Jim Daley, Team Leader, 202-586-1165,

or Joe Mulholland, Utility Liaison


The DOE HTS program supports a balanced technology development effort. Wire and device technologies are developed through a large number of collaborative projects between U.S. national laboratories and industry, and systems technologies are supported through the SPI and other vertically integrated project teams.

DOE’s Superconducting Partnership Initiative (SPI) is a systems technology program designed to accelerate the development of HTS electric power systems. Begun in the fall of 1993, the SPI encourages the formation of vertically integrated teams comprised of partners who usually do not interact in the development cycle, involving close collaboration among system integrators, wire and device manufacturers, end-users (typically electric utilities)

Major projects include

– 5,000 hp high-temperature superconducting (HTS) motor

– 100 MVA HTS generator,

– 115 kV and 12.5 kV HTS transmission cable (2 projects)

– 5/10 MVA HTS transformers (2 projects)

– 15 kV HTS fault current limiter (2.4 kV successfully tested in 9/95 at a utility host site)

Fault Current Limiter

Later this year, pre-commercial (alpha) prototype will be tested by So Cal Edison and Lockheed Martin. Rating is 15-kV, normal 2 kA, intercepts/reduces by 80% a 20-kA peak symmetric or 45 kA peak assymmetric fault. Also functions as a 1/2 cycle circuit breaker. If demo successful, Edison will install it at a substation, and anticipates $1million in savings from avoiding need for a second bus. Next stage will be beta units.

Contact: Eddie Leung, Lockheed Martin program manager

619-874-7945, ext. 4636,

ORNL is participating in two of these partnerships.

Transformers — There is a strong need for medium power transformers (10-150 MVA) that are smaller, more efficient and free of fire hazard, to meet the growth in urban power density. These transformers will go inside building and in multistory substations, and provide higher ratings from existing substations.

— Waukesha Electric Systems (WES), Waukesha, WI

For the Waukesha program, ORNL is responsible for the engineering, design and science of the cooling system, while Intermagnetic General is producing the HTSC coil. WES did the core, instrumentation tank, pumps and test rig. An initial 1 MVA prototype has been constructed and entered testing at WES in February 1998. Initial results are good–the first operational US HTSC transformer easily sustains 2X overloads. Rochester Gas & Electric (RG&E) and Rensselaer Polytechnic Institute (RPI) participated in this initial demonstration.

The next step will be a 5 MVA system, which will provide power to the WES plant beginning in 1999. A larger utility advisory group is participating in this second step (includes several UFTO members). The initial commercial target is a transformer in the range of 10-30 MVA.

Contact: Pat Sullivan, VP Marketing, Waukesha, 414-547-0121, x 1531.

There is a separate transformer development effort that involves ABB, EdF, Los Alamos National Lab (LANL) and American Superconductor.

Cable — HTSC Cables hold the promise of far greater capacity– 5X the power in the same 8″ diameter pipe of conventional buried cable, and without the losses, heat, oil and range limitations.

— Southwire,Carrolton, GA

The Southwire HTSC cable project is expected to culminate in an initial demonstration at Southwire in 1999. The planned 100 ft, 3-phase, 12.4 kV, 1250 Amp cable will provide power (30 MVA) to Southwire facilities. Southern Co, Georgia Transmission Co, and So Cal Edison are partners. DOE is providing half of the $14 million. Southwire has built a 200 ft clean room manufacturing facility, and recently delivered a 5 meter test cable to ORNL for testing.

Pirelli and Los Alamos are pursuing a parallel HTSC cable initiative, with participation by Detroit Edison. The initial objective is a 25 kV line.

Other HTSC development initiatives mentioned include motors/generators (including flywheel motors/generators under development at Boeing) and kaolin magnetic separation equipment being developed by Dupont for the paper industry.

NOTE- More uility participation is needed–to provide advice, and as partners, cofunders and beta test hosts. Any kind of innovative proposal is more than welcome.

RABiTS (TM) Process for Coated High-Temperature Superconductors

Oak Ridge researchers have produced a roll-textured, buffered metal, superconducting tape with a critical current density of 300,000 amperes per square centimeter in liquid nitrogen, which may pave the way for the future manufacture of practical yttrium- or thallium-based conductors for electric power applications.

To produce a superconducting wire sample, the ORNL researchers first developed a process called rolling-assisted biaxial textured substrates, or RABiTS(TM), which enables the superconducting materials to have a high degree of grain alignment in all directions, a necessary condition for more efficient current flow through the superconductor.

