IEEE DistGen Stds update

IEEE SCC21 P1547 Web Site Available:

(The first is the html home page, the second one is simply an archive file log.)

The site includes a P1547Background file, a P1547MeetingPattern file explaining meeting logistics, and folders for past and ongoing notices, agendas and minutes. (Meeting minutes “annexes” are not available electronically.)

The January 2000 meeting (Albuquerque NM) minutes have just been posted at the “archives” site. <>

The next meeting is April 26-27, 2000 hosted by Cutler-Hammer in Pittsburgh PA Next after that is June 7-8, 2000, hosted by Capstone Turbines in Los Angeles

Contact is: Tom Basso, 303-384-6765,

(For additional background, see:
UFTO Note – IEEE Stds for DR Interconnection, 09 Jul 1999)


In related developments: (February 10, 2000)

Sandia’s PV News: IEEE Interconnection Standard For Utility-Intertied Photovoltaic Systems Is Approved

An IEEE-sponsored working group has developed an interconnection standard that will simplify the process of interconnecting photovoltaic systems with an electric utility. Photovoltaics (PV) is a solar-electric technology that uses solid-state solar cells to convert solar energy to electric energy. Not only does this standard vastly simplify PV interconnection, but it is the first IEEE standard of its kind for allowing utility interconnections of non-utility-owned distributed generation equipment. The unique aspects of this standard include tightly-defined requirements for the interconnecting hardware that can be tested by an independent test laboratory such as Underwriters Laboratories. This removes former barriers to PV use throughout the country.

John Stevens, Sandia National Labs, chaired the working group, which included about 25 members representing the utility industry, the PV industry, PV inverter manufacturers and PV researchers. The effort was sponsored by IEEE Standards Coordinating Committee 21 (SCC21). It required a little over three years from initial announcement of the project to final approval by the IEEE Standards Board. Its value is that it provides a standard that PV interconnection hardware can be designed to, thus removing the requirement for specialized hardware for different utility jurisdictions. The standard includes very specific requirements for systems of up to 10kW, but it covers systems of all sizes. The IEEE PV interconnection standard, identified as IEEE Std 929-2000, is known informally as IEEE 929.

The standard actually applies to the PV inverter, the device that converts the PV dc energy into utility-compatible ac energy. Similar inverters are used in other distributed generation systems such as fuel cells and microturbines. Many of the requirements for interconnection that are described in IEEE 929 might also be adopted for these other technologies.

IEEE 929 provides guidance for operating voltage and frequency windows, trip times for excursions outside these windows, requirements for waveform distortion, as well as defining a non-islanding inverter. An important parallel effort was performed at Underwriters Laboratories where a test procedure, UL 1741, was written that will verify that an inverter meets the requirements of IEEE 929.

In support of the IEEE 929 process, several development projects were completed at Sandia that addressed interconnection issues. The performance of several inverters operating in parallel when a utility line is de-energized was characterized to better understand the potential for unintended operation during a utility outage (“islanding”). A control scheme was developed to assure that islanding doesn’t happen. A test was developed to allow testing of single inverters to identify the presence, or lack, of an adequate anti-islanding scheme. Several specific tests were performed at the request of some electric utilities to examine such issues as ferroresonance with inverters under fault conditions and response of inverter protection schemes to the non-sinusoidal waveforms that are sometimes associated with abnormal conditions on utility systems.

This working group was an outstanding example of people with different backgrounds working together toward a common goal — simplifying the interconnection procedure. IEEE SCC21, which is chaired by Dick DeBlasio of NREL, has sponsored numerous PV-related standards since its inception in the late 1970s.

For further information on this PV interconnection standard
contact John Stevens,
Sandia PV Projects (505) 844-3698 (phone) (505) 844-6541 (fax)

Inverters – State-of-the-Art

Sandia’s Energy Storage Program has published a new report on power conversion systems which gives a comprehensive overview of the various design approaches, the current state of the art, and recommendations for future development (specifically targeting cost reduction).

The abstract appears below. I also have an electronic copy of the Executive Summary, which I can provide on request (specify RTF or HTML format).

