Posts

DOE Office of Electric Transmission & Distribution (OETD)

/0 Comments/in , /by

Back in March, we thought announcements were imminent. (See UFTO Note ? T&D R&D Gaining Attention, 21 Mar 2003.) Little did we realize the kinds of struggles that would ensue internally in DOE over which people, programs and budgets would be won or lost by which office. The new office started its work nonetheless, judging from numerous appearances by its chief, Jimmy Glotfelty, and several planning and roadmapping meetings over the spring and summer. And the dust has settled internally.

OETD officially “stood up” on August 10, but the big August 14th blackout made for awkward timing for a press release–none has been issued. (In fact, until an appropriations bill passes, I’m told they aren’t actually officially “up”.)

A new website quietly appeared on August 21. If offers a first cut at describing the Office and its scope of responsibilities and giving links to planning documents:

http://www.electricity.doe.gov/

[This site has a good compendium of information on the blackout, however for the 12 Sept announcement of the release of a report on the events sequence, go to the DOE home page, www.energy.gov.]

**National Electric Delivery Technologies Vision and Roadmap**
There’ve been two major meetings this year, one in April and one in July. In chronological order:

~~~
April 2003 Vision Meeting Proceedings (PDF 1.1 MB)
[65 people attended, of whom only 8 represented utilities]
http://www.energetics.com/meetings/electric/pdfs/presentations/proceedings.pdf

Results of the April meeting are given in this vision document**. [The results of the July meeting will be reported in a few more weeks.]:

“Grid 2030” — “A National Vision for Electricity’s Second 100 Years,
A CALL FOR LEADERSHIP”

**DOE’s National Electric Vision Document
(Final version, July 31, 2003) (PDF 1.2 MB)
http://www.energetics.com/meetings/electric/pdfs/electric_vision.pdf

~~~
Proceedings for National Electric Delivery Technologies Roadmap,
July 8-9, 2003 (PDF 1.0 MB)
[About 20 utilities were represented, with less than 40 people out of 200 participants.]
http://www.energetics.com/meetings/electric/pdfs/proceedings.pdf

~~~
Glotfelty’s kickoff presentation July 8:
“Transforming the Grid to Revolutionize Electric Power in North America”
http://www.electricity.doe.gov/documents/glotfelty roadmap opening 07 08 03.pdf

~~~~~~~~~~

No personnel are identified on the new website (other than Gotfelty and Bill Parks, Assistant Director), and no org charts shown. The most complete descriptions of the programs appear in a series of factsheets:
http://www.electricity.doe.gov/documents/
http://www.electricity.doe.gov/documents/OETD_factsheet.pdf

The work of OETD follows these earlier developments: (see reliability program materials at http://www.eere.energy.gov/der/transmission/)

— The National Energy Policy (May 2001) calls for the Department of Energy to address constraints in electric transmission and relieve bottlenecks.

— The National Transmission Grid Study (May 2002) contains 51 recommendations for accomplishing the President’s National Energy Policy and speeding the pace of the transition to competitive regional electricity markets.

— The Transmission Grid Solutions Report (September 2002) provides guidance for priority actions to address congestion on “national interest” transmission corridors.

OETD conducts research in several areas:
–High-Temperature Superconductivity
–Electric Distribution Transformation
–Energy Storage
–Transmission Reliability

One participant at the July meeting told me he thought that DOE seems to be in the thrall of superconductors and other mega-technology solutions, and giving short shrift to distributed generation, microgrids, and other common sense approaches.

As for budget, through the end of Sept (FY03), OETD is operating on funds already committed to the programs that were brought in. Of roughly $85 Million in FY’03, high temperature superconductors have $40 M, and $27M was subject to Congressional earmarks. The FY04 budget request has a new line item for electric power infrastructure, and hopefully will provide more resources in FY05) explicitly for transmission reliability. Another observer said that the future program will be more balanced as a result.

The R&D plan is based on a 3-level architecture:
1. “Supergrid”, or coast to coast backbone for power exchange. (superconducting)
2. RegionGrid
3. CityGrid, ultimately involving fully integrated 2-way power flow, microgrids, etc.