MicroCoating Technologies (MCT) in Atlanta and ORNL announced on April 16 that MCT has licensed key patents. “MCT scientists within a six-month period have successfully deposited both HTS coatings and oxide “buffer layers” on several single crystal oxide substrates. MCT also successfully deposited buffer layer on textured nickel. The epitaxy of some buffer layers is as good or better than with any other deposition technique to date. In addition, MCT’s open atmosphere process can meet or exceed industry-wide cost targets to enable commercial-scale production of superconductor technology.”

Other licensees include Midwest Superconductivity and Oxford Superconducting Technology, with two more pending.

Fossil Energy Technologies

Rod Judkins 423-574-4572

ORNL described some additional advancements in materials and technology for fossil and related applications that were not addressed in the ORNL survey of utilities (developed by Technology Insights and sent to UFTO members in mid 1997). Some examples are:

Real-Time Corrosion Monitoring: A flash of laser light is impinged on a fossil boiler wall. By observing the infrared response of the area, corrosion related effects, such as thinning, debonding and delamination can be inferred.

Hot Gas Filters: In partnership with manufacturers, ORNL has developed two distinct classes of hot gas clean up filters.

– A ceramic composite (SiC-based) filter developed with 3-M is primarily targeted to fluidized bed combustion applications. The filter has been tested in AEP’s Tidd Plant and a Studvik incinerator in S. Carolina. It is available through 3-M. Contact Ed Fisher, 612-736-1005

– A lower temperature (700 – 1000 deg C) iron-aluminide filter, with high resistance to sulfidation, has been developed in partnership with Pall Corp. (Portland NY) and is nearing commercial introduction. An alternative to ceramics, it can be made with standard manufacturing equipment. Tests at the University of Cinncinnati show excellent corrosion resistance. Coal gasification is the target application.

Materials R&D

Ron Bradley 423-574-6095

Ian Wright, 423-574-4451

Furnace Wall Corrosion with retrofit low-NOx burners — root cause is flame licking walls, so that control of flame characteristics using sensor-feedback arrangements should be the best solution. Hence, there is a need to develop sensors to monitor flame condition as input to control mechanism. ORNL has approaches for this, using chaos theory to analyse the flame signatures, for instance (Stuart Daw, David Schoenwald). There will also be a continuing practical need for diagnostics, coatings, repair techniques, etc., since not all boilers will be amenable to combustion control, and the use of multiple and varying coal sources will lead to continuing corrosion problems in some parts of the furnace wall. Sulfidation-resistant ferritic alloys (ORNL’s iron aluminides) promising as overlay/cladding, but difficult to apply reproducibly. Development program with Lehigh Univ-utility boiler consortium (Prof. Arnie Marder) is showing good promise.

Effects of Coal impurities on fireside corrosion — Chlorine limits based on fundamental misunderstanding–only a problem when other combustion problems (flame impingement) present. Developing in situ probes to measure short-term corrosion.

Technology Transfer Opportunities – Wright Laboratories



Final Report

Technology Transfer Opportunities in the Federal Laboratories

Wright Laboratories

U.S. Air Force

Dayton OH

February 1998

Prepared for:

Utility Federal Technology Opportunities (UFTO)


Edward Beardsworth


This report is part of a series examining technology opportunities at National Laboratories of possible interest to electric utilities


1. Summary
1 Overview & Organization
3. Technologies & Programs

This report is proprietary and confidential. It is for internal use by personnel of companies that are subscribers in the UFTO multi-client program. It is not to be otherwise copied or distributed except as authorized in writing.


This report details findings about technology and technology transfer opportunities at the Wright Laboratories that might be of strategic interest to electric utilities. It is based on a visit to the lab in June 1997 and subsequent contacts, as part of the UFTO multiclient project.


Noting the tremendous scope of research underway in the research facilities of the U.S. government, and a very strong impetus on the government’s part to foster commercial partnering with industry and applications of the technology it has developed, the UFTO program has been established as a multi-client study of the opportunities thus afforded energy utilities and their many subsidiaries.

Air Force Research Laboratory

In a major reorganization just put into effect in mid 1997, all the Air Force R&D activities were brought together into one single entity called the Air Force Research Laboratory.

From the AFRL website:


The mission of the Air Force Research Lab is to lead the discovery, development, and transition of affordable, integrated technologies for our air and space forces — to keep our Air Force "the best in the world." Our mission is executed by our nine technology directorates, located throughout the United States; the Air Force Office of Scientific Research; and our central staff. Our partners include universities and industry, with whom we invest almost 80% of our budget, and our customers include the Air Force major commands, who operate and maintain the full spectrum of Air Force weapon systems. We are a full-spectrum laboratory, responsible for planning and executing the Air Force’s entire science and technology budget: basic research , applied research, and advanced technology development. The work is done at facilities all across the country (Wright-Patt, Kirtland, Brooks, Edwards, Eglin, Tyndall, Bolling, Hanscom, Rome).

The AFRL is made up of more than 6400 government people, which includes over 1500 military and over 4800 civilian personnel. We have about 3500 scientists and engineers, of which over 800 have PhDs.


Budgets and staffing of research groups and facilities are relatively stable over time, as the Air Force regards its research capability as vital to the conduct of its overall mission, and takes a long view of its future technological needs.

• Technology Transfer

The Air Force, like all of DOD, has a strong commitment to Tech Transfer, and like DOE and other agencies,has a wide latititude of contracting mechansims and ways of working together with private industry and academia. One of the primary motivations for working with the commercial sector is to enhance the capabilities of private industry so as to lower costs to the Air Force of the high-value manufactured items they need.

The AFRL operates Tech Connect, the main point of contact for tech transfer for the entire Air Force. It provides search and contact services and facilitation.

In addition, each operating location (not just labs) have their local point of contact or ORTA (Office for Research and Technology Application).


Call – (937) 656-2530 Toll Free (800) 203-6451 FAX (937) 656-2138

Web site —

Wright Labs Overview

Wright Laboratories, located at Wright Patterson Air Force Base, Dayton OH, is oldest and largest of the Air Force research laboratories, with a history stretching back to 1917.

Wright Labs is headquarters for a number of Directorates (e.g. armament, avionics, flight dynamics, etc.).

Propulsion Directorate

One of these, the Propulsion Directorate, has the highest relevance for utilities.

The Propulsion Directorate’s work has many potential non-aerospace and commercial uses in:

– Materials and Materials Application
– Measurement and Sensing
– Modeling and Visualization
– Energy and Power

With an annual budget of about $150 Million, and about 300 mostly technical and scientific personnel, its technical divisions are:

Division – Office Symbol (Primary Site/Secondary Site)

– Power Division – AFRL/PRP (WP)
– Propulsion Sciences and Advanced Concepts Division – AFRL/PRS (Edwards/WP)
– Turbine Engine Division – AFRL/PRT (WP)
– Rocket Propulsion Division – AFRL/PRR (Edwards)
– Integration and Operations – AFRL/PRO (WPAFB/Edwards)

Principal Point of Contact: Kristen Schario, 937-255-2131,

Power Division

The Power Division plans, formulates, manages and executes research, exploratory and advanced development programs in energy conversion and storage, and power generation, transmission, conversion, and thermal management. This includes electrical, mechanical, thermal, and fluid power for aircraft, missile, terrestrial, and special Air Force applications.

Technologies & Programs

Covered in this report:

• More Electric Aircraft (MEA) 4
Power generation
Power systems and distribution components
Passive components – Capacitors
Power electronics/motor drives
• Ground Power 4
Remote Small Scale (10-120 watts)
Cryogenic Lightweight Deployable (1-4 MW)
• Turbine Compressor Research Facility 8
• Electronics Cooling
• Mechanical Testing of Electrical Machinery
• Silicon Carbide High Power Electronics
• Superconductors, Cryogenic Power Electronics
• Batteries 4
• Lubrication Technology 4

• More Electric Aircraft (MEA)

Contact: Maj. Michael Marciniak, 937-255-6226,

The Air Force has a major effort on the "More Electric Aircraft" (MEA), from which many "dual-use" applications arise. As with the more electric ship and tank, the PNGV hybrid/electric vehicle efforts share many common requirements and opportunities.

The goal of MEA is to replace hydraulic and pneumatic systems, which account for more than 1/2 of all downtime and failres of fighter aircraft, with electrical ones. A wide range of technologies are involved, including actuators, electronics cooling, motor/alternators, supercapacitors, batteries, power system controllers, and high power semiconductor devices.

The MEA will require a highly reliable, fault tolerant, autonomously controlled electrical power system to deliver high quality power to the aircraft’s loads. Also, reliable high power density motors and motor drives ranging from a few horsepower to hundreds of horsepower will be required

Military aircraft have numerous subsystems powered by one or more sources of secondary power: hydraulic, pneumatic, electrical and mechanical. Secondary power is typically extracted from the main engines mechanically by a driven shaft and pneumatically by bleeding the compressor. Mechanical power is distributed to a gearbox to drive lubrication pumps, fuel pumps, hydraulic pumps and electrical generators. Pneumatic power typically drives air turbine motors for engine start systems and environmental control systems. Electrical power and hydraulic power are distributed throughout the aircraft for driving subsystems such as flight control actuators, landing gear brakes, utility actuators, avionics, and weapon systems.

Recent and projected advancements in aircraft electrical power system and component technologies have resulted in renewed interest in the MEA. For example, hydraulically driven actuators would be replaced by electric motor driven actuators, gearbox driven fuel and lubrication pumps would be replaced by electric motor driven pumps, and a pneumatically driven compressor for environmental control would be replaced by an electric motor driven compressor. Studies on two different military fighter aircraft have shown that the MEA concept provides significant reliability, maintainability and supportability payoff.

There are four major technical thrusts in the roadmap: (1) power generation, (2) power systems and distribution components, (3) passive components, and (4) power electronics/motor drives

Power Generators — Independent Power Units (IPU)

A High Reliability Generator was developed from a conventional 400 Hz Variable Speed Constant Frequency (VSCF) system to a dual output (270 VDC and 400 Hz) system capable of supporting the near-term MEA.

The Switched Reluctance Starter/Generator program developed the preliminary design for a 375 KW, 270 VDC switched reluctance starter/generator in which the electrical machine is integrated internally with an advanced gas turbine engine.

A smaller 250 KW unit was built and tested to demonstrate the critical technologies. The switched reluctance starter/generator system offers a robust, high temperature, fault tolerant solution for the environmental demands of the turbine engine and the performance demands for the MEA.

Feasibility is based upon recent advancements in power electronic component technologies, high temperature wire insulation, and high temperature, high strength magnetic materials. The power electronic inverter is essential to the system since it provides the means to excite and process power to and from the unit. An Electro-Magnetic Interference (EMI) filter will reduce unwanted frequency components.

These systems are directly applicable to ground applications. In fact, Allied Signal is the contractor, which no doubt contributes to their civilian microturbine program.

In another development, an internally integrated 375 KW Starter/Generator for large aircraft enginees will include the critical step of eliminating the engine gearbox and aircraft mounted accessory drive. Integration into the gas turbine engine is enabled by high strength, high

temperature permanent magnet materials (cobalt-iron) and reliable high temperature wire insulation.

Power Systems and Distribution Components

The MEA will need a highly reliable, fault tolerant, autonomously controlled electrical power system to deliver high quality power from the sources to the load.

There are several challenges in designing an electrical power system for a MEA. Total onboard power requirements will be much greater, ranging as high as 1-10 MW per aircraft. It adds substantial amount of high power dynamic motor loads which could impact power quality. Most of these loads will have a low input impedance "capacitive" EMI filter which could present an in-rush current problem. Some MEA loads such as flight control actuators could provide regenerative energy back to the power distribution system.

Most important, these loads are flight critical, and loss of power to these loads could result in the loss of the aircraft. Thus, the performance and integrity of the power distribution system becomes a critical network which links sources to loads.

Presently, the Air Force has two programs for power systems and distribution components for the MEA.

– Power Management and Distribution for More Electric Aircraft (MADMEL) program
– Remote Terminal utilizing 270 VDC Solid State Power Controller program.

Future programs include development of: (a) high current (>50 ampere) intelligent power controllers and contactors that provide control, protection, and status feedback. (b) smart, overcurrent, differential current, and ground fault protection systems, (c) arc detection circuits to trigger protection devices in the event of an arc. (d) highly reliable and rugged connectors and interconnect components.

Passive Components – Capacitors

— Contact: Sandra Fries-Carr, 937-255-6016,

State-of-the-art aircraft capacitors are considered to be the weakest link in power electronic systems. They are also large, heavy and lossy. This is a real concern for the MEA since 100s to 1000s of capacitors will be required for filtering and energy storage. The Air Force is pursuing several organic and inorganic capacitor technologies under contract that promise improvements in reliability, size, weight, and electrical and thermal performance.

Foster-Miller Corp. was awarded an SBIR contract to examine the application of PBZT polymer film for capacitors. This film demonstrated dielectric strengths as high as 100,000 Volts/Mil and low dissipation factor at high temperatures (up to 300*C). A follow-on SBIR contract to Foster-Miller further developed the PBZT film to make highly reliable, high energy density capacitors with operating temperatures to 300*C.

Westinghouse Science and Technology Center was under contract to develop and demonstrate high temperature (>200*C) AC and DC filter capacitors using a FPE polymer film from 3M Corporation. The capacitors were tested with a Variable Speed Constant Frequency (VSCF) generator system and demonstrated over 2000 hours of trouble free operation at 225*C.

Olean Advanced Products, Division of AVX Corporation is under contract to develop multilayer ceramic capacitors with increased operating temperature (up to 300*C) and reduced dissipation factor over a wide frequency and temperature range. Ceramic capacitors offer tremendous volumetric density compared to other capacitor technologies.

Wright Labs, in-house, is using low temperature RF sputtering to make very thin film ceramics (600 angstroms) which can be put directly on a circuit board.

Ultra high energy density pseudo capacitors have been developed, demonstrating energy densities over 11 Joules/gram and possibly as high as 30 J/g. An inexpensive device about the size of a quarter, weighing 6 grams, is rated at 5 farads at 5 volts. These are use in burst power and other aircraft and civilian applications, and can be stacked to the 1 KV level.

Diamond Thin Film Capacitors

The Air Force is conducting an in-house research program to investigate the possibility of using diamond-like carbon and polycrystalline diamond films as dielectric materials for capacitors. Diamond has the highest thermal conductivity of any material known and a very high dielectric strength, electrical resistivity and operating temperature capability. Wright Labs has made thin films using microwave plasma-enhanced chemical vapor deposition that have very stable performance over a wide temperature range. Capacitors continue to work well at 600 deg C, with a power density of 7 Joule/gram.

The Air Force has recently awarded several contracts to investigate other promising dielectric materials and construction techniques for capacitors. This includes silicon carbide, barium titanate, and multi-layer diamond capacitors.

Power Electronics and Motor Drives

— Contact: Clarence Severt, 937-255-6235

Advancements in power semiconductor devices, capacitors, and integrated circuits for control has enabled high density, reliable power electronic and motor drive systems that are essential for the MEA. These include generators, battery chargers, DC to AC inverters, and DC to DC converters, and motor drives, which provide the interface between the electrical power system and the motor.

To date, the Air Force has focused on MOS Controlled Thyristor (MCT) switching device and the MCT driver. Future work will center on Application Specific Integrated Circuit (ASIC) technology for motor drive controls and the development of advanced drives for induction, permanent magnet, and switched reluctance motors.

In September 1986, the Air Force awarded a contract to the General Electric Corporate Research and Development Center to develop a high power MCT device. At that time, GE had only demonstrated a small MCT device capable of a few Amps and a 200 Volts. The objective of this contract was to develop and demonstrate a high power device (with several orders of magnitude increase in power handling capability) that would be applicable to aircraft power conditioning. The goal was to develop a 150 Ampere 900 Volt device capable of high speed operation (200 nanosecond turn-on and 1 microsecond turn-off capability), low forward voltage drop (1 Volt) and high temperature capability (>200*C junction temperature).

Later in the contract, an integrated circuit driver chip was developed that provides an interface between logic control signals and the gate of the MCT. This program was successful in meeting its goals, and several hundred first generation MCT devices and driver circuits were produced, with significant performance improvements as well as size and weight reductions when compared to bipolar junction transistor technology available at that time.

A second contract was awarded to GE to make the MCT an acceptable and preferred device for military weapon systems such as the MEA. This contract is focused on advanced hermetic packaging, radiation hardening, and symmetrical voltage blocking for AC applications. Also improvements to the MCT are being investigated which offer improvements in peak current turn-off capability and current density.


Ground Power

Remote Small Scale (10-120 watts)
— Contact: Tom Lamp, 937-255-6235,

The Air Force has over 80 remote sites in Alaska that need ultra high reliability power sources in the 10-30 watt range, for sensor systems, to 120 watts. Most are equipped with thermoelectric generators (TEG) that operate on propane, with some photovoltaic. The transportation costs run to $30-40 per pound of fuel, so the low efficiency of TEG, typically about 5%, is obviously a concern. Requirements are unattended operation, low health and safety risk to local population and Air Force personnel, and low environmental risk. Installation must be quick, by heliocopter drop-in. Weather conditions are very extreme.

But for the social outcry that would result, RTG’s are the obvious best choice (radionuclear thermal generators–as used on space missions). Other mature technologies include batteries, fuel cells, wind and engines, none of which meet the objectives.

Other choices are Stirling, Thermionic, Thermophotovoltaic, and AMTEC, all of which are small scale heat-to-electricity conversion devices with higher efficiency than TEG.

Stirling is under development by NASA for slightly larger systems (350 watts), and DARPA is funding some work on TPV and AMTEC ( a 500 watt compact system for the Army).

For the Alaska sites, the conclusions are that AMTEC and Stirling are the best candidates. Work is underway to develop prototype systems, building on the work done for space power systems. Commercial applications could include gas metering, navigation stations, weather monitors, and cathodic protection.

Cryogenic Lightweight Deployable (1-4 MW)
— Contact Jerry Beam, 937-255-6226

The Air Force needs lightweight deployable power plants to support, as one example, ground based radar (GBR) systems. Conventional technology and it’s supporting infrastructure is larger and heavier than wanted, and one of the Air Force’s key goal is to reduce the "logistics tail" whenever possible. A study showed that the conventional GBR plant with 5 semi-trailers and 140 cubic meters in volume, could be reduced to 2 trailers by the use of a superconducting cryogenic power generator. Since the radars already need cryogenic support, this is not an additional requirement, and the size and efficiency gains are significant. A prototype system will be tested in 2000, and could be in the field by 2005.

Turbine Compressor Research Facility (CRF)
— Contact: Mark Reitz, 937-255-6802

The CRF is a major facility for conducting tests and evaluations of full scale multi stage and single shaft fans and compressors for gas turbine engines. Extending over four buildings, it is capable of 30,000 hp at speeds to 16,000 rpm, and 15,000 hp from 16 to 30,000 rpm. It can create steady-state and transient phenomena on full size test articles under conditions that are similar to those of actual operation. It has been used for many advanced turbine development programs to evaluate fans and core compressors.

Solar Turbines, Inc. is developing gas fired turbine engines for cogeneration and industrial drive applications in industry, under a CRADA with DOE’s advanced turbine program. The compressor for this engine is now under test at the CRF to identify any possible design deficiencies. This is the first major commercial use of the CRF.

Electronics Cooling
— Contact John Leland, 937-255-2922

Cooling of power electronics is particularly important as systems become more compact and powerful. Anticipating cooling requirements up to 600 W/sq cm, a number of initiatives at the Lab include:

— testing performance of heat pipes in aircraft-type environments, e.g. under acceleration and vibration. Contact Kirk Yerkes, 937-255-6241
— integration of direct spray cooling into a 270 V 400 A single phase inverter, leading to a reduction in size of 10X. Direct immersion, jet impingement and flow boiling are also receiving attention. Contact Brian Donovan, 937-255-6241
— Venturi flow cooling is another technique under consideration

Mechanical Testing of Electrical Machinery
— Contact Tim Young
— Characterization of soft magnetic materials at higher speeds and temperatures encountered in IPU’s
— Windage in generators can become a significant power loss (as much as 30-40%) at high RPM due to viscous air losses.

Silicon Carbide High Power Electronics
— Contact: Clarence Severt, 937-255-6235

Compared with silicon, Silicon Carbide semiconductors have 3 times the band gap, and a operating temperature range reaching 4-600 deg. C, compared with 125 deg. C for silicon. It also has higher breakdown strength, which can mean thinner devices. Also, increased circuit efficiencies can reduce heat loads as much as 5X.

The main obstacle to using SiC in power electronics is the difficulty in making it without defects. "Micropipes" form too easily as the material is built up by vapor deposition.

The Air Force program has focused on development of high quality semiconductor grade material, improving on both wafer size and defect rates, for an aggressive development effort for power electronic devices. They have set a goal to demonstrate a 100-amp 600-V 572 deg F SiC switch by the year 2002.

For the power industry, discussions were well along with EPRI last year on possible cofunding of several device programs, but EPRI backed out. No new initiatives have come forward since.

——press release by CREE Research, one of the key developers in this program——–

Cree Unveils New Product Offerings for Silicon Carbide Wafers 40% Reduction in Micropipe Densities on Silicon Carbide Material

(Durham, NC May 27, 1997) Cree Research Inc. [NASDAQ: CREE] today announced that it has made tremendous progress in its efforts to reduce micropipes within its silicon carbide (SiC) material. Cree will now offer its 4HN type SiC wafers with reduced micropipe densities (MPD) and graded to three categories. The low grade will have a maximum of 30 micropipes/cm2, which represents a reduction in MPD of 40%. A new select grade will be added, which will have a range of 31 to 100 micropipes/cm2. In addition to Cree’s low and select grades, the standard grade will have a range of 101 to 200 micropipes/cm2. This represents a reduction in MPD of 50%.

Christer Ovren, Director of Silicon Carbide Device Development at Asea Brown Bovari (ABB), commented that "Cree continues to lead the world in making lower micropipe substrates available for the research and development of next generation devices. This latest advance is another step forward in maturing the manufacturing process for silicon carbide technology." ABB has purchased SiC wafers from Cree for a number of years.

These reduced micropipe densities are a result of Cree’s continuous commercialization of its SiC material technology. Cree expects this technology breakthrough to enable SiC material for more applications and improve device performance of existing applications. North Carolina based Cree Research, Inc. is the world leader in the development of silicon carbide-based semiconductors which have potential advantages in certain optoelectronic, RF and microwave, power, and high temperature applications. Cree owns outright or licenses exclusively 40 patents related to its process and device technology.


Superconductors, Cryogenic Power Electronics
— Contact: Charles Oberly, 937-255-4814

As noted above, cryogenic systems can have dramatically improved efficiency, size reduction, and performance as compared with standard counterparts. Power conversion efficiency of an alternator/motor, for example, can reach 99%, including the refrigeration needed, compared with 92% for conventional copper based components. Wright Lab is developing both the high temperature SC materials and designs for generators, motors, actuators and power transmission lines.

Perhaps less well recognized, cryogenic cooling (i.e. to liquid Nitrogen temperatures) dramatically improve the performance of standard commercial solid state electronic components. Devices such as MOSFETS exhibit significantly reduced heating and faster switching. Ceramic capacitors have lower losses and higher capacitance when cooled.

— Contact Steve Vukson 937-255-7770, Dick Marsh

Aircraft battery systems are a major concern, particularly in regard to weight, reliability and maintenance. For example, vented NiCd battery maintenance costs are $3000/yr for each battery, amounting to $1/2 billion over a 20 year period. Wright Labs has developed a maintenance-free sealed NiCd cell technology, which uses low cost separator materials and which they’ve married with a microprocessor-based smart charger. These new systems will eliminate all scheduled maintenance costs, and also to save another $1/2 billion by reducing flight mission interruptions.

The bulk of the Lab’s battery program budget is devoted to advanced lithium polymer technology, doing work in molecular engineering in cooperations with Cornell, Berkeley and other academic institutions. The program has demonstrated prototype rechargeable lithium batteries with energy densities above 80 W-Hr/kg.

Thermal batteries are a special class of one-shot primary batteries used in weapons systems to deliver a large burst of power, very reliably, after waiting as long as one or two decades. Sandia National Lab is also well versed in this technology. ( –Would this have a useful role to play in nuclear power plant emergency systems?)

Lubrication Technologies
— Contact Bob Wright, 937-255-4230,

This separate branch provides field support, development and advanced technology research. Their services to the Air Force include comprehensive testing facilities, bearing systems development, lubricant testing, magnetic bearings, etc.

For lubricants, increasing operating temperatures and longevity of lubricants are ever present goals. Some state-of-the-art compounds (polyphenyl ethers) have higher temperature capability but cannot be used below 40 deg. F, an obvious limitation for tactical systems. Others (perfluoro ethers) perform extremely well over a wide temperature range, but degrade quickly leading to corrosion. The overall paradigm is shifting from use of bulk oils to vapor phase lubricants, soft magnetic materials, and expendable coatings, although conventional ester lubricants are still foreseen to be the mainstay of aviation lubrication for some time to come. Meanwhile, integration of on-engine (on-line) oil condition diagnostics is an important theme. Off-line diagnostics are effective, but not optimal. This is a vital issue, as lubricant systems are implicated in 1.5 aircraft losses per year.

Magnetic Bearings — The Lab has a major development program, foreseeing big opportunities in engines to do active rotor dynamics control, increase temperature, do active control of compressor stability and blade tip clearance, and to have less logistics and better real time diagnostics.

On-line spectrometer — The Lab is sponsoring development of a very small infrared spectrometer for on-line oil analysis. The device measures the condition of the basestock and additives, and can detect the presence of unwanted contaminants, such as water, fuel, glycol, or wrong oil type.


"RULER" — Remaining Useful Life Evaluation Routine — off-line test system measures antioxidant levels in lubricants quickly and accurately by "voltammetric analysis". Results enable operators to determine remaining useful life of lubricants in less that a minute. RULER System consists of an "RULER" — Remaining Useful Life Evaluation Routine — off-line test system measures antioxidant levels in lubricants quickly and accurately by "voltammetric analysis". Results enable operators to determine remaining useful life of lubricants in less that a minute. RULER System consists of an instrument with probe, R-DAS (RULER Data Acquistion Software) pre-installed on a desktop or laptop computer. RULER System cost about $15,000. Proprietary solvents are used in the tests.

The RULER was originally developed at the University of Dayton Research Institute for Wright-Patterson Labs, for quick tests on aircraft oils between missions. It is manufactured by Fluitec Ltd., based in Dayton, OH with operations in Brussels. RULER customers cover a large range of industries world wide in oil, additive, manufacturing plants, power generation, aerospace and fleets. It’s applied to turbine, hydraulic, synthetic, working fluid, IC engine, and even biodegradable oils.

Contact: Lawrence Contreras, Fluitec, 937-223-8602,

Room Temp Superconductor Wire

Subject: UFTO Note — Room Temp Superconductor Wire
Date: Tue, 22 Oct 1996 12:46:46 -0700
From: Ed Beardsworth <>
| * UFTO * Edward Beardsworth * Consultant
| 951 Lincoln Ave. tel 415-328-5670
| Palo Alto CA 94301-3041 fax 415-328-5675

ROOTS, Inc. — Room Temp Superconductors (again)

References: previous UFTO notes about this company:
Aug 27, 1996 Private placement offering memo
May 23, 1996 Update on progress
March 1995 First UFTO report

The credibility of this story appears to be increasing substantially.

ROOTS Inc. has established the presence of very high conductivity in certain classes of polypropylene polymer films, and is actively developing applications for the film, while also working on making wire. The materials exhibit near zero resistivity, several orders of magnitude less than copper, from -450 to +390 degrees F.

ROOTS has completed a phase 1 SBIR with the Air Force, and began a Phase 2 contract in May.

Dr. James L. Smith, Chief Scientist at the Superconductivity Center at Los Alamos National Lab, has recently joined their Scientific Advisory Group, and has clearly indicated that he takes their work very seriously.

The company now has prepared a detailed development plan to build “ultraconductor” wire, one kilometer long, and they recently submitted a proposal for an NIST/ATP grant for $2 million.

This new plan provides the clearest picture of what is happening, including a readable outline of the theory. A copy can be obtained from ROOTS under a non-disclosure agreement.
Contact Mark Goldes, ROOTS, Sebastopol, CA, 707-829-9391.

Bulletin #9 – Intelligent Distribution Geomagnetic storms Superconductivity

UFTO Bulletin #9
July 13, 1995

To: UFTO Subscribers:

. . in this issue: . . . . . . . . .

Intelligent Distribution Geomagnetic storms Superconductivity


1. Update on the new connection at Idaho National Engineering Lab(INEL)…….

– I’ve waited sending this to include a more detailed description of the”Intelligent Distribution System” but INEL hasn’t gotten it to me yet. I’ll send it on to you Friday if it arrives. On the surface, the “IDS” looks like a perfect match for your company’s strategic goals, so be sure to alert the appropriate people in your company.

– INEL is probably not going to do the big “Utility Day” mentioned previously. Instead, they’d welcome visits by any of us individually or in groups (which is even better for us). I will plan my official UFTO visit for sometime in August. Maybe you’d like to join me there after I’ve spent a day with them, or arrange for a visit some other time, once I get you more information.

2. Changing Faces: Just after I sent you the list of lab contacts, I learned that David South is no longer at Argonne. He left to join a consulting firm in DC with Jack Siegel, former head of DOE Fossil. Until we reestablish contact with that part of ANL, we can continue to work through Tom Marciniak.

3. DOE’s Annual Peer Review of the Superconductivity Program of Electric Systems will be held August 1-2 at the Holdiay Inn, Alexandria VA. Contact Craig Matzdorf, Energetics, Inc., 410-290-0370. The program will cover national lab and major private industry programs and detailed project updates from the Superconductivity Partnership Initiative. Looks like a good way to get the whole story at once! I have a copy of the agenda if they can’t get it to you immediately.

– (Are you getting the Superconductivity Bulletin? I sent them your name and address. Contact is Margaret Hanley at Argonne National Lab, Email:

4. Any interest in geomagnetic storms, solar flares, and that whole business of induced EM pulses raising havoc with T&D systems? An episode in 1989 blacked out the entire Hydro Quebec system. Sandia has done some work in what they call “Space Weather Modeling” (I have a copy of a report and a contact name). Also, Oak Ridge has an ongoing monitoring project. Let me know if someone in your company wants to follow up.

– (BTW–Sandia is reviewing my draft report, so it should be ready before the end of July)

5. I will be travelling July 16-21 to the UBG meeting and the 5th International Conf. on Batteries for Utility Storage. A UFTO member utility is sending me to represent them and to take detailed notes. If you want to cofund this fact finding mission and share in the results (as this is outside the scope of UFTO), let me know.

The hotel tel # 800-468-2818 or 809-791-1000 if you want to reach me.

6. The time is rapidly approaching to decide about Year #2 of UFTO. A letter and proposal went in the mail to you this week. We have one confirmed renewal already! Let me know if there’s anything I can do to help your decision process.