July/August 2007 Finepoint Factory Day i... · 3 6 Making Everyone Accountable for Theft 8 Using Geosynthetics for Oil Containment 14 High Voltage Proof Design Testing 13 lTurning

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July/August 2007 Volume 19, No. 6


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July/August 2007 Volume 19, No. 6

FinepointFactory Day

Pennsylvania Breaker’s high voltage test lab is oneof the host sites for Finepoint’s “Factory Day” tour.

The Circuit Breaker Test &Maintenance Training Conferenceis slated for October.

See page 28 for theofficial floor plan.

Finepoint’s14th Annual

Circuit Breaker

Test & Maintenance

Training Conference

October 1-5, 2007Pittsburgh, Pennsylvania

www.circuitbreakerconference.com

ET July August 7/18/07 9:37 AM Page 1


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6 Making Everyone Accountable for Theft

8 Using Geosynthetics for Oil Containment

14 High Voltage Proof Design Testing

13 lTurning Off-the-Grid Customers into Grid Contributors

32 lPower Transmission Capacity Upgrade of Overhead Lines - Part I

18 reYou Said It

20 Ethernet in Substation Automation Applications - Part II

24 Cyber Security for Effective Demand Side Management and AMI Projects

39 AMRA Applauds NARUC Resolution Eliminating Regulatory Barriers to AMI

27 Are You Working Safely? Training Forums Ensure You Will

28, 29 2007 Finepoint Circuit Breaker Test & Maintenance Conference

38 Examining Advanced Transmission Technologies - Part I

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in this issueEDITORIAL

TESTING

TRAINING

SUBSTATION AUTOMATION

METERING

OVERHEAD TRANSMISSION

CONFERENCES

READER RESPONSE

TRANSMISSION TECHNOLOGIES

ADVERTISERS INDEX

Electricity Today Magazine is published 9 times peryear by The Electricity Forum [a division of The HurstCommunications Group Inc.], the conference manage-ment and publishing company for North America’s elec-tric power and engineering industry. Distribution: free of charge to North American electri-cal industry personnel who fall within our BPA requestcirculation parameters. Paid subscriptions are availableto all others. Subscription Enquiries: all requests for subscriptionsor changes to free subscriptions (i.e. address changes)must be made in writing to:

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PRODUCTS AND SERVICES SHOWCASE


Electricity Today4

editorial board

BRUCE CAMPBELL

DAVID O’BRIEN

CHARLIE MACALUSO

SCOTT ROUSE

BRUCE CAMPBELL, LL.B., Independent Electricity System Operator (IESO)Mr. Campbell holds the position of Vice-President, Corporate

Relations & Market Development. In that capacity he is responsible for theevolution of the IESO-administered markets; regulatory affairs; externalrelations and communications; and stakeholder engagement. He hasextensive background within the electricity industry, having acted as legalcounsel in planning, facility approval and rate proceedings throughout his26-year career in private practice. He joined the IESO in June 2000 and isa member of the Executive Committee of the Northeast Power CoordinatingCouncil. He has contributed as a member of several Boards, and was Vice-Chair of the Interim Waste Authority Ltd. He is a graduate of the Universityof Waterloo and Osgoode Hall Law School.

DAVID O’BRIEN, President and Chief Executive Officer, Toronto HydroDavid O'Brien is the President and Chief Executive Officer of TorontoHydro Corporation. In 2005, Mr. O'Brien was the recipient of theOntario Energy Association (OEA) Leader of the Year Award, establish-ing him as one of the most influential leaders in the Ontario electricityindustry. Mr. O'Brien is the Chair of the OEA, a Board Member of theEDA and a Board Member of OMERS.

CHARLIE MACALUSO, Electricity Distributor’s AssociationMr. Macaluso has more than 20 years experience in the electricity

industry. As the CEO of the EDA, Mr. Macaluso spearheaded the reformof the EDA to meet the emerging competitive electricity marketplace, andpositioned the EDA as the voice of Ontario’s local electricity distributors,the publicly and privately owned companies that safely and reliably deliverelectricity to over four million Ontario homes, businesses, and public institutions.

SCOTT ROUSE, Managing Partner, Energy @ WorkScott Rouse is a strong advocate for proactive energy solutions. He

has achieved North American recognition for developing an energy effi-ciency program that won Canadian and US EPA Climate ProtectionAwards through practical and proven solutions. As a published author,Scott has been called to be a keynote speaker across the continent fornumerous organizations including the ACEEE, IEEE, EPRI, and CombustionCanada. Scott is a founding chair of Canada’s Energy Manager networkand is a professional engineer, holds an M.B.A. and is also a CertifiedEnergy Manager.

DAVID W. MONCUR, P.ENG., David Moncur EngineeringDavid W. Moncur has 29 years of electrical maintenance experience

ranging from high voltage installations to CNC computer applications, andhas conducted an analysis of more than 60,000 various electrical failuresinvolving all types and manner of equipment. Mr. Moncur has chaired aCanadian Standards Association committee and the EASA OntarioChapter CSA Liaison Committee, and is a Past President of the WindsorConstruction Association.

JOHN McDONALD, IEEE PresidentMr. McDonald, P.E., is Senior Principal Consultant and Director of

Automation, Reliability and Asset Management for KEMA, Inc. He isPresident-Elect of the IEEE Power Engineering Society (PES), ImmediatePast Chair of the IEEE PES Substations Committee, and an IEEE Fellow.

DAVID W. MONCUR

JOHN McDONALD



Electricity Today6

Copper theft hasincreased 1,150 per centfrom 2005 to 2006.

That’s one thou-sand, one hundred andfifty per cent.

This sort of mind-boggling explosion ofcrime in any other sec-tor of the communitywould have headlinesscreaming from onecoast to the other, andpeople demandingimmediate action fromthe police.

But hey, it’s onlythe utility; so who cares,right?

Aside from thecomplete foolhardinessof stealing copper fromactive transmission anddistribution networks(those who do it wrongonce never do it again),these acts of theft andvandalism costOntario’s Hydro One anestimated $1 million ayear.

Copper theft hasbecome the fastestgrowing form of crimein Ontario, and the cop-per wire used in powerlines is proving to be anattractive target forthieves.

To help combat thisrunaway crimewave,Hydro One is contribut-ing $10,000 to Crime Stoppers to helpraise awareness among the public.

Crime Stoppers is an organizationthat offers financial rewards leading tothe capture and successful prosecution ofcriminals.

“This is becoming a very seriousproblem,” says Chris Price, Hydro One’sDirector of Security. “These thefts threat-

en the safety of the general public andHydro One staff and could negativelyimpact electricity reliability. We expectour partnership with Crime Stoppers, andworking closely with local law enforce-ment will help reduce this criminal activ-ity.”

Price explained that the benefits ofpartnering with Crime Stoppers include

the option of anonymity when reportingincidents, and rewards for providinginformation leading to arrests. “Webelieve that the partnership will increaseidentification of metal thieves, and thosepaying for stolen metal.” He added thatHydro One continues to undertake inves-tigations of copper/metal thefts, and hasinvested in improved security systems.

Pat Gillie, President of the OntarioAssociation of Crime Stoppers empha-sized that for citizens who fear reprisal orare reluctant to get involved, CrimeStoppers is an option for reporting infor-mation about this dangerous theft.“Calling 1-800-222-TIPS is all it takes,”she says.

The mere fact that Hydro One hashad to take this drastic step to curb thetheft of copper is indicative of the publicattitude toward major utilities.

Many feel that they are not stealing.Many are upset with the increase in theirelectricity bills, and feel justified in steal-ing from a large corporation.

“They can afford it,” seems to be theexcuse for many caught red-handed.

The owner and operator of Ontario’s29,000 kilometres of high-voltage trans-mission network and 122,000 kilometrelow-voltage distribution system, HydroOne is responsible for thousands of tonsof copper stretching from heavily urban-ized centers like Toronto to vast wilder-nesses like that of northern Ontario.

Not unique in having to deal with thetheft of copper, Hydro One is unique inchoosing to use Crime Stoppers as anextra weapon in the ongoing battleagainst theft and vandalism.

With this crime now costing HydroOne $1 million a year, it would be inter-esting to see if there was an increasedpublic vigilance if this cost was itemized(like the debt retirement) on customers’electricity bills.

It may be only a few extra cents percustomer, but the message would be clear- there is a problem, and it is up to every-one to help put a stop to it.

[email protected]

EDITORIAL

MAKING EVERYONE ACCOUNTABLEFOR THEFT

Don Horne



Electricity Today8

Oil is oil, whether consumed orused as fuel. So says the USEPA. Alloils have the same effect on the envi-ronment when allowed to enter thesub-soil or, worse, the water table.Anything that behaves like oil float-ing on water is considered to be oil.

No site wants to have an oilspill, into the waterway, or ground-water, especially in a residentialarea. Publicity following a spill willhurt the company’s image, not tomention the fines and remediationcosts associated with a spill.

Geosynthetics consist of the fol-lowing polymeric materials used inenvironmental, geotechnical, trans-portation and hydraulic engineeringapplications:

• Geotextiles – porous textiles;• Geomembranes – imperme-

able liners;• Geogrids – reinforcement grids;• Geonets – drainage nets;• Geosynthetic Clay Liners – rolls of

bentonite in/on geosynthetics;• Geocomposites – various assemblages

of geosynthetic and, sometimes, soil materi-als.

Geosynthetics, being a man-made syn-thetic material, can be modified, or combinedwith various other geosynthetic materials, togive the final results required when buildingin geotechnical applications.

There is a broad range of geosyntheticmaterials available, with more coming onstream each year to solve problems in civilengineering.