Planning and analysis tools are needed at all 3 levels. The Supergrid is a longer term goal, operational perhaps in 10-15 years. Other near term elements include sensors, storage, and DC systems.

T&D R&D Gaining Attention

/0 Comments/in , /by

Here are some high-level pointers to an array of resources related to ongoing developments in T&D research, sponsored by DOE, NSF and the CEC (Calif Energy Commission), which demonstrate a new level of attention to grid reliability and security.

Let me know if I can be helpful digging deeper into any of these areas.

~~~~~~~~~~~~~~~

DOE – Office of Electricity Transmission and Distribution

The Dept. of Energy will announce, perhaps as early as next week, the creation of a new office for T&D reporting directly to the Secretary, as recommended in the National Transmission Grid Study* done last year. The Office of Electricity Transmission and Distribution will start with a budget of $85 million, however all but $8 or 9 million is already committed to earmarks ($27 M) and high temperature superconductors ($40 M). The office will be headed by Jimmy Glotfelty, an assistant to Abrahams. The staff currently in the Transmission Reliability Program in EERE will move over to the new office.

Meanwhile next week, a new Center will be dedicated at Oak Ridge:
http://www.ornl.gov/ORNL/Energy_Eff/nttrcdedication.htm

The dedication of the National Transmission Technology Research Center (NTTRC) and the Powerline Conductor Accelerated Facility (PCAT), the first working facility of four planned for the Center, will be held March 25. The Center, sponsored by ORNL, DOE, and TVA, will test and evaluate advanced technologies, including conductors, sensors and controls, and power electronics, under a wide range of electrical conditions without jeopardizing normal operations. The first component of the NTTRC, the PCAT facility, is initiating its first test protocol with 3M’s advanced Aluminum Conductor Composite Reinforced conductor.
— Overview of NTTRC:
http://www.ornl.gov/ORNL/Energy_Eff/PDFs/NTTRCoverview.pdf

The existing Transmission Reliability Program was reestablished by Congress in 1999 to conduct research on the reliability of the Nation’s electricity infrastructure during the transition to competitive markets under restructuring.

http://www.eere.energy.gov/der/transmission/
Go to “Documents and Resources” for recent studies and materials.

*(May 2002 http://www.energy.gov/NTGS/reports.html)

~~~~~~~~~~~~~~~

Calif Energy Commission

The CEC Public Interest Energy Research program (PIER) has a very active effort underway in Transmission Research. They recently released a 140 page “Electricity Transmission Research and Development Assessment and Gap Analysis – Draft Consultant Report” — now available online along with other materials and presentations:
http://www.energy.ca.gov/pier/strat/strat_research_trans6.html

This report is one of two reports which were discussed at a public workshop held March 12, 2003 at the CEC.

~~~~~~~~~~~~~~~

National Science Foundation
Directorate for Engineering, Elec. And Communications Systems
http://www.eng.nsf.gov/ecs/

1. Workshop on Modernizing the Electric Power Grid, Nov 02
— http://eent1.tamu.edu/nsfw/index.htm

Starting on slide 14 of James Momoh’s presentation there is a good overview of the EPNES initiative (next item)
http://eent1.tamu.edu/nsfw/documents/Presentation_JMo.ppt

2. NSF/ONR Partnership in Electric Power Networks Efficiency and Security (EPNES)
http://www.nsf.gov/pubs/2002/nsf02188/nsf02188.htm

This solicitation seeks to obtain major advances in the integration of new concepts in control, modeling, component technology, social and economics theories for electrical power networks’ efficiency and security. It also encourages development of new interdisciplinary research-based curriculum… Proposals were due Feb 3.

3. The Power Systems Engineering Research Center (PSERC)
PSERC is an NSF Industry/University Cooperative Research Center, involving a consortium of13 universities working with government and industry. The website has a huge array of reports and publications.
http://www.pserc.wisc.edu/

For the NSF’s “fact sheet”, see:
http://www.nsf.gov/pubs/2002/nsf01168/nsf01168ee.htm

Optic Fiber Inside Transm Cable Measures Temperature

/0 Comments/in , /by

Here is most of the text of a summary prepared by the developers, Com Ed and Southwire. The complete Word document with graphics can be downloaded at:
http://www.ufto.com/clients-only/fotc.doc (password needed)

~~~~~~~~~~~~~~~~~~
**ComEd – Southwire Alliance Develops Novel Fiber Optic Transmission Conductor (FOTC)

In 1999, ComEd began work with Southwire to investigate a new concept to accurately determine the thermal behavior of overhead transmission lines during operation. It is the conductor temperature that dictates the thermal rating and available clearance under a line. However, as of yet no satisfactory method has been developed that measures conductor temperature axially throughout its length as well as radially.

A novel overhead transmission conductor system that uses optical fibers as an integral part of the phase conductor has been developed by ComEd and Southwire (Patent Pending) and placed in service on the ComEd system.

Operational since February 21, 2002, the 138 kV FOTC system uses distributed temperature sensing (DTS) to measure the temperature of the optical fibers that are embedded in the conductor. DTS allows accurate temperature measurement along the entire length of the FOTC line at different locations within the conductor.

Prior to the field demo, the FOTC system was tested and characterized by the NEETRAC {see UFTO Note, 17Jan02} and Oak Ridge National Lab (ORNL). Significant discoveries on the temperature behavior of the transmission conductor under various test conditions were found. For example, the impact of wind on radial temperature drop across a conductor and the impact of solar radiation on a conductor varied significantly from IEEE Std 738 during extreme weather conditions.

Field Trial Installation: The Fiber Optic Transmission Conductor (FOTC) was installed using a special dead-end assembly and an optical insulator. The installation method was the same as a conventional one, except that special care was taken to separate and protect the optical fibers from the conductor at the dead-end location.

The graph shows an example of the temperature data that is available in real-time from the FOTC system. With the FOTC system it is a simple matter to show the temperature of any desired interval lengths of the FOTC line. [graphic: Temperature versus Time Profile of 138 kV FOTC Line]

Utilities have a need to maximize the use of their assets. FOTC provides the medium for utilities to determine the real-time thermal operating limit of a transmission conductor in the most accurate way possible. It also provides the means to transmit data or voice communications. As the utility industry continues to evolve through transmission open access, new innovations such as FOTC will help pave the way to competitive advantage.

~~~~~~~~~~~~~~~~~~

Southwire will pursue the development and commercialization of FOTC under a license from ComEd. A market study is underway, and in particular the partners want to learn more about how much FOTC can increase transmission capacity, and how utilities will judge the merits and value for use on their own systems.

Contacts for Additional Information
Jim Crane, ComEd, 630-576-7034, james.crane@exeloncorp.com
Gene Sanders, Southwire, 770-832-4988, gene_sanders@southwire.com

Sag Line Mitigator Update

/0 Comments/in , /by

Progress is excellent.

1. Utility Lineman Perspective:
2. Revised Test Plan
3. Opportunities

———–background info—————
Previous UFTO Notes:

— Sagging Line Mitigator; Mon, 08 Mar 1999

This unique device would replace or work with standard insulated hangers on power transmission towers, to counteract the effect of temperature on the sagging of overhead transmission lines. This allows increased line ampacity (load current capacity) of existing lines during curtailed summer months, reduced tower heights, and/or increased tower spacing. This device will significantly reduce the risk of forest fires and outages caused by sagging lines, increase the efficiency of energy transfer, delay the need for additional line capacity, and delay the construction of new lines.

— T Line Sag Mitigator Gets Funding; Partner Wanted; Tue, 29 Jun 1999

— US Patent No. 5792983 Aug. 11, 1998
SAG COMPENSATOR FOR SUSPENDED LINES USING ROTARY MOTION
Abstract: The invention used devices that change in length as a function of temperature to mitigate sag in a suspended line. The devices have actuators which change in length as a function of temperature. This change in length is transferred to a linkage mechanism, such as a cog or disc, which amplifies the change in length and changes it to rotational motion that tensions the suspended line. Therefore, the same change in temperature that causes the suspended line to sag will cause the device to actuate a rotary motion that reduces line sag.
———————————

Progress is excellent.

1. Utility Lineman Perspective:

Earlier this month, the construction coordinator for T&D reliability at a major utility visited the company to discuss the role of a Lineman in transmission line work and to provide input on the current SLiM design, functionality, and its proposed installation procedure.

The visit began with a review of the SLiM overall concept, the current design status, and current challenges, providing the relevant information he needed to evaluate the device from a Lineman’s perspective. After seeing the 3D computer animation of the SLiM models and the full-size mockup, he was very optimistic about how SLiM would be received by both T&D operators and lineman: “…if this device does what it is designed to do, it should sell like hot cakes!…” His view on the installability of the device was that it would be relatively simple to do using existing installation procedures and equipment.

The second topic of discussion involved a detailed review of installation procedures for SLiM and line attachment hardware. Previously three methods of line contact had been identified for SLiM: compression dead-end, preformed dead-end, and mechanical jaw grip dead-end. Based on this meeting, two methods of attachment were considered as the most common to be used by utilities; compression dead-end and strain clamp dead-end (new, not previously considered). Each attachment method would have its own installation procedure for live line work; “Bare Hand” technique and “Hot Sticking” technique respectively. These procedures will be outlined in detail in a future report once they are completed.

Conclusions/actions:
– The SLiM concept was seen as a very attractive method of resolving sag related issues,
– The SLiM device would require nothing more than standard installation procedures and equipment, and
– General guidelines will be developed for SLiM installation techniques using utility experience and knowledge.

2. Revised Test Plan

To demonstrate the functionality and integrity of the device, the company has decided to replace the original plan to test the device in the field with a host utility, with a plan to do controlled tests in a laboratory setting.

Reasons for the change– field testing appears not to be feasible, and won’t get the needed information:
– Field testing at a remote site does not allow sufficiently close testing control to measure all relevant parameters at the right time.
– Field testing on a real line significantly limits our response and our ability to efficiently implement design changes that may be required (and are identified) as a result of testing.
– Field testing, most probably, will not impose the device to the extreme conditions at which it needs to be tested. Furthermore, it only would test for a specific environment that is not applicable to other conditions.
– Convincing a utility to install these devices on heavily transit lines in nearly impossible and installing them on light-duty loads would be almost useless.

The new plan:

— Utility Survey and Testing Site.
The objective of this new task will be to conduct a utility survey, generate awareness and interest amongst utilities about the product, and solicit a host siting for part of testing.

— Conduct lab and field testing, improve/optimize designs, finalize the product design.
The test plan will be implemented by a series of lab and “field” testing. These tests will be conducted “interactively” in environments that are controllable and manageable. Test results will be used to improve designs and retest if necessary. The final outcome of this task will be a device or a family of devices which will have passed all testing requirements such that they will function as intended when installed on actual power lines.

3. Opportunities

1. Suggestions for who might be able to help them with the survey?
2. Active participation in the development– advisory, in-kind, investment, testing.
3. Suitable lab needed- business arrangements to be determined. An RFP will be issued in a few weeks. Let me know if you’re interested.

CONTACT:
Contact: Dr. Manuchehr Shirmodhamadi
Material Integrity Solutions, Inc., Berkeley, CA
510-594-0300 x202 mshir@misolution.com

T Line Sag Mitigator Gets Funding; Partner Wanted

/0 Comments/in , /by

Recall this UFTO Note?
————-

Subject: UFTO Note – Sagging Line Mitigator
Date: Mon, 08 Mar 1999

This unique device would replace or work with standard insulated hangers on power transmission towers, to counteract the effect of temperature on the sagging of overhead transmission lines. This allows increased line ampacity (load current capacity) of existing lines during curtailed summer months, reduced tower heights, and/or increased tower spacing. This device will significantly reduce the risk of forest fires and outages caused by sagging lines, increase the efficiency of energy transfer, delay the need for additional line capacity, and delay the construction of new lines.
————–
The developers now have substantial funding from the Calif Energy Commission to proceed with development, and they are looking for a host utility to be involved.

They’re proposing that a utility would provide the electrical engineering person(s) they need for the development team. They would cover part of salary and incremental costs. A “recruitment” notice appears below. Other business arrangements are also certainly possible. The important thing for them is to get industry expertise, and for the utility, early access to a possibly very significant transmission system innovation.

—————————-
In my own discussions about this with some utility folks, the value of this device hasn’t been immediately obvious, so I asked the company about it. Here is their reply:

Question: How often is sag an important limitation?

Answer: Some lines are designed w/sag limits and some w/temperature limits (which again relate back together!). Also, there are lines for which winter loads (cold) are an issue (lack of sag – high tension). Our device would keep sag practically constant and hence will help these conditions. Benefits of such a device which keeps line profile constant are numerous and not all of them are obvious. In our contacts with transmission line experts, we have generally received favorable reposnse, however, I have also noticed that the benefits of the device may not be obvious to some. That, I believe, maybe because they consider load curtailment as part of design. However, from a designer/planner point of view, slim would make it possbile to increase those ampacities, which would lead to significant benefits.

SLiM can also solve a multitude of temperature related issues with these lines, including mitigation of fatigue loading/failures and reduction of high tensile loads during cold ice storms.
———————

Material Integrity Solutions, Inc., specializes in mechanical and structural analysis and design of complex components for a number of industries including power generation, gas transmission, electronics, and manufacturing. The company is seeking partnerships and expertise in conductor and transmission system design, for development of the SLiM device.

Experience Requirements

Applicants must have excellent knowledge, expertise, and experience, as demonstrated by minimum of 5 years of utility transmission design and/or construction, in:

– Electrical and electromagnetic analysis/design of overhead transmission systems
– Design and analysis, technical and economic, of overhead transmission
systems including conductors, insulators, and towers
– Computer modeling of overhead transmission components for simulating
their electromagnetic behavior particularly in evaluation of their corona performance
– Materials used in and their behavior for overhead transmission systems
– Issues related to maintenance and integrity of overhead transmission systems
– Familiarity with Codes and Standards and knowledge of technical
committees applicable to transmission lines
– A minimum of B.S. degree in electrical engineering or equivalent
and excellent written communication skills are required.

The position is for a 1-2 year involvement in a multi-disciplinary team whose goal is to design, test, fabricate and market a new line of patented components for electrical transmission lines. The individual will be a key member of our team and will bring the expertise delineated above to the project and contribute to the successful implementation of this design. Therefore, the applicant must be highly motivated and self-directed, a hard worker, a fast learner, and a team player. The actual work will be performed at both our offices and applicant’s organization offices.

Contact: Dr. Manuchehr Shirmodhamadi
Material Integrity Solutions, Inc., Berkeley, CA
510-594-0300 mshir@misolution.com
http://www.misolution.com

POLUX – Non Destructive Wood Pole Inspection

/0 Comments/in , /by

The POLUX system of wood pole inspection is a new non-destructive evaluation (NDE) technology that is being increasingly used worldwide for wood pole inspection and management. POLUX and its analysis software K-Store offer a fast, much more reliable and more cost-effective means of testing and managing a utility’s wood pole fleet.

POLUX is a hand-held portable instrument to test the condition and strength of wood poles, non destructively, in the field. It gives an instantaneous indication (red or green light) whether the pole is safe to climb, and an estimate of the expected remaining service life. It succeeds where other attempts have failed, by measuring both compressive strength and moisture, and correlating the two variables and comparing against parameters developed from measurements under controlled conditions. A handheld computer provides visual data display. (Future plans may include incorporation of GPS.)

POLUX was developed and commercialized in Europe by a Swiss company with funding from Electricite de France. EdF has accredited it for safety and has adopted it as their only acceptable method for wood pole testing. More than 100 instruments are in use in Europe, validating its performance and providing a base of experience. The instrument is manufactured to ISO 9002 standards and the testing procedure has been certified ISO 9001 in Europe.

Pole + Management Inc., in Montreal, is the exclusive licensee in North America for the POLUX technology. The company has done exhaustive testing and calibration (i.e. for the different wood species used in the Americas), and is now beginning to market it. They made their first major public showing at the April IEEE T&D show in New Orleans.

In 1998, Pole + began inspections for a dozen small utilities in Ontario, and also performed wood pole inspections for Ontario Hydro on some of their transmission lines. Hydro-Quebec did tests at their research center IREQ which compared POLUX, sonic, drill, x-ray, and other methods of pole inspection– the POLUX measurements consistently had the highest correlation ( r > 0.85) with the actual residual breaking strength of the pole. (reports available). Other utilities who have also evaluated different methods of measuring pole strength, concluding that sonic testers do not correlate with the pole breaking strength and that a valid instrument must have a correlation of at least r > 0.7.

The strength of a pole is proportional to fiber stress and to the cube of the circumference of the pole. Almost 80% to 90% of the bending capacity in a typical utility pole is developed in the outer 2 to 3 inches of the shell. The center portion of a pole adds very little to its bending strength, so voids or decay there are far less important.

Many US utilities rely on core samples (to detect the presence of decay) and treatment programs, but this can give a false sense of security, and be less cost effective in the long run. (Treating a pole that doesn’t need it can sometimes actually reduce its strength and remaining life!) In some companies, work practices and union rules may hinder adoption of this different approach, but the company (and Europe!) is convinced that it is the better way to go, for many reasons.

Benefits from Reliable Non-Destructive Wood Pole Inspection
– Decisions based on reliable, repeatable, objective data, independent
of operator interpretation
– Capability to decide when to replace, retreat or strengthen poles
– Capability to plan purchasing, storage, and maintenance needs
– Long term trend patterns will provide a sound basis for new, cost-effective
and ecologically sound strategies for pole selection, placement, re-inspection
and maintenance
– Reduce capital and maintenance cost
– Improve system reliability and customer satisfaction.

The company will send on request a CD-ROM that provides the complete story. Also, their website gives a good introduction to the technology and concepts.
http://www.poleplus.com

They are looking for U.S. utilities to participate in small pilot demo programs, where the company will test several hundred poles (at $10 each).

Contact: Edward Ezer, Pole+ Management, Inc. (Montreal, Quebec)
514-947-0122 eezer@poleplus.com

(UFTO has been following these developments since mid 1996.)

Emerging Transmission Market Segments (IEEE Article)

/0 Comments/in , /by

The article cited below is from the January issue of Computer Applic in Power, and for non-subscribers interested in T&D issues, it happens to be available in its entirety on the IEEE website: http://teaser.ieee.org/pubs/mags/9905/rahimi.html

I thought you might find it useful as an overview of the various ways transmission systems are being organized around the world.

>>>>>>>>>>>>>>>>>>>>>>>>>>
Who’s coming to the IEEE PICA Meeting in Santa Clara this month (May 17-20)??

Let me know, and maybe we can get together, or at least say hello at the conference.
Complete details available at: http://www.pica99.org
>>>>>>>>>>>>>>>>>>>>>>>>>>
Remember QuickStab? (UFTO Note March 22) Dr. Savalescu will be at PICA, and would be pleased to offer a private demonstration. Give him a call!
>>>>>>>>>>>>>>>>>>>>>>>>>>
(I just joined IEEE, and am beginning to appreciate the wealth of information it provides to the power industry.)
>>>>>>>>>>>>>>>>>>>>>>>>>>
IEEE Computer Applications in Power January, 1999 Volume 12 Number 1 (ISSN 0895-0156)

Meet the Emerging Transmission Market Segments
Farrokh A. Rahimi & Ali Vojdani

Around the globe, the electric industry is undergoing sweeping restructuring. The trend started in the 1980s in the U.K. and some Latin American countries, and has gained momentum in the 1990s. The main motivation and driving forces for restructuring of the electric industry in different countries are not necessarily the same. In some countries, such as the U.K. and the Latin American countries, privatization of the electric industry has provided a means of attracting funds from the private sector to relieve the burden of heavy government subsidies. In the countries formerly under centralized control (central and eastern Europe), the process follows the general trend away from centralized government control and towards increased privatization and decentralization. It also provides a vehicle to attract foreign capital needed in these countries. In the United States and several other countries where the electric industry has for the most part been owned by the private sector, the trend is toward increased competition and reduced regulation.

This article presents an overview of the evolving structural models and the main structural components of the emerging deregulated electricity industry. An analysis of the central structural components, namely the independent system operator (ISO) and the power exchange (PX), is provided and used as a basis for structural classification with a view to the supporting computer application needs.

QuickStab: Calculates Maximum Transmission Load and Stability Margin

/0 Comments/in , /by

(Two years ago, the developer of this program was referred to UFTO by DOE, and an UFTO Note was done at that time. Since then, the need has become even greater; there have been improvements to the code; and it has been implemented by a major utility.)

———
With deregulation, privatization and open access transmission, energy transactions across large electrical distances become commonplace, and can cause major wheeling power flows which, in turn may bring the networks near their limits of stability and loadability.

However, power systems cannot be operated safely near the state of maximum loadability. A much lower load level needs to be defined such that all thermal, voltage and stability constraints are met. NERC calls it the Total Transmission Capability (TTC) and recommends to further reduce it by a Transmission Reliability Margin (TRM) to account for uncertainties. This value must be further adjusted by the Capacity Benefit Margin (CBM) to finally determine the system loading that guarantees full operating security.

The safe operating limit, however, is highly dependent upon topology, voltages, number and location of generators, and other system conditions. For dependable on-line decision making, this limit must be reassessed in real-time for every single change of the operating state.

Critical states occur at or close to the TTC. This limit is not constant. It depends on the generation, customer demand and transmission network conditions, and must be computed from the real-time conditions of the transmission network. Such a capability is needed both in real-time and for postulated conditions, but detailed stability methods are time consuming and require data that may not be readily available.

QuickStabTM answers this need. It identifies both the point of maximum power transfer and the distance to it without computing load-flows. In other words, it predicts the maximum loadability from any operating state, even if far from the limit conditions. This feature is one of the most particular aspects of the short-circuit currents nodal analysis and cannot be found in other algorithms.

Starting from a power-flow or state estimator base case, it computes the system’s MW loading limit such that voltage collapse and steady-state instability do not occur. Then it shows which units and tie-line injections are most likely to cause instability; provides information that can help develop a remedial action strategy; and identifies the P-V points of successively degraded states towards instability. Quickstab also determines the system MW loading for a user-defined security margin.

Results are displayed in a unique, easy-to-understand graphical format. The computations are extremely fast. For example, the solution of a 300 bus case on an inexpensive PC takes just 0.44 sec. Most recently, the QuickStabTM computational modules were enhanced and recompiled with Microsoft C/C++ version 6.0 in a Windows NT 32 bit native environment. The program also runs under Windows 95/98. It is Y2K compliant.

QuickStab’s solution technique is based on the short-circuit currents nodal analysis method, which was perfected in Europe in 1961 and became a “classic” in the voltage-stability circles in 1980. Two studies sponsored by EPRI and Southern Company Services (Southern) in 1990-1993 demonstrated the speed and validity of the approach.

It is now field-proven. In 1998, QuickStab was adopted by Companhia Energetica de Sao Paulo CESP, in Brazil, and by Oficina de Operacion del Sistema Interconectado OPSIS, in Venezuela. CESP uses the program both off-line, on PCs under Windows 98, and in real-time on Digital Alpha processors under Digital Unix. OPSIS uses QuickStab for real-time only. These two EMS implementations of QuickStab were provided by ABB-Bailey Network Management as part of its RANGER baseline.

QuickStab offers significant benefits. It can help increase revenues from wheeling power while meeting higher MW demand and reliability requirements. It can be used on-line, embedded in or as an add-on to an existing EMS. And with its modular design and ANSI C compliant code implementation it can be easily integrated with third-party load-flow, contingency analysis and security assessment programs.
QuickStab is available now to utilities, consultants and universities, under a range of license options.

For additional information, or to make arrangements for a presentation, contact:
Dr. Savu Savulescu
SCS Computer Consulting, Fresh Meadows NY
718-264-7563, savu.scs@worldnet.att.net