To request copies, contact:
Imelda Francis, 505-844-7362, Fax 505-844-6972,

Technical contact:
Stan Atcitty, 505-284-2701,

“Summary of State-of-the-Art Power Conversion Systems
for Energy Conversion Storage Applications”

Sandia National Labs, SAND98-2019, September 1998


The power conversion system (PCS) is a vital part of many energy storage systems. It serves as the interface between the storage device, an energy source, and an AC load. This report summarizes the results of an extensive study of state-of-the-art power conversion systems used for energy storage applications. The purpose of the study was to investigate the potential for cost reduction and performance improvement in these power conversion systems and to provide recommendations for future research and development.

This report provides:
– an overview of PCS technology,
– a description of several state-of-the-art power conversion systems
and how they are used in specific applications,
– a summary of four basic configurations for the power conversion
systems used in energy storage applications,
– a discussion of PCS costs and potential cost reductions,
– a summary of the standards and codes relevant to the technology,
– recommendations for future research and development.

ORNL Utility Survey

Subject: UFTO Note — ORNL Utility Survey
Date: Wed, 09 Jul 1997 11:49:03 -0700
From: Ed Beardsworth

The Engineering Technology Division at Oak Ridge sent out a survey to a list of utilities recently, with a cover letter from Ed Fox, the division director. Some of you have already seen it, and I have the names of who it was sent to in your companies if you want them.

The stated purpose is to increase utility awareness of ORNL R&D, to obtain feedback on the relevance to utilities of that work, and on priorities for additional R&D. Also, they want stronger ties to utilities and potential users of ORNL work…a goal certainly congruent with UFTO!

Ed Fox can be reached at 423-574-0355,

The survey is being administered by:
Scott R. Penfield, Jr., Technology Insights
P.O. Box 205, Signal Mountain, TN 37377-0205
423-842-8078 Tel 500-346-9500 Alt. Tel
423-886-3225 FAX

The text of the survey is attached below, and includes a number of technologies previously reported by UFTO.

| ** UFTO ** Edward Beardsworth ** Consultant
| 951 Lincoln Ave. tel 415-328-5670
| Palo Alto CA 94301-3041 fax 415-328-5675


Part I: Current ORNL R&D Programs

The following topics briefly summarize ongoing R&D programs at ORNL. For each, please indicate whether you were previously aware of the work and provide a rating (on a scale of 1-10) as to how relevant the work is to your current needs. (If you were not previously aware of an individual R&D item, please base your rating on the summary.) If you wish further information on any topic, please so indicate.

The following technologies provide for monitoring the condition of machinery in service, on-line diagnostics for evaluating faults, plus R&D into effects of machinery aging. The objective is to relate appropriate maintenance or replacement actions to the actual condition of the machine.

1.1 Electrical Signature Analysis (ESA)
Data characterizing electrical currents and voltage waveforms to/from motors, generators and similar devices are obtained and recorded, using non-invasive probes. ORNL-developed analysis techniques are applied to the resulting data, leading to powerful insights into the health and performance of the electrical machine and the system and/or facility in which it is installed. A typical utility application involved the evaluation of transient loads in motor operated valves at a Carolina Power & Light nuclear plant. More recent developments include improved data analysis techniques and methods for the integrated monitoring of complete systems.

Status: Early forms of ESA are being used in a range of industrial applications, including utility power plants. Licensees include B&W/Framatome and ITT Movats/Westinghouse and Public Service Electric and Gas of New Jersey. More recent developments are available for licensing and/or joint development.

Previously aware of this research: _ Yes _ No
Request additional information: _
Relevance to current needs (please circle):
(Low) 1 2 3 4 5 6 7 8 9 10 (High)

1.2 Non-Intrusive Voltage and Power Factor Monitoring
ORNL is evaluating a series of new technologies for obtaining high voltage (>480V) waveforms and power factors, without contact and without the need for potential transformers. These technologies have significant potential in power quality monitoring applications.

Status: These technologies are in an early stage of development and evaluation. They are available for licensing and/or joint development.

1.3 Check Valve Monitoring
The function and health of check valves are evaluated, using a combination of magnetic and vibration sensors. Lack of adequate function and deterioration can be detected, without the need for removal or disassembly of the component.

Status: This technology has been licensed to several service vendors, including B&W/Fram- atome and ITT Movats/Westinghouse. Consolidated Edison is also a licensee.

1.4 Improved Eddy-Current Material Defect Detection
ORNL is developing a new technology for improved defect detection and imaging in non-magnetic materials. In laboratory tests, cracks in a perforated aluminum plate, located behind a 60 mil solid aluminum plate, are clearly imaged. In addition to aircraft inspection (the initial target for this innovation), steam generator tube inspection is a potential application of this new eddy-current based technique.

Status: This technology is in the early stages of development.

1.5 Effects of Aging in Machinery
ORNL has developed a vast database and associated reports on the effects of machinery aging. Information and expertise are available on the general principles of machinery aging as well as the specific effects of aging on individual components, machines and systems.

Status: The database was developed in support of NRC investigations into the effects of aging on nuclear power stations. It is available in the form of reports at the present time. Work is ongoing to develop methodologies to support condition based maintenance decisions.

ORNL’s capability for conceiving, prototyping and implementing advanced instrumentation and control (I&C) capabilities extends from the I&C support of experimental work throughout the laboratory and from supplying innovative sensor and control technologies to federal agencies, utilities and private industry. The following are examples of related utility applications.

2.1 Plug-in Compatible Instrumentation and Control Upgrades
ORNL has developed and prototyped a concept in which application-specific integrated circuits (ASIC’s) mounted on a motherboard replace corresponding analog modules originally installed in utility power plants. The simplicity of the individual ASIC’s reduces concern with common mode failures, a current issue with complex software driven systems. The resulting plug-in compatible replacement modules simplify installation and operation, because rewiring is not required and because changes to operating procedures are minimized.

Status: ORNL is supporting EPRI and the Westinghouse Owner’s Group in the advancement of this technology. A prototype safety system module has been fabricated and is currently undergoing testing.

2.2 Accurate On-Line Measurement of High Temperatures
ORNL has developed a technique for continuous in-situ calibration of resistance temperature detectors. The goal is to maintain an accuracy of 0.5% (°F) under actual operating conditions and to extend the range of useful measurement from about 900°K (1200°F), at present, to 1300°K (1800°F). A typical application would be measuring steam temperatures for on-line determination of plant efficiency.

Status: The technology has been developed to a pre-commercial form and feasibility has been established through demonstrations at the Diablo Canyon and Connecticut Yankee nuclear stations, as well as tests in the Kingston Steam Plant (EPRI I&C Facility).

2.3 Solid-State Hydrogen Sensor
ORNL and EPRI are developing a small, solid state hydrogen sensor for nuclear plant containment monitoring. Other utility applications might be in conjunction with hydrogen cooled generators, battery banks, etc.

Status: The sensor is patented and available for licensing. Tests have been conducted in air, nitrogen, argon, steam and transformer oil and for H2 concentrations of 0.5% to 30%.

2.4 Automated Measurement of EMI/RFI
ORNL has developed and used an instrument to monitor and record ambient electromagnetic interference/radio frequency interference (EMI/RFI) in power stations. The system is capable of non-obtrusive, unattended operation over several-month periods.

Status: Available now for licensing or use.

The catchy but misleading name “Chaos” has often been associated with a family of advanced non-linear time-series analysis techniques. In reality, these methods allow a degree of order to be
discerned for what otherwise appear to be a series of highly random events. Examples of practical utility applications are provided below.

3.1 Improved Combustion Control
Non-linear analysis can be used to analyze and optimize fossil power plant burners, fluidized bed combustion systems and, potentially, gas turbines for higher efficiency and improved NOx control.
Status: An early application was the characterization of fluid bed combustion systems, where an objective was to avoid unstable operating regimes (e.g., chugging). More recently, the potential of this technology for improving fossil burner control is being developed through a project involving EPRI, ORNL and B&W.

3.2 Failure Prediction
There is a further potential for applying non-linear analysis to advanced machinery diagnostics/ failure prediction (e.g., in turbine-generators). Bearings, in particular, appear to exhibit chaotic behavior in advance of certain failure modes.

Status: Non-linear analysis is being evaluated in conjunction with diagnostics and condition monitoring techniques, such as electrical signature analysis (see above). Westinghouse has expressed an interest in bearing diagnostics.


ORNL is developing technologies for automating the control of transmission systems, increasing system capacity and providing an improved understanding of the underlying costs of ancillary services.

4.1 Real-Time System Control
ORNL, DOE and EPRI are developing the technology for real-time monitoring and control of widely distributed transmission systems. This compares with current practice in which responses to disturbances are predetermined on the basis of previously completed analyses. The real-time system will employ an array of monitors, with outputs time-synchronized by satellite clocks. Artificial intelligence techniques will be used to recognize and appropriately respond to disturbances.

Status: This work is in the early stages of development.

4.2 High Capacity Transmission
ORNL has participated in R&D for increasing the capacity of high-voltage transmission lines. Included was testing of a high phase order line, which has the potential for transmitting up to three times the power of a standard single circuit AC line.

Status: The potential of this technology has been confirmed through the operation of a 1.5 mile test section, sponsored by EPRI, DOE, NYSERDA, NYSEG and ESEERCO. Given the current transition to independent operation of transmission capacity, no follow-on work has yet been identified.

4.3 Cost of Ancillary Services
One challenge in establishing the pricing basis for open access to electrical transmission systems is placing a value on ancillary services (scheduling and dispatch, load following, system protection, VARs, energy imbalance, and real power losses). Initial estimates developed by ORNL range from $1.5-$6.8/MWh, with an average of $4.1/MWh. By contrast, the FERC pro-forma schedule includes an allocation of $1/MWh for ancillary services.

Status: An initial report, based on an analysis of 12 utilities is now available. Follow-on work is recommended to establish a consistent framework for estimates.

This area includes research in power electronics, which is finding broad applicability in power quality, energy conversion and storage, adjustable speed drives, transmission, links, etc.

5.1 Resonant Snubber Inverter
The Resonant Snubber Inverter (RSI) is a power electronics innovation that employs a special resonant circuit to reduce losses during switching. Tests at ORNL have shown efficiency to be improved by 15 percentage points at half speed and 5 percentage points at rated speed. Elimination of associated voltage spikes reduces voltage stresses (leading to higher reliability), and essentially eliminates electromagnetic interference. Potential uses include power conversion for energy storage devices (e.g., flywheels, ultracapacitors, etc.) and adjustable speed drives.

Status: The RSI is currently being developed at ORNL for a number of specific applications.. The technology is available for joint development and/or licensing.

5.2 Multilevel Converter
The Multilevel Converter is another power electronics innovation that allows synthesis of high voltage waveforms, using capacitors as voltage dividers. Potential applications include DC links, static VAR generators and high voltage variable speed drives, as well as power conversion from renewable energy sources (such as photovoltaic arrays) or battery-fed systems. The ORNL technology eliminates the need for transformers, which are a significant source of cost and energy losses in conventional systems. A problem with capacitor based systems is the tendency to develop an imbalance between voltage levels when real power is being transferred (this is not a problem in static VAR generator applications). The unique contribution of ORNL is a new approach for maintaining the desired voltage balance across the capacitors, when real power is being transferred.

Status: An 11-level (21-level phase to phase) multilevel converter, employing insulated gate bipolar transistors (IGBTs) is working in the laboratory at ORNL. This system is prototypical of a 60kV multilevel converter using gate turn-off thyristors (GTOs).

This area comprises R&D on information management and operations analysis methodologies which support the management decision process.

6.1 Integrated Operational and Economic Models
ORNL has developed an extensive capability for operations and economic modeling techniques that support the management decision process. Alternative courses of action can be evaluated on a probabilistic basis, taking into account both the likelihood of various outcomes and their technical and economic consequences. Typical examples in which utilities might apply such techniques include evaluating the business potential of a new energy storage device, or determining the likelihood that a nuclear facility would be profitable over its remaining lifetime.

Status: These modeling techniques have been extensively applied. A recent example is a probabilistic assessment (for DOE) of the economic viability of each of the nuclear plants currently operating in the U.S.

6.2 Real-Time Power Scheduling
ORNL developed a “Power Advisor” to guide the operations of the Paducah, KY uranium enrichment plant in response to real-time electric power pricing inputs. The model provides a basis for deciding whether blocks of power at a given price should be accepted or whether it is more cost effective to curtail plant operations. The model includes consideration of the technical limitations of the facility, as well as the economic impact on the product bottom line.

Status: In place and operating at Paducah, KY.

6.3 Performance Indicators
The performance indicator methodology developed by ORNL is an operations management process for filtering and organizing the vast amounts of data generated in a complex management environment. The key objective is to focus management attention on activities that have the most influence on organizational goals, such as economic return, operational efficiency, safety, etc. The process starts with the selection of key performance indicators. These individual measures of performance are subjected to additional analysis and weighting, resulting in composite indices representative of overall performance, analogous to a stock market index. Feedback mechanisms are included to optimize information flow and to respond to organizational changes over time.

Status: Currently employed by DOE for managing the DOE occupational safety and health program.

The following research areas would potentially support both utility and utility customer technology support needs.

7.1 Electric Machinery Analysis
ORNL has developed an improved motor equivalent circuit model to more accurately estimate the operating characteristics of electric motors. Input to this computer-based tool can start from name plate data and increased accuracy can be obtained with supplemental calibration measurements (e.g, speed and current). Once calibrated for a given machine, the method can be used to accurately predict loads, currents, efficiency, etc. As a result, the need for additional monitoring instrumentation may be reduced in some cases.

Status: The model is complete and available through the DOE Motor Challenge Program

7.2 High Temperature Thermography
Techniques developed by ORNL offer improved capability for accurately measuring high temperatures. Using emissions from thermographic phosphors, temperatures can be measured over a wide range (cryogenic to 1600°C [2900°F]) and without the need for physical contact.

Status: This technology has been applied to several industrial processes. Initial applications have included the first stage vanes of turbine engine gas generators and the surface of steel exiting a molten zinc bath in a galvanizing process.

7.3 Electric Machinery Test Facility
ORNL has developed a flexible and well instrumented Electric Machinery Test Facility. The current capacity is 100 hp, but is now being expanded to 700 hp. During testing, loads can be varied over a wide range. Input voltage and currents can also be varied to simulate various operating demands, as well as a range of power quality situations (e.g., voltage imbalances, harmonics, etc.)

Status: The Electric Machinery Test Facility is a National User Facility available for use by private sector entities for testing and qualification of motors, generators and related components at nominal cost.

7.4 Pump Test Facility
ORNL recently commissioned a Pump Test Facility, with a design capacity of 100 hp. The configuration of the facility is highly flexible in terms of flow configuration, installed components and provisions for instrumentation and monitoring.

Status: The Pump Test Facility is a National User Facility available for use by private sector entities for testing and qualification of pumps and related components at nominal cost.

7.5 Buildings Technology Center
ORNL is actively involved in developing technologies to improve the efficiency of buildings and installed equipment. The Buildings Technology Center (BTC), established at ORNL in 1994, includes a large scale climate simulator and a hot box for testing components (walls, windows, etc.), as well as facilities for testing equipment (e.g., heating and air conditioning).

Status: The BTC is a National User Facility available for use by private sector entities for testing and qualification of building components at nominal cost.

Part II: Priorities for Additional R&D
Please indicate below up to three areas of R&D that would most help your organization to meet its objectives.

Part III: Contact for Liaison with ORNL

Please identify one or two individuals that could serve as a liaison with ORNL managers. We will keep them informed of new innovations at ORNL and request their input regarding utility R&D priorities in the future.
1. Name Title Organization
Tel FAX E-Mail

2. Name Title Organization
Tel FAX E-Mail