Some products which are quite commonand have been in use for many years areproducts such as geotextiles. Geotextiles caneither be a woven product for lateral flow ofliquids or a fibrous product (nonwovens) forfiltering and separation of soils. Geotextilescan weigh from as little as 100 g/m - to 1000g/m - depending on the application.Geotextiles were first developed in commercial use about 35years ago for use on railroad beds for stabilization. Today theyare commonly used in such areas as residential gardens, actingas weed control around plants.

A geomembrane is used in containment applications. It is

an impervious sheet, typically made of plastic. The plastic willbe polypropylene; HDPE; LLPE; PVC, among other types ofresins. These sheets of plastic will range in thickness from 0.25

TESTING

USING GEOSYNTHETICS FOROIL CONTAINMENT

By Scott Lucas, President of Albarrie

Continued on Page 10



mm to 3.5 mm. Geomembranes are manufac-tured by machinery very similar to that whichmanufactures a garbage bag, however thewidths can be up to 15 meters. Geomembraneswill block the mitigation of fluids.

Another product is a Geosynthetic ClayLiner. This product encapsulates sodium ben-tonite between two porous sheets of geotex-tiles. The sheet on the top, the bentonite andthe sheet on the bottom are bonded togetherusing a special machine that will take fibersfrom one sheet of geotextiles and interlock ittogether with another sheet. GeosyntheticClay Liners, when saturated with water andunder a confining stress, will, like thegeomembrane, become impervious. This 6-mm thick composite will have the same per-meability characteristics as 1 meter of com-pacted clay.

All of these geosynthetics working in conjunction witheach other have been used for many years in containmentapplications, such as municipal solid waste landfills to preventthe seepage of leachates from the waste entering into thegroundwater. The geosynthetics will also be used to cap thewaste once the cell is full, preventing precipitation from enter-ing the waste. These geosynthetics are also used for remedia-tion sites when one wants to prevent the precipitation enteringcontaminated soils and further contaminating an area downstream.

As these geosynthetics are buried wherethere is little oxygen and are not subjected toultra-violet rays, their half-life has been esti-mated to be up to 400 years.

The geomembranes and theGeosynthetic Clay Liner contain all liquidswhether they are water or hydrocarbons. Thetask was to design a system using geosyn-thetics which would allow precipitationwhether in the form of rain or snow melt topass through - and, at the same time, containhydrocarbons while not allowing them toescape.

A product known as Rubberizer, alsoknown as a co-polymer, has been on the mar-ket for a considerable period of time. The co-polymer is basically a type of hydrocarbonwhich will absorb other hydrocarbons. Theseco-polymers can be designed to absorb hydrocarbons and stillbe porous and are typically spread over the surface of the waterto absorb oil which may be floating on the surface. The co-polymer can also be designed to absorb the hydrocarbons andcongeal, becoming impermeable.

Trials with various co-polymers showed that a product thatabsorbed and congealed would prove very useful. With a prod-uct that totally sealed on full saturation of hydrocarbons anymigration of hydrocarbons from the containment area would beprevented.

Using the principal developed to manufacture

Geosynthetic Clay Liners, the sodium bentonite was removedfrom the equation. A co-polymer was then substituted betweenthe two porous geotextiles. Trials and laboratory testing wereconducted to assure the correct amount of co-polymer wasinstalled in the center of the two geotextiles. A correct amountof co-polymer is required to assure its effectiveness. By spread-ing the co-polymer mechanically in a production situation, itcan be assured that the correct amount of co-polymer is appliedto the composite as with the bentonite for the GeosyntheticClay Liner.

Hence, another Geosynthetic isborn - The Geosynthetic Oil Mat.

As with other containment sys-tems, various types of geosyntheticsare used for specific reasons. In theSorbweb Plus system to containhydrocarbons, various geosyntheticsare also used.

On the bottom of the system, TheGeosynthetic Oil Mat is placed overporous soil to allow for drainage ofthe precipitation, water from outsidesources and snow melt. TheGeosynthetic Oil Mat is only activeonce hydrocarbons come into con-tact with it.

The sidewalls around the perimeterof the system are lined with a

geomembrane which is impervious, directing the flow of anyliquids to the bottom of the system, and preventing any liquidfrom leaving the containment area through lateral movement.

Above the Geosynthetic Oil Mat is placed a number ofdrainage layers with woven geotextiles between the drainagelayers. Woven geotextiles give a lateral flow so that in the eventof an oil spill, the oil will not flow immediately down to theGeosynthetic Oil Mat allowing for dispersion of the oil andother liquids. This dispersion also gives dwell time for the co-

Electricity Today10

Oil ContainmentContinued from Page 8


As these geosyn-thetics are buriedwhere there is littleoxygen and notsubjected to ultra-violet rays theirhalf-life has beenestimated to be upto 400 years.

Testing of the system was conducted at the Kinectrics’ Laboratory in Toronto, Ontario



polymer to fully absorb any hydrocarbon that comes in contactwith it.

The system is topped with fire quenching stone which willbe the reservoir for both the oil and water in case of a catastro-phe. There are also, within the containment system, additionalhydrocarbon absorption layers.

If, by some means, the system becomes damaged due to insitu digging or other unknown reasons, the system is repairable.

A case study of the Sorbweb System proving that it workswas the successful containment of a 4,000 liter spill followingan accident at a site located along the Don River in Toronto,Ontario Canada.

In another instance, in 2005 there was a fire and cata-strophic failure of a Main Output Transformer (MOT) at anuclear generating station that resulted in an oil spill. Some oilwas ultimately discharged into a large local lake. As a result, theclient commissioned installation of a secondary oil containmentsystem to protect against damage by any potential future inci-dents.

The Sorbweb Plus oil containment system was selectedfrom several competing systems for this project. One of themajor reasons was that there would be no disruption of servicefrom the installation of the containment system.

This turnkey project was divided into phases. Each phaseinvolved three main tasks:

1. Sorbweb Plus system design and material procurement;

2. Construction, including excavation, soil disposal andSorbweb Plus installation;

3. Environmental engineering, including soil sampling andtesting.

Kinectrics acted as the general contractor for the entire pro-ject. The containment system is designed to contain 3,600,000liters of transformer oil.

Stones and soil were removed from around and behind theMOT units. Rebar with concrete sloping towards the contain-ment system areas was installed in some areas where placingSorbweb Plus would have been impractical. Additional excava-tion was performed using Gradall scraping, carried out 15 cm ata time.

Pre-cast cement blocks formed the exterior and sides of thebelow-grade dike of the system. Sand, the initial layer of theSorbweb Plus, was spread, followed by oil resistant plasticaround the entire cement perimeter and interior obstructions todirect any oil or water down through the Sorbweb Plus.Proprietary layers of the Sorbweb Plus were then installed.Finally, additional materials and fire-quenching stones com-pleted the system installation.

Sorbweb Plus solution is an effective and reliable passivesystem that provides continuous protection against oil spillsfrom transformers. It is a smart system that allows water todrain through a containment area without accumulating, whileretaining any oil that might leak from the transformer. SorbwebPlus provides the client with a cost effective, no maintenancesystem that will provide reliable secondary oil containment ofspills from transformers over a long period of time.

Electricity Today12

Oil ContainmentContinued from Page 10

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In the wilds of Northern Ontario, electricity meant the humof a diesel generator.

The small hamlets and villages that dot the landscape ofthe Canadian Shield are, for the most part, all populated byFirst Nations peoples.

Living off the grid has been- and still is - a reality for theFirst Nations’ peoples, but therealities of the modern world –primarily the need to create eco-nomic revenue while reducingharmful emissions – are becom-ing more of a fact of life for thethousands of residents ofNorthern Ontario.

Negotiations are currentlyunder way with a number of FirstNations’ peoples to create aneast-west transmission corridorfrom northern Manitoba acrossNorthern Ontario to Sudbury.Tapping Manitoba’s hydro-richgeneration reserves is part of alarger effort to strengthen theeast-west electricity intertiesacross Canada (there are concur-rent negotiations with Quebecand Newfoundland-Labrador tobuild similar transmission linksinto Ontario).

The obstacles to thisnew corridor (terrain, distance,an estimated cost of $2 billion)can be overcome (new building techniques, DC transmissionand public/private investment), but the land rights issues maybe the true sticking point.

For the aboriginal peoples, they want a level of partic-ipation and a benefit from the new transmission corridor. Yearsago when Quebec launched the massive James Bay hydroelec-tric project, the Cree people in the area established a cadre oftechnically trained residents to help build and maintain the pro-ject. For Hydro One and, by extension, the province of Ontario,the distance between the communities and small populationsize makes creating a viable local workforce of properly trainedindividuals truly daunting in a short span of time.

The question of having the First Nations’ peoples make asizeable investment in the corridor is moot, considering that thevast majority of the various peoples still rely on hunting andfishing to provide an income. The great casino cash cows that

are thriving among their fellow First Nations peoples to thesouth cannot be found here.

So that leaves a better, cleaner access to electricity forthese isolated communities – freedom from the noisy, green-house gas polluting diesel engines currently running the lights,

stoves and refrigerators in Northern Ontario.Simply string a few lines along the corridorand all is well.Except that the corridor will all too likely beDirect Current, not AC.

The sheer distance of the line necessi-tates using DC, eliminating the considerablevoltage loss and higher cost of AC transmis-sion lines.

For these small communities, it doesn’tlook likely that they will each have their ownconversion station built at their doorstepsalong the line, reaping the benefits of the hun-dreds of megawatts of power running pasttheir homes.

Any savings that will be had using DCinstead of AC would be quickly eaten up ifconversion stations are constructed for all ofthe communities within proximity of the cor-ridor. This would leave the First Nations peo-ple back where they started, except that nowthey would have a transmission line runningthrough their lands.

One option that would be attractive toboth the province’s electricity provider andthe First Nations’ groups would be the con-struction and integration of the tens of thou-sands of megawatts of wind generation avail-

able in Northern Ontario.Such wind power could supplement these communities

with not just electricity, but money from the generation theywould be putting into the grid. The staffing, maintenance andconstruction of these wind farms would also provide the FirstNations’ peoples with employment opportunities with muchgreater permanence than a one-off transmission corridor pro-ject.

Yes, the wind farm projects would be an additional cost tothe entire project; but it makes more sense to put the moneyinto more, cleaner generation on a local level than to just buildcountless conversion statements drawing power away from thegrid.

Wind doesn’t offer a stable power supply, but it does offerthe First Nations a chance to participate and grow along withthe corridor.

July / August 2007

TURNING OFF-THE-GRID CUSTOMERS INTOGRID CONTRIBUTORS

By Don Horne



Electricity Today14

In 1996, theinsulated conduc-tor industry deter-mined that DCwithstand testingof the plastic(XLPE) insula-tion systemseither in the cablefactory as a rou-tine productiontest or afterinstallation as thehigher voltageproof test wasdetrimental to thelife of the insula-tion and thereforediscontinued rec-ommending DCtesting.

M e d i u mvoltage EPRinsulating sys-tems are not sub-ject to the sameaging characteristics and, therefore, canbe DC tested as required in accordancewith the tables below.

When an insulated cable arrives onthe job site, the recipient should be ableto confidently assume it will attain thedesigned service life. This means it mustarrive free of internal discontinuities inthe dielectric such as voids or inclusions,as well as freedom from air pockets at theinterfaces between the shielding systemsand the dielectric’s surfaces. It is, howev-er, the specter of mechanical damage, orsubstandard splicing and terminating thatcould cause the engineers responsible forcontinuity of service to desire a fieldapplied proof test to establish the cable’sserviceability.

The time-honored methods of prooftesting in the field involve high potentialdirect current (DC). The advantage of theDC test is obvious. Since the DC poten-tial does not produce harmful dischargeas readily as the AC, it can be applied athigher levels without risk or injuring

good insulation. This higher potentialcan literally “sweep-out” far more localdefects. The simple series circuit path ofa local defect is more easily carbonizedor reduced in resistance by the DC leak-age current than by AC, and the lower thefault path resistance becomes, the morethe leakage current increased, thus pro-ducing a “snow balling” effect whichleads to the small visible dielectric punc-ture usually observed.

Since the DC is free of capacitivedivision, it is more effective in pickingout mechanical damage as well as inclu-sions or areas in the dielectric that havelower resistance.

Field tests should be utilized toassure freedom of electrical weakness inthe circuit caused by such things asmechanical damage, unexpected envi-ronmental factors, etc. Field tests shouldnot be used to seek out minute internaldiscontinuities in the dielectric or faultyshielding systems, all of which shouldhave been eliminated at the factory, nor

should the DC potential be excessivesuch that it would initiate punctures inotherwise good insulation.

For low voltage power and controlcables it is general practice to use a meg-ger for checking the reliability of the cir-cuit. This consists essentially of measur-ing the insulation resistance of the circuitto determine whether or not it is highenough for satisfactory operation. Forhigher voltage cables, the megger is notusually satisfactory and the use of highvoltage testing equipment is more com-mon. Even at the lower voltages, highvoltage DC tests are finding increasingfavor. The use of high voltage DC hasmany advantages over other types of test-ing procedure.

DC FIELD ACCEPTANCE TESTINGIt is general practice, and obviously

empirical, to relate the field test voltageupon installation to the final factory

TESTING

HIGH VOLTAGE PROOF DESIGN TESTING




applied DC potentials byusing a factor of 80 per-cent. The final factory-test voltages can befound in the appropriateindustry specifications.This means that prior tobeing connected to otherequipment, solid extrud-ed dielectric insulatedshielded cables rated5kV and up may be givena field acceptance test ofabout 300 volts per mil.

The actual test val-ues recommended for the field acceptance test are presented inthe table on the previous page. If other equipment is connect-ed it may limit the test voltage, and considerably lower levelsmore compatible with the complete system would be in order.

TEST LIMITATIONSThe DC leakage can be affected by external factors such

as heat, humidity, windage, and water level if unshielded andin ducts or conduits, and by internal heating if the cable undertest had recently been heavily loaded. These factors makecomparisons of periodic data obtained under different test con-ditions very difficult. If other equipment is connected into thecable circuit this makes it even more difficult. In the event hotpoured compound filled splices and terminations are involved,testing should not be performed until they have cooled to roomtemperature.

The relays in high voltage DC test equipment are usuallyset to operate between 5 and 25 milliamperes leakage. In prac-tice, the shape of the leakage curve, assuming constant volt-age, is more important than either the absolute leakage currentof a “go or no go” withstand test result.

TEST NOTESFrom the standpoint of safety as well as data interpreta-

tion, only qualified personnel should run these high voltage

tests.After the voltage has been applied and the test level

reached, the leakage current may be recorded at one minuteintervals. As long as the leakage current decreases or stayssteady after it has leveled off, the cable is considered satisfac-tory. If the leakage current starts to increase, excludingmomentary spurts due to supply-circuit disturbances, troublemay be developing and the test may be extended to see if therising trend continues. The end point is, of course, the ultimatebreakdown.

This is manifested by an abrupt increase in the magnitudeof the leakage current and a decrease in the test voltage. Itshould result in relay action to “trip” the set off the line, butthis assumes the equipment has enough power to maintain thetest voltage and supply the normal test current. Since the totalcurrent required is a function of cable capacity, condition ofdielectric, temperature, end leakage and length, the test engi-neer must be sure that “relay action” actually signifies a localfault, rather than being merely an indication that the voltagehad been applied too quickly or one of the other factors con-tributing to the total current had been the cause.

At the conclusion of each test, the discharge and ground-ing of the circuit likewise requires the attention of a qualifiedtest engineer to prevent damage to the insulation and injury topersonnel.

Electricity Today16

Design TestingContinued from Page 14

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MAINTENANCE PROOF TESTINGIt may be justifiable in the case of important

circuits to make periodic tests during the life of theinstallation to determine whether or not there hadbeen significant deterioration due to severe andperhaps unforeseen operational or environmentalconditions. The advantage of a scheduled prooftest is, of course, that it can frequently “anticipate”a future service failure, and the necessary repair orrenewal can be made without a service interrup-tion, usually during a major shutdown.

Furthermore, a DC test failure is seldomburned-out, and visual analysis may disclose thecause and permit corrective action.

As a note of caution, once a complete circuithas been connected and all exposed ends sealed, it is not desir-able when maintenance proof-testing to remove these seals, dis-connect the conductors, and it is sometimes impossible to pro-vide “ends” with adequate clearance and length of insulationsurface to permit high voltage testing even at the levels speci-fied in the following table.

Further, there is the danger of mechanically injuring thedielectric during the seal removal and end preparation. This is amajor reason why a “megger test” is often used in maintenancechecking of the numerous circuits in a power plant.

FREQUENCY OF TESTSIn the case of power plants, it is customary to schedule

desired maintenance proof tests to coincide with planned majorshutdowns. It is not necessary or justifiable to check every cir-cuit each year. The above schedule is suggested as a guide.

Courtesy of the Okonite Company. You can find this article andmany more like it in our 2007 Wire and Cable handbook. Checkout our website www.electricityforum.com for information onhow to purchase this handbook or others like it.

17July/August 2007


Electricity Today18

Graham Austin, who was an Energy/EnvironmentalManager with Alberta Distillers Ltd. in Calgary Alberta writes,“I retired on May 31st so your magazine will no longer reachme. Thank you for your past issues - they were most informa-tive and helpful.”

Ron Mazur, Manager of the System PlanningDepartment with Manitoba Hydro in Winnipeg, Manitoba says,“I find the magazine articles very informative and practical.”

James McLaren, Manager of Bear Creek Consulting inCharlton, Ontario writes, “I find both Electricity Forum andThe (Electrical) Source interesting and an asset when lookingfor information and equipment.”

Tim Ross, a Facilities Specialist with Nav Canada inEdmonton, Alberta says, “Very interesting articles.”

Bill Kay, an Electrical/Int. Foreman with CVRD IncoLtd. in Thompson, Manitoba writes, “I look forward to andenjoy this magazine for its material information and the main-tenance articles.”

Berni Fuchs, CEO of Chalet Enterprises Inc. inEdmonton, Alberta says, “Absolutely great resource. Great arti-cles. Keep up the good work. Really appreciated.”

Michael Chocho, a Senior Buyer with ATCO Electricin Edmonton, Alberta writes, “I have found your publication tobe very informative, especially the articles. Keep up the goodwork.”

Maurice Renaud, an electrician with the BrockvilleMental Health Centre in Frankville, Ontario says, “I enjoyreceiving and reading your magazine.”

Sumantray Patel, an Engineering Manager withEnergy Systems & Applications in Brampton, Ontario writes,“A very useful magazine with a lot of technical information.”

Ove Albinsson, a Technologist with BC Hydro inBurnaby, British Columbia says, “Keep up the good work!”

Cole Tucker, a Utilities Technician with the City ofVernon in Vernon, BC writes, “Good magazine. I like the num-ber of areas you cover and that it is not focused on only one ortwo areas.”

Kevin Trottier, an Electrical Supervisor with Canfor inHouston, BC says, “I would just like to comment on how muchI enjoy your Canadian Electrical Code sections. It really helpsin keeping me up to date and clarifies a lot with the attachedformulas and explanations. I usually race to that section andthen read the rest of the magazine. Thanks for a good read.”

Roy Shields, an Electrical Supervisor with Canfor inPrince George, BC writes, “It is a good read for our electricalroom. Thanks.”

Leslie Field, a Senior Product Engineer with GeneralElectric Co. in Anasco, Puerto Rico says, “I would like to seemore articles on Protective Relays, especially transformer anddistance protective relays.”

Lynn Wong, an Electrical Discipline Manager withSNC-Lavalin Inc. in Edmonton, Albera writes, “Excellent mag-azine; informative.”

Scott Morris, a Technical Supervisor with Hydro Onein Hornby, Ontario says, “I enjoy your magazine and find many

READER RESPONSE

YOU SAID IT


topics applicable to my job. Thanks.”

Greg Anderson, and Asset Manager Lines Stationswith Curchill Falls Labrador Corp. in Churchill Falls,Newfoundland-Labrador writes, “Good work in supplying meinformation.”

Russell Power, and Engineering Planner with Serco inHappy Valley-Goose Bay, Newfoundland-Labrador says,“Your publication has provided the company with valuableinformation and reference material in the past. Your magazineis passed down to the installers and maintenance people; theylook forward to your magazines.”

Gordon Reid, a Cableman with BC Hydro in Victoria,British Columbia writes, “I have greatly appreciated the inputfrom other technical professionals and have found their judge-ments and arguments to be advantageous in justifying variouspurchases of equipment and software. I also like the emphasisplaced on safe work practices and PPE (personal protectiveequipment). Thank you.”

Avtar Bining, a Program Manager with CaliforniaEnergy Commission in Sacramento, California says, “Goodmagazine!”

John Quartermain, an Operations Supervisor withNew Brunswick Power Corp. in St. Stephen, New Brunswickwrites, “I enjoy your magazine and so do the guys in the crewroom. Keep up the good work.”

Dan Ward, a Principal Engineer with DominionVirginia Power in Richmond, Virginia says, “Keep up the greatwork. Outstanding publication!”

Alfie Yip, Regional Electrical Engineer withTransport Canada, Ontario Region in North York, Ontariowrites, “You are publishing a very fine technical magazine. Itry to read all the articles and study all the advertisements. Ineed to read your magazine in order to keep up to date andabreast of new technology related to the electrical trade andprofession. Keep up the good work.”

Philip Wood, Practices and Procedures Engineer withthe Toronto Transit Commission in Toronto, Ontario says,“Electricity Today is a good reference to me. Every issue con-tains a lot of useful and practical information that is related tomy work.”

Romulus Munteanu, a Manufacturing EngineeringManager with W.C. Wood Company Ltd. in Guelph, Ontariowrites, “I consider your magazine one of the best from all avail-able technical publications.”

Melvin Liwag, Operations Manger with the OrlandoUtilities Commission in Orlando, Florida says, “Looking for-ward to learning more about cutting edge technologies fromyour publication.”

Paul Krupicz, Engineering Manager with TiltranServices in Tillsonburg, Ontario writes, “We have enjoyed themagazine and the training sessions put on by ElectricityForum.”

Theodore Gherian, a Maintenance Engineer withFirstEnergy Corp. in Akron, Ohio says, “I love this magazine!”

Edward Fatherly, a Senior Electrician with the USArmy Corps of Engineers in Russellville, Arkansas writes,“Good magazine.”

Paul Duong, an Electrical Technologist with EPCORin Edmonton, Alberta states that Electricity Today is “A verygood and educational magazine.”

Dan Ward, a Principal Engineer with DominionVirginia Power in Richmond, Virginia writes, “Keep up thegreat work. Outstanding publication!”

Falguni Shah, a Distribution Engineer with OshawaPUC Networks Inc. in Oshawa, Ontario says, “This magazineis an excellent source of information.”

Ken Lucoe, an Electrical Foreman of Rides atCanada’s Wonderland in Vaughan, Ontario says, “Great maga-zine.”

Peter B. Mahnke, who is involved with ElectricalMaintenance with Karmax Heavy Stamping in Milton, Ontariosays, “Good magazine; I like the number of areas you cover andthat (the magazine) is not focused on only one or two areas.”

If you wish to pass along your comments on the magazine toour editor, please email them to:

[email protected]

19July / August 2007


Electricity Today20

RING ARCHITECTUREA typical ring architecture is shown

in Figure 4a. It is very similar to theCascading architecture except that theloop is closed from Switch N back toSwitch 1. This provides some level ofredundancy if any of the ring connectionsshould fail.

Normally, Ethernet Switches don’tlike “loops” since messages would circu-late indefinitely in a loop and eventuallyeat up all of the available bandwidth.

However, ‘managed’ switches (i.e.those with a management processorinside) take into consideration the poten-tial for loops and implement an algorithmcalled the Spanning Tree Protocol whichis defined in the IEEE 802.1D standard.

Spanning Tree allows switches todetect loops and internally block mes-sages from circulating in the loop. As aresult, managed switches with SpanningTree actually logically break the ring byblocking internally. This results in theequivalent of a cascading architecturewith the advantage that if one of the linksshould break, the managed switches inthe network will reconfigure themselvesto span out via two paths.

Consider the following example:- Switches 1 to N are physically con-

nected in a ring as shown in Figure 4 andall are managed switches supporting theIEEE 802.1D Spanning Tree protocol.

- Typically, network traffic will flowin accordance with Path 1 as shown inFigure 4. Switch N will block messageframes as they come full circle therebylogically preventing a message loop.

- Now, assume a physical break inthe Ring occurs, let’s say betweenSwitches 3 and 4.

- The switches on the network willnow reconfigure themselves via theSpanning Tree Protocol to utilize twopaths: Path 1 and Path 2 as shown inFigure 4 thereby maintaining communi-cations with all the switches. If the net-work had been a simple cascading archi-

SUBSTATION AUTOMATION

ETHERNET IN SUBSTATION AUTOMATIONAPPLICATIONS - PART II

By Marzio P. Pozzuoli, RuggedCom inc. - Industrial Strength Networks

Figure 4a: Ring Network Architecture

Figure 4b: Star Network ArchitectureContinued on Page 22



Electricity Today22

tecture, the physical break betweenswitches 3 and 4 would have resulted intwo isolated network segments.

While Spanning Tree Protocol(IEEE 802.1D) is useful and a must forRing architectures or in resolving inad-vertent message loops, it has one disad-vantage when it comes to real-time con-trol.

Time!It simply takes too long; anywhere

from tens of seconds to minutes depend-ing on the size of the network. In order toaddress this shortcoming, the IEEEdeveloped Rapid Spanning Tree Protocol(IEEE 802.1w) that allows for sub-sec-ond reconfiguration of the network.

Advantages:- Rings offer redundancy in the form

of immunity to physical breaks in thenetwork.

- IEEE 802.1w Rapid Spanning TreeProtocol allows sub-second networkreconfiguration.

- Cost effective cabling/wiringallowed. Similar to Cascaded architec-ture.

Disadvantages:- Latency – worst case delays across

the cascading backbone have to be con-sidered if the application is very timesensitive (similar to Cascading)

- All switches should be ManagedSwitches. This is not necessarily a disad-vantage per se but simply an added com-plexity. Although, the advantages ofManaged Switches often far outweighthe added complexity.

STAR ARCHITECTUREA typical Star architecture is shown

in Figure 4. Switch N is referred to asthe‘backbone’ switch since all of theother switches uplink to it in order toform a star configuration.

This type of configuration offers theleast amount of latency (i.e. delay) sinceit can be seen that communicationbetween IEDs connected to any twoswitches, say Switch 1 and N-1, onlyrequires the message frames to make two‘hops’ (i.e. from Switch 1 to Switch Nand then from Switch N to Switch N-1.

Advantages:- Lowest Latency - allows for lowest

number of ‘hops’ between any two

switches connected to the backboneswitch N.

Disadvantages:- No Redundancy – if the backbone

switch fails, all switches are isolated or ifone of the uplink connections fails, thenall IEDs connected to that switch are lost.

FAULT TOLERANT HYBRID STAR-RINGARCHITECTURE

A hybrid fault tolerant architecture,combining star and ring architectures isshown in Figure 5. This architecture canwithstand anyone of the fault typesshown in Figure 6 and not lose commu-nications between any of the IEDs on thenetwork.

Figure 5: Fault Tolerant Hybrid Network

Figure 6: Fault Types Handled

Substation AutomationContinued from Page 20


23June 2007

FAULT TOLERANTARCHITECTURE FOR IEDS

WITH DUAL ETHERNETPORTS

A fault tolerant archi-tecture is shown in Figure7 when IEDs with dualEthernet ports are used.This architecture providesa high level of availability(i.e. uptime) and isimmune to numeroustypes of faults as shown inFigure 8.

CONCLUSIONS1. Ethernet switches

used in substationautomation applicationsshould comply witheither:

- IEC 61850-3 or- IEEE P1613standards for EMI

immunity and environ-mental requirements toensure reliable operationof networking equipmentin substation environ-ments.

2. For applicationswhere the Ethernet net-work will be involved incritical protection func-tions the Ethernet switch-es should comply with theClass 2 device definitiongiven in IEEE P1613 (i.e.error free communica-tions during the applica-tion EMI immunity typetests)

3. Managed Ethernetswitches with advancedLayer 2 and Layer 3 fea-tures such as:

- IEEE 802.3 Full-Duplex operation (no col-lisions)

- IEEE 802.1pPriority Queuing

- IEEE 802.1QVLAN

- IEEE 802.1w RapidSpanning Tree

- IGMP Snooping /Multicast Filtering should be used toensure real-time deterministic perfor-mance.

4. A variety of flexible networkarchitectures offering different levels ofperformance, cost and redundancy are

achievable using managed Ethernetswitches.

Marzio Pozzuoli is the founder and pres-ident of RuggedCom Inc., which designsand manufactures industrially hardened

networking and communications equip-ment for harsh environments. Prior tofounding RuggedCom, Mr. Pozzuolideveloped advanced numerical protec-tive relaying systems and substationautomation technology.

Figure 7

Figure 8


Electricity Today24

The electric power industry is devel-oping new operating methods in responseto the challenging environment it faces:

• The electric grid is under pressure,according to the North American ElectricReliability Council (NERC), whichstates that over the next 10 years whilethe demand for electricity is expected torise by 19% in the United States and 13%in Canada, confirmed power capacitywill increase by only 6% in the U.S. and9% in Canada. Furthermore, total trans-mission miles are projected to increaseby less than 7% in the U.S. and by only3.5% in Canada.

• Reflecting their environmental andclimate change concerns, today’s con-sumers are becoming interested in chang-ing their power consumption behaviour,particularly if financial incentives areavailable.

• In some jurisdictions, distributionoperators must respond to government-mandated deployment of new technolo-gies.

Consequently, numerous operatorsare turning to Demand Side Management(DSM) and Advanced MeteringInfrastructure (AMI) as a new approachthat can deliver great benefits to poweroperators and to their customers.

Demand Side Management allowsan operator to better manage the capacityand reliability of its network through theability to reduce power demands duringcritical peak periods. This could greatlyhelp the industry to continue to offer ser-vice reliability during the next 10 yearsand deal with the power generation andtransmission capacity gap identified byNERC. Consequently, the adoption ofDSM could allow power generation andtransmission operators to delay the con-struction of additional facilities. DSM isalso an additional tool for distributors todeliver excellent service while ensuringthat costs are kept under control.

From the consumer’s perspective,Distribution Side Management empow-

ers distributors’ customers to proactivelymanage their power consumption and tomanage their costs. Interruptible loadtariffs, time-of-use rates, and real-timepricing deliver the financial incentive forcompliance. The assurance of greaterservice reliability during peak periodsalso benefits consumers.

As part of their Demand SideManagement strategy, a large number ofNorth American distribution operatorsare working onAdvanced MeteringInfrastructure (AMI)projects. In somejurisdictions such asthe province ofOntario, operatorsare responding togovernment-mandated goals for smartmeter deployment.

The creation of a fully digital, 2-waycommunication environment betweenoperators and their customers createsseveral opportunities in addition to influ-encing demand and better controllingnetwork load. It allows operators todetect tampering/theft, to connect/dis-connect customers based on grid events,and to collect data that will allow distrib-utors to optimize their network.However, this new level of interactionwith customers can result in distributionoperators being vulnerable to attacks bymalicious computer hackers and cyberterrorists who want to illegally accessoperators’ resources. The motivation forthese attacks can range from neighboursspying on one another, to attempts atstealing service, and to efforts to destabi-lize the grid or cause a blackout.

It has been recognized that power &energy organizations are among the top 3industries to be security targets. Theexistence of cyber vulnerabilities in theelectric system has been confirmed bynumerous organizations, including theU.S. Department of Homeland Security,the US-Canada Power System Outage

Task Force, the U.S. Department ofEnergy, and the Canadian EnergyInfrastructure Protection Division.

AMI projects are also beingdeployed over a variety of network typesincluding wireless technologies such asZigBee, WiFi, and cellular. As recentlyexplained by a U.S. Justice DepartmentInformation Technology SecuritySpecialist, each of these wireless com-munication environments comprisesinherent cyber security challenges.

To counter those vulnerabilities andensure the success of their AMI project,distribution operators should thereforeput in place a comprehensive cyber secu-rity program. This program should be anintegral part of the planning and designphases of the AMI project to ensure thatservice reliability and information priva-cy are part of the underpinnings of theAMI deployment. Operators mustensure that cyber security risks are wellidentified and that appropriate measuresare put in place to address those risks.Following is the outline of an effectivecyber security approach for AdvancedMetering Infrastructure projects.

CYBER SECURITY GUIDELINES The distribution operator’s efforts to

develop a cyber security program shouldbe guided by the North AmericanElectric Reliability Council’s standards(NERC CIP 002-009), by cyber securitybest practices, as well as by the directivesissued by the U.S. Department of Energy,the U.S. Department of HomelandSecurity, and the Canadian EnergyInfrastructure Protection Division. Inaddition, the need to adequately protectcomputer systems is reinforced by theobligation for business managers to com-ply with current legislation aimed at pro-tecting information privacy as well asshareholder value. Legislation such asSarbanes-Oxley (SOX), PIPEDA, andBill C198 penalizes corporations andbusiness managers who do not have doc-

METERING

CYBER SECURITY FOR EFFECTIVE DEMAND SIDEMANAGEMENT AND AMI PROJECTS

By Peter Vickery, Executive Vice-President, Sales & Business Development, N-Dimension Solutions Inc.


umented Cyber Security processes andprocedures.

As specified by NERC, the estab-lishment of a strong cyber security pro-gram should start with a vulnerabilityassessment so that potential problemareas can be identified. The first step inthis process is to conduct a Threat RiskAssessment (TRA) on the operationalsystems to which the AMI infrastruc-ture is being added. From this process,the operator determines the prioritiza-tion and the focal areas for protection.After the TRA, the vulnerability assess-ment can be expanded to include: anarchitecture review; an assessment ofsecurity devices, network devices,servers and workstations; a cyber secu-rity policy review; and a site audit,including a physical security audit. Theassessment can also be expanded fur-ther to include the overall cyber securi-ty of an operator, including its informa-tion systems, to ensure that overall pro-ductivity is protected from cyberattacks.

CYBER SECURITY BEST PRACTICESIt is recommended that, when formulating their Cyber

Security program, distribution operators consider the best prac-tices that have evolved in this area. The best practices method-ology takes a holistic approach to security, and includes 3 dis-tinct elements: physical security, human factors, and technolo-gy security. For purposes of this article, we will concentrate onthe security of the technology element.

Through the evolution of the variety and of the severity ofattacks to which technology resources have been exposed overthe past few years, managers have put in place a series of dif-ferent and separate technical responses. An analysis of the suit-ability and reliability of the Cyber Security measures already inplace in a corporation’s environment canbe done by referring to today’s Best CyberSecurity Practices. Current Best CyberSecurity Practices comprise 8 elements, asfollows:

• Access to the various technologyresources should be controlled throughmechanisms such as user profiles, userIDs, and passwords as well as through net-work segmentation.

• An analysis of the overall vulnerabil-ity of the technology environment shouldbe conducted. This analysis may start withan extensive security assessment conduct-ed by outside consultants; it may also relyon the vulnerability scanning capabilitiesdelivered by some security appliances.Once the vulnerabilities have been identi-fied, they should be addressed with specif-ic short-term solutions as well as with apolicy to implement an automatic testingprocess to uncover new vulnerabilities asthey develop.

• A layered approach to security is preferable as it ensuresthe best protection is available to each technology resource.The multiple layers create additional impediments to hackerintrusions. Perimeter control is attained through protectionimplemented at the gateway level while additional protection,such as anti-virus, can also be implemented on the PC.

• Sophisticated encryption techniques are now readilyavailable, and they should be deployed.

• For maximum effectiveness and reliability, a cyber secu-rity system must be monitored and its performance measuredperiodically to ensure that the stated goals have been reached.

• Mission-critical technology resources must be backed upregularly to ensure that the corporation could recover effective-ly from any system breakdown.

• Periodic assessments of the effectiveness of the cyber



Security measures and of the corpora-tion’s compliance with legislation andindustry-specific security standards,such as Sarbanes-Oxley, PIPEDA, BillC198, and NERC require that extensiveAudit Logs and Reports be available tothe organization’s management.

EXTERNAL AND INTERNAL RISKSThe deployment of an Advanced

Metering Infrastructure project is a com-plex undertaking where numerous com-ponents need to work well together. Asillustrated below, the implementation ofan AMI project results in the distributionoperator being exposed to both externaland internal cyber security risks.

CYBER SECURITYEXTERNAL AND INTERNAL RISKS

External risks result from the vari-ous interconnections with relatedresources while internal risks are theresult of the breakdown of various cor-porate systems and policies.

To counter external risks, differentlayers of protection should be installed,including:

• Perimeter protection through fire-walls and gateways

• Monitoring• Intrusion Detection/Intrusion

Protection• Encryption

Internal risks should be addressedwith:

• Security Policies and Procedures• Access Control• Password Policies• Vulnerability Assessments• Monitoring• Physical Security Measures

Once protection measures havebeen put into place, it is necessary tomonitor results and to take correctiveaction when appropriate.

MANAGEMENT COMMITMENTGiven the complexity involved with

successfully deploying an AMI project,it is essential that a strong managementteam lead the project. This team willensure that the efforts of various depart-ments are well coordinated and that thecyber security program encompasses allaffected operational systems.Furthermore, the team should commit toa periodic cyber security re-assessment

program in order to keep up with con-stantly changing, ever more sophisticat-ed cyber attacks.

INTEGRATIONThe cyber security solutions put into

place to support the AMI deploymentshould be capable of fully integratingwith the operator’s other operational sys-tems and they should support the opera-tor’s cost containment goals.Consequently, operators should favoursolutions that deliver: strong cyber secu-rity, flexibility, open standards, integra-tion with existing operational systems,compliance with relevant standards andregulation, reduced complexity, andcost-effectiveness.

CONCLUSIONPower operators fully recognize the

numerous benefits associated withDemand Side Management.Distribution operators are making con-siderable investments in AdvancedMetering Infrastructure and they expectto enjoy improvements in system effi-ciencies, service reliability, and prof-itability.

It must, however, be clear that thecreation of a 2-way communication net-work between operator and consumercreates a challenging environment whereassets must be protected against today’scomputer hackers and cyber terrorists.The implementation of an effectiveDemand Side Management strategy andof a successful Advanced MeteringInfrastructure project must, therefore,include a comprehensive, well moni-tored, and frequently updated CyberSecurity program.

Peter Vickery’s 25+year successful trackrecord in the Power & Energy industryhas enabled him to develop an in-depthunderstanding of the requirements ofNorth American Transmission &Distribution Operators. While atSiemens, Schlumberger, BC Hydro’sPowerSmart, and JPH International,Peter Vickery designed product and ser-vice solutions that met and surpassed hisclients’ expectations.

Electricity Today26


Are you working safely?Hopefully the answer is yes - but in the majority of cases,

many are working without the proper PPE (Personal ProtectiveEquipment), or choosing not to wear it, or not using safe prac-tices while working on live circuits.

Every year, the Electricity Forum has training courses onsafety and arc flash hazard across Canada, from Vancouver,British Columbia to St. John’s, Newfoundland. This fall, theforum is offering courses on NFPA 70E Arc Flash AwarenessTraining and Advanced Electrical Safety Training during themonths of September and October. These courses are tailormade for those who require basic arc flash and safety trainingor advanced awareness.

The speakers atthe upcoming forumsinclude Jim Anderson ofAlgonquin PowerSystems, who bringsmore than 30 yearsexperience in the electri-cal power industry.

Over the past 30years Jim has developedand delivered trainingprogram for ElectricalSafety, Arc Flash

Awareness and Training, Hazardous Energy Control, GeneralSafety in the Workplace, Job Hazard Analysis, and On the JobTechnical Training and Skills Development as related to PowerProduction.

Len Cicero, President of Lenco Training & TechnicalServices, shares his personal experience with the ongoingdevelopment of CSA Z462, Canada’s version of NFPA 70E.His knowledge of arc flash awareness and the requirements fora company to build and develop an electrical safety programare unparalleled.

Other speakers, like Wes Procyshyn of Manitoba Hydro,Bryan Johnson and Bill Murphy of AGO Industries, enhanceeach training forum with practical experience and decades ofhands-on expertise and industry know-how.

Concurrent with the arc flash and safety training coursesare the Canadian Electrical Code Training seminars.Information on all these courses - and our on-site courses - canbe found at: www.electricityforum.com/forums/courses; or bycalling: 905 686 1040.

July / August 2007

ARE YOU WORKINGSAFELY?

TRAINING FORUMSENSURE YOU WILL

By Don Horne


Electricity Today28

Booth - Exhibitor

1- Voyten Electric2- Filtration Solutions 3- CZAR Inc.

4- Delta Instrument5- Megger6- ZTZ Services International7- Power Substation Services8- Normandy Machine Co.

9- Breaker Service10- Filmax11- Phenix Technologies12- ROHE13- Enervac

CONFERENCES

2007 FINEPOINT CIRCUIT BREAKER TEST &


Booth - Exhibitor

14- Zensol Automation15- NYNAS16- ION Science17- Southern Switch & Contacts18- Vacuum Electric Switch Company19- AVO Training Institute20- National Breaker Services21- Waukesha Electric Systems

/High Voltage Supply22- Velcon Filters23- Solon Manufacturing24- Nichols Applied Technology25- Pascor Atlantic26- E Manufacturing27- DILO28- Vanguard Instruments29- Concorde Specialty Gases and

Equipment Imaging & Solutions30- OMICRON electronics31- Southwest Electric32- INCON33- Polar Technology34- Trantech Radiator Products35- FLIR Systems36- Siemens Power T&D37- Colt Atlantic Services38- Serveron Corporation39- Electrophysics40- PCORE Electric41- Wahl Instruments42- HICO America43- Doble44- Baron USA45- Millworks

46- Joslyn Hi-Voltage47- Powell Electrical Systems48- Shermco Industries49- Neoptix Fiber Optic Sensors 50- Team Industrial Services51- Satin American52- Dow Corning53- PowerPD54- KoCoS55- ISA Test56- LumaSense Technologies57- Solidification Products

International58- AREVA T&D59- Olympus60- Kelman61- ACA Conductor Accessories62- Pennsylvania Breaker63- Eaton64- Fluke65- Midsun Group66- EA Technology67- TJ/H2b68- ABB69- Noram-SMC70- American Polywater71- Square D72- HVB AE Power Systems73- American Electrical Testing Co.74- XEGsys75- Programma Test Products76- Insulboot77- UE Systems78- Mitsubishi Electric Power Products79- Vacudyne80- Reinhausen Manufacturing

MAINTENANCE CONFERENCE

In 1994 Finepoint inaugurated theannual Circuit Breaker Test &Maintenance Conference, the electricpower industry's premier event for sub-station/switchgear maintenance person-nel.

Participants receive practical train-ing from users' perspectives, learn facto-ry authorized test and maintenance pro-cedures, network with their peers, andview cutting-edge products at the sup-plier exhibits each evening in the hospi-tality rooms. Over 490 delegates attend-ed the 2006 conference, representing210 different companies, 46 states, andnine countries.

The conference provides attendees,speakers, and exhibitors with a highquality, low key opportunity toexchange information with their peersand learn from the experts.

Many conference topics focus onlow, medium, and high voltage circuitbreakers. However, related substationand switchgear topics such as powertransformer maintenance, oil testing andfiltration, SF6 gas handling, safe workpractices, and asset management issuesare also covered. Finepoint's objective isto provide useful and unbiased informa-tion that can be immediately applied tosubstation and switchgear maintenance

CONFERENCEAN OCTOBER

TRADITION



work. One unique aspect of the conference is that most speakers

are the electric utility and testing company delegates them-selves, not suppliers.

The four-day conference begins the first Monday of eachOctober with a welcoming reception that evening. The factoryday is on Tuesday. The expo of supplier exhibits debutsTuesday evening and is also open to participants Wednesdayand Thursday evenings. The conference presentations andtraining seminars are scheduled each year on Wednesday,Thursday, and Friday.

FACTORY DAYThe full day at a circuit breaker manufacturing plant has

been a unique feature of the conference since 1996.Participating manufacturers are ABB (Greensburg/Mt.Pleasant PA in 1996, 2000, 2005, and 2007), AREVA(Charleroi PA in 1997, 2001, and 2006), HVB AE PowerSystems (Suwanee GA in 2004), Mitsubishi (Warrendale PA in1998 and 2002), Pennsylvania Breaker and PennsylvaniaTransformer Technology (Canonsburg PA in 2007),andSiemens (Jackson MS in 1999 and 2003).

The 2007 factory day hosts will be ABB, PennsylvaniaBreaker, and Pennsylvania Transformer Technology.Attendance growth has compelled Finepoint to add an addi-tional factory day host for the conference this October andABB has recently accepted the opportunity to also open theirdoors to conference participants. The PA Breaker and PATransformer Technology facilities in Canonsburg can accom-modate only part of the attendees expected to register for thisyear's event, therefore we are expanding to multiple facilitiesfor the first time.

Pennsylvania Breaker LLC (PAB) is the only US ownedmanufacturer of high voltage breakers and has established a90,000 ft2 design, test, and manufacturing facility locatedwithin the 1.2 million sq. ft. Pennsylvania TransformerTechnology Inc. (PTTI) facility in Canonsburg.

Recent renovations include upgrades to the W.E. KerrHigh Voltage Test Center and the addition of state-of-the-artproduction tooling. The PAB facility supports the design, test-ing, and manufacturing of circuit breakers from 72.5kV to550kV, including interrupters and mechanisms.

The PTTI facility is an industry leader in manufacturing atotal range of types and sizes of single- and three-phase powertransformers and voltage regulators. A partner of PTTI, PABwas formed to serve USA users of high voltage breakers withproducts designed to ANSI/IEEE standards for typical USAapplications (60Hz, high fault currents, high X/R, long lines)and with USA based expertise and application support.Finepoint Conference participants will tour both Canonsburgfacilities.

ABB's state-of-the-art high-voltage breaker facility in Mt.Pleasant serves as the headquarters for ABB's High VoltageProduct division in the United States. Mt. Pleasant replaces thenearby Greensburg facility which previously hosted the con-ference in 1996 and 2000. Equipped with the latest in produc-tion and quality systems, the Mt. Pleasant facility is the pinna-cle of high-end breaker manufacturing. A full line of high volt-

Electricity Today30

Do your Contacts tell you whenthey need to be replaced?

Ours Do!

Informer Series® Contacts

Accurately detect the extent of contact wearMore precisely control maintenance activities

Reduce replacement parts inventory

1475 Avenue S. Ste 300, Grand Prairie. TX 75050Toll 866-387-9051 Fax 469-733-1501

October TraditionContinued from page 29


both traditional timing and travel-motion testing and ener-gized first trip testing.

The seminar is being jointly presented by Kelman NorthAmerica, leaders in first trip testing, and VanguardInstruments, leaders in timing and travel-motion testing, onOct. 5. Timing and travel-motion testing of circuit breakershas been around for over 60 years, while first trip testing is arelatively recent enhancement. Both techniques have theirunique benefits and the purpose of the seminar is to thorough-ly cover all aspects of circuit breaker timing and analysis.

Over the last year, global warming has become a front-burner issue. With that comes increased pressure on SF6 usersto eliminate even the smallest gas emissions. Borrowing onthe 15+ years of experience in the U.S. utility market (50+years in Europe), DILO Company's Eric Campbell and LukasRothlisberger will conduct the SF6 gas handling and manage-ment seminar with the U.S. Environmental ProtectionAgency's Climate Change Division SF6 Program ManagerJerome Blackman.

Based on feedback and input from customers, DILO willpresent current industry practices with regard to SF6 handling,safety, and transportation issues. Topics will include how toefficiently work with SF6, including complete cylinder emp-tying, and consolidation. Proper breaker entry procedure, safe-ty equipment, cleaning process, evacuation of air, and refillingof SF6 will also be discussed.

A case study of a recent breaker replacement project -describing the testing of the SF6, its removal, cleaning, andeventual refill into newer equipment - will be included.

age dead tank circuit breakers (DTB) ranging from 38 to 800kV, non-synchronous and synchronous, with interruptingcapacities in excess of 80 kA are manufactured in this ISO-9001, ISO-14001 and OHSAS 18001 compliant facility.

The complete line of ABB circuit breaker and GIS legacybrands (ABB, Asea, BBC, ITE, and Westinghouse) continue tobe actively supported through the High Voltage Service group,also headquartered at the Mt. Pleasant facility. The servicegroup boasts the industry's largest available parts inventorylocated within their Greensburg PA service shop. ABB's ser-vice capabilities include authentic OEM parts, life extensionkits, up-rates, retrofits, re-manufacturing, field services,turnkey installations, fleet assessments, customized products,diagnostics, monitoring, and customizable training.

Finepoint Conference participants will tour both the newDTB factory and the service shop while participating in inter-active technology presentations.

HALF-DAY TRAINING SEMINARSIn addition to more than a dozen presentations, each year

the conference features two half-day training seminars at noadditional charge. The 2007 conference includes seminars ofvital interest to the electric utility industry. The "SF6 GasHandling and Management" seminar jointly presented by theEPA and DILO is on Wednesday afternoon, October 3, and the"Circuit Breaker Timing and Analysis" seminar jointly pre-sented by Kelman and Vanguard Instruments is on Fridaymorning, October 5.

The timing and analysis seminar includes details about



There are different constraints that limit the power trans-mission capacity of a system. The power transmission capaci-ty in permanent regime is defined by:

A. Switchgear characteristicsCertain lines have load capacity limited by some of the

switchgear elements associated to them. The element with thesmaller rated current in any end of the line is identified.

B. Environmental specificationsThe determination of load capacity in high voltage cables

must take into account on the one hand the thermal conditionsof the conductors work, such as temperature, wind speed, andwind direction, and on the other hand the electric conditions ofoperation. This is to respect minimum safety distances and

maintain the voltage and the network stability within suitablelimits.

C. Voltage dropsIn the network, lines transmit a great amount of energy

from the generating ends to the consuming ones. In thesecases, if the receiving zones do not have compensating reac-tive elements, the voltage can drop below the limit fixed byquality criteria.

In such situations, it is advisable to limit the transmissionof these lines to prevent excessively low voltages in the receiv-ing end as well as to prevent a possible voltage collapse of thetransformer regulators because of a performance over theirpossibilities.

D. System stabilityCases of long interconnection lines between zones with no

reactive problems are considered with the voltages maintainedin an acceptable limit; but there can be situations in whichstrong interchanges of power demand an excessive angularphase angle between the positions of the generator rotors ofeach area. It is advisable to limit the transmission of these lineswith a view to avoiding the loss of stability and electric sepa-ration between both zones.

Studies of rated capacities of the different elements thattake part in transmission and distribution have been made, inan effort to establish the necessity of substitution of those withinsufficient capacity and to be able to establish a plan of equip-ment maintenance and repair..

These constraints in the operation of the lines are detect-ed, based on the following criteria: maximum possible currentto transmit over the lines, maximum current of transmission bythermal limit of the lines and maximum permissible current,due to switchgear connected to the lines.

TRANSMISSION CAPACITY UPGRADING BY INCREASINGVOLTAGE

Voltage is a measure of the electromotive force necessaryto maintain a flow of electricity on a transmission line. Voltagefluctuations can occur due to variations in electricity demandand to failures on transmission or distribution lines.Constraints on maximum voltage levels are set by the designof the transmission line. If the maximum is exceeded, short cir-cuits, radio interference, and noise may occur, transformersand other equipment at the substations and/or customer facili-ties may be damaged or destroyed. Minimum voltage con-straints also exist based on the power requirements of cus-tomers. Low voltages cause inadequate operation of a cus-tomer’s equipment and may damage motors.

Electricity Today32


POWER TRANSMISSION CAPACITY UPGRADEOF OVERHEAD LINES - PART I

By D.M. Larruskain, I. Zamora, O. Abarrategui, A. Iraolagoitia, M. D. Gutiérrez, E. Loroño and F. dela Bodega, Department of Electrical Engineering, E.U.I.T.I., University of the Basque Country


Voltage on a transmission line tendsto “drop” from the sending end to thereceiving end. The voltage drop along theAC line is almost directly proportional toreactive power flows and line reactance.The line reactance increases with thelength of the line. Capacitors and induc-tive reactors are installed, as needed, onlines to partially control the amount ofvoltage drop. This is important becausevoltage levels and current levels deter-mine the power that can be delivered tocustomers.

In recent years there hasbeen much emphasis placedonmaking appropriate modifi-cations to existing overheadlines and to eliminating old ACtransmission lines and substi-tuting them with new compactAC lines.

Both these solutions leadto an increase in the transmit-ted power by the overhead lineincreasing the rated voltage.This is possible by utilizing theexperience acquired fromusing HVAC lines and permit-ting reduced safety margins indesigning clearances. For com-pact AC lines, insulatedcrossarms and a shorter spanare also used, thereby reducingthe line sag so that a substantialincrease in power density isachieved.

TRANSMISSION CAPACITYUPGRADING BY INCREASING

CURRENT DENSITYWhen the flow of elec-

trons passes through the line, itproduces heat and the conduc-tor’s temperature increases. Itis necessary to make a thermalstudy to determine if the con-ductor can stand that tempera-ture. The temperature of theconductor is limited by twofactors:1) The limit of the conductor’s

material2) Conductor – ground distance

Although aluminium conductorshave been used in overhead transmissionsince the end of the 19th century, theirwidespread use did not occur until the1940s, when copper was designated as avital war material and was no longeravailable for use by electric utilities. To

obtain the desired strength required fortransmission lines, lightweight alumini-um was combined with the high tensilestrength of steel in the development ofaluminium conductor steel reinforced(ACSR). Today, most overhead transmis-sion lines use this conductor construc-tion.

Steel can stand high temperatures,up to 200ºC with no changes in the con-ductor’s properties. Aluminium, on theother hand, experiences change in themechanical properties when the tempera-

ture is higher than 90ºC. The temperatureis a function of the electrical current andenvironmental conditions. On a continu-ous basis, ACSR may be operated at tem-peratures up to 100ºC and, for short termemergencies, at temperatures as high as125°C without any significant change inthe physical properties.

Given the many changes in the way

power transmission systems are beingplanned and operated, there is a need toreach higher current densities in existingtransmission lines, to increase the ther-mal rating of existing lines. There are dif-ferent ways to achieve this increase:

1) Increase the maximum allowableoperating temperature to 100°C. Forexample, if the line is limited to a modesttemperature of 50°C to 75°C, and theelectrical clearance is sufficient to allowan increase in sag for operation at a high-er temperature, then the thermal rating of

the line can be increased. If suffi-cient clearance does not exist in allspans, then conductor attachmentpoints may be raised, conductor ten-sion increased or other mechanicalmethods applied to obtain the neces-sary clearance at the higher temper-ature.

2) Use dynamic ratings or less-conservative weather conditionsrelating to wind speed and ambienttemperatures. For example, if theexisting line is already rated at atemperature near 100°C, and a mod-est increase of 5% to 15% is desired,then monitors can be installed andthe higher ratings used when windspeed is higher than the standard 0.6m/s and the ambient temperature islower than 40°C.

3) Replace the conductor with alarger one or with one capable ofcontinuous operation above 100°C.These solutions would be ideal if theline was already limited to 100°C,and the thermal rating increased bymore than 25%. Given the low cost,high conductivity and low density ofaluminium, no other high-conduc-tivity material is presently used.Therefore, replacement with a largerconductor will result in an increasedload on existing structures becauseof an increase of wind/ice and ten-sion.

The thermal rating of an exist-ing line can be increased about 50%by using a replacement conductorthat has twice the aluminium area of

the original conductor. The larger con-ductor doubles the original strain struc-ture tension loads and increases trans-verse wind/ice conductor loads on sus-pension structures by about 40%. Suchlarge load increases typically wouldrequire structure reinforcement orreplacement. This drawback to the use ofa larger conductor may be avoided by


Fig. 1. Current capacity in function of the cross sectionalarea

Fig. 2. Sag in function of the conductor temperature for aspan length of 400m


Electricity Today34

using the high-temperature, low-sag(HTLS) conductor, which can be operat-ed at temperatures above 100°C whileexhibiting stable tensile strength andcreep elongation properties.

Practical temperature limits of up to200°C have been specified for some con-ductors. Using the HTLS conductor,which has the same diameter as the orig-inal, at 180°C increases the line rating by50% but without any significant changein structure loads. If the replacementconductor has a lower thermal elongationrate than the original, then the structureswill not have to be raised.

Although the use of a larger conduc-tor provides a reduction in losses over thelife of the line while operatingtemperatures remain at a modestlevel, the use of the HTLS con-ductor reduces capital invest-ment by avoiding structuremodifications. In either case,replacing existing conductorsshould improve the reliability ofthe line because the conductor,connectors and hardware will allbe new.

INCREASING TRANSMIS-SION CAPACITY OF OVERHEAD

LINES USING HTLS CONDUC-TORS

Replacing original ACSRconductors with HTLS conduc-tors with approximately thesame diameter is one method ofincreasing transmission linethermal rating. HTLS conduc-tors are effective because they are capa-ble of:1) High-temperature, continuous opera-

tion above 100°C without loss oftensile strength or permanent sag-increase so that line current can beincreased.

2) Low sag at high temperature so thatground and underbuild clearancescan still be met without raising orrebuilding structures.

The original conductor’s “initialinstalled sag” increases to a final “every-day sag”, typically at 16°C with no ice orwind, as a result of both occasionalwind/ice loading and the normal alumini-um strand creep elongation that is a resultof tension over time. This final sag mayincrease occasionally because ofice/wind loading or high electrical loads,but these effects are reversible.

For most transmission lines, maxi-

mum final sag is the result of electricalrather than mechanical loads. It is impor-tant that any replacement conductor beinstalled so its final sag under maximumelectrical or mechanical load does notexceed the original conductor’s final sagand the existing structures need not beraised or new structures added. Underthese circumstances, where structurereinforcement or replacement is to beavoided, HTLS conductors are used toadvantage.

New construction, long-span cross-ings can be achieved with shorter towers.These can be accomplished using theexisting right-of-ways and using all theexisting tower infrastructure, thereby

avoiding extensive rebuilding, avoidingdifficult and lengthy permitting, andreduced outage times.

TYPES OF HTLS CONDUCTORSConductors are constructed from

helically stranded combinations of indi-vidual wires where galvanized steelwires are used for mechanical reinforce-ment, aluminium wires for the conduc-tion of electricity, and hard-drawn alu-minium for both mechanical and electri-cal purposes.

Desirable properties for reinforcingcore-wire material include a high elasticmodulus, a high ratio of tensile strengthto weight, the retention of tensilestrength at high temperatures, a low plas-tic and thermal elongation, a low corro-sion rate in the presence of aluminiumand a relatively high electrical conductiv-ity. The material must be easy to fabri-cate into wire for stranding.

Among the choices available forHTLS conductors are:1) ACSS and ACSS/TW (Aluminium

Conductor Steel Supported)Annealed aluminium strands over aconventional steel stranded core.Operation to 200°C.

2) ZTACIR (Zirconium alloy AluminiumConductor Invar steel Reinforced)High-temperature aluminiumstrands over a low-thermal elonga-tion steel core. Operation to 150ºC(TAI) and 210°C (ZTAl).

3) GTACSR (Gap Type heat resistantAluminium alloy Conductor SteelReinforced) High-temperature alu-minium, grease-filled gap between

core/inner layer.Operation to 150°C.GZTACSR (Gap Typesuper heat resistantAluminium alloyConductor SteelReinforced).4) ACCR (AluminiumConductor CompositeReinforced) High-tem-perature alloy alumini-um over a compositecore made from alumi-na fibres embedded in amatrix of pure alumini-um. Operation to210°C.5) CRAC (CompositeReinforced AluminiumConductor) Annealedaluminium over fibre-glass/ thermoplast ic

composite segmented core. Probableoperation to 150°C.

6) ACCFR (Aluminium ConductorComposite Carbon FibreReinforced) Annealed or high-tem-perature aluminium alloy over a coreof strands with carbon fibre materialin a matrix of aluminium. Probableoperation to 210°C.

TRANSMISSION CAPACITY UPGRAD-ING BY USING AC LINES TO TRANSMIT

DC POWERThe fast development of power elec-

tronics based on new and powerful semi-conductor devices has led to innovativetechnologies, such as HVDC, which canbe applied to transmission and distribu-tion systems. The technical and econom-ical benefits of this technology representan alternative to the application in ACsystems.

Some aspects, such as deregulation

Fig. 3. HVAC-HVDC cost


in the power industry, opening of the marketfor delivery of cheaper energy to customersand increasing the capacity of transmission anddistribution of the existing lines are creatingadditional requirements for the operation ofpower systems. HVDC offer major advantagesin meeting these requirements.

HVDC transmission systems are point-to-point configurations where a large amount ofenergy is transmitted between two regions. Thetraditional HVDC system is built with linecommutated current source converters, basedon thyristor valves. The operation of this con-verter requires a voltage source like synchro-nous generators or synchronous condensers inthe AC network at both ends. The current com-mutated converters cannot supply power to anAC system which has no local generation. Thecontrol of this system requires fast communi-cation channels between the two stations.

FEASIBILITY OF HVDC TRANSMISSIONA HVDC system can be ‘monopolar’ or

‘bipolar’. The monopolar system uses onehigh-voltage conductor and ground return.This is advantageous from an economic pointof view, but is prohibited in some countriesbecause the ground current causes corrosion ofpipe lines and other buried metal objects.However, in Europe, monopolar systems are inoperation. Most of them are used for subma-rine crossings.

The bipolar system uses two conductors,one with plus and one with minus polarity. Themid point is grounded. In normal operation, thecurrent circulates through the two high-voltageconductors without ground current. However,in case of conductor failure, the system cantransmit half of the power in monopolar mode.Besides, this operation can be maintained for alimited time only.

Recently, ABB and Siemens started tobuild HVDC systems using semiconductorswitches (IGBT or MOSFET) and pulse widthmodulation (PWM). The capacity of a HVDCsystem with VSCs is around 30-300 MW.Operating experience is limited but many newsystems are being built worldwide. The PWMcontrolled inverters and rectifiers, with IGBTor MOSFET switches, operate close to unitypower factor and do not generate significantcurrent harmonics in the AC supply. Also, thePWM drive can be controlled very accurately.Typical losses claimed by ABB for two con-verters is 5%.

DC VERSUS ACThe vast majority of electric power trans-

missions use three-phase alternating current.The reasons behind a choice of HVDC insteadof AC to transmit power in a specific case areoften numerous and complex. Each individualtransmission project will display its own set ofreasons justifying the choice.

July / August 2007


General characteristicsThe most common arguments

favouring HVDC are:1) Investment cost. A HVDC trans-

mission line costs less than an AC linefor the same transmission capacity.However, the terminal stations are moreexpensive in the HVDC case due to thefact that they must perform the conver-sion from AC to DC and vice versa. Onthe other hand, the costs of transmissionmedium (overhead lines and cables),land acquisition/right-of-way costs arelower in the HVDC case. Moreover, theoperation and maintenance costs arelower in the HVDC case. Initial loss lev-els are higher in the HVDC system, butthey do not vary with distance. In con-trast, loss levels increase with distance ina high voltage AC system

Above a certain distance, the socalled “break-even distance”, the HVDCalternative will always give the lowestcost. The break-even-distance is muchsmaller for submarine cables (typicallyabout 50 km) than for an overhead linetransmission. The distance depends onseveral factors, as transmission medium,different local aspects (permits, cost oflocal labour etc.) and an analysis must bemade for each individual case (Fig. 3).

2) Long distance water crossing. In along AC cable transmission, the reactivepower flow due to the large cable capac-itance will limit the maximum transmis-sion distance. With HVDC there is nosuch limitation, so, for long cable links,HVDC is the only viable technical alter-native.

3) Lower losses. An optimizedHVDC transmission line has lower loss-es than AC lines for the same powercapacity. The losses in the converter sta-tions have, of course, to be added, butsince they are only about 0.6% of thetransmitted power in each station, thetotal HVDC transmission losses comeout lower than the AC losses in practical-ly all cases. HVDC cables also havelower losses than AC cables.

4) Asynchronous connection. It issometimes difficult or impossible to con-nect two AC networks due to stabilityreasons. In such cases, HVDC is the onlyway to make an exchange of powerbetween the two networks possible.There are also HVDC links between net-works with different nominal frequencies(50 and 60 Hz) in Japan and SouthAmerica.

5) Controllability. One of the funda-mental advantages with HVDC is that it

is very easy to control the active power inthe link.

6) Limit short circuit currents. AHVDC transmission does not contributeto the short circuit current of the inter-connected AC system.

7) Environment. Improved energytransmission possibilities contribute to amore efficient utilization of existingpower plants. The land coverage and theassociated right-of-way cost for a HVDCoverhead transmission line is not as highas for an AC line. This reduces the visu-al impact. It is also possible to increasethe power transmission capacity forexisting rights of way. There are, howev-er, some environmental issues that mustbe considered for converter stations, suchas: audible noise, visual impact, electro-magnetic compatibility and use ofground or sea return path in monopolaroperation.

In general, it can be said that aHVDC system is highly compatible withany environment and can be integratedinto it without the need to compromiseon any environmentally important issuesof today.

See September’s issue of ElectricityToday for Part II.

Electricity Today36



Electricity Today38

This article discusses the use ofadvanced technologies to enhance per-formance of the national transmissiongrid (NTG). We address present anddeveloping technologies that have greatpotential for improving specific aspectsof NTG performance, strategic impedi-ments to the practical use of these tech-nologies, and ways to overcome theseimpediments in the near term.

Research and development (R&D)infrastructure serving power transmis-sion is as badly stressed as the grid itself,for many of the same reasons. The needsare immediate, and the immediate alter-natives are few.

Timely and strategically effectivetechnology reinforcements to the NTGneed direct, proactive federal involve-ment to catalyze planning and execution.Longer-term adjustments to the R&Dinfrastructure may also be needed, in partenergy policy can evolve as the NTGevolves.

POWER SYSTEM COMPONENTSAND RECIPROCAL IMPACTS

The power system has three compo-nents: generation, load, and transmission.Electric power is produced by genera-tors, consumed by loads, and transmittedfrom generators to loads by the transmis-sion system.

Typically, the “transmission system”(or “the grid”) refers to the high-voltage,networked system of transmission linesand transformers. The lower-voltage,radial lines and transformers that actual-ly serve load are referred to as the “dis-tribution system.” The voltage differencebetween the transmission system and thedistribution system varies from utility toutility; 100 kV is a typical value. Thispaper focuses only on advanced tech-nologies for the transmission system.

It is important to understand recipro-cal impacts among the transmission sys-tem, load, and generation.

Because the transmission system’sjob is to move electric power from gen-

eration to load, any technologies thatchange or redistribute generation and/orload will have a direct impact on thetransmission system. This can be illus-trated using a simple two-bus, two-gen-erator example shown in one-line form inFigure 1. The solid lines represent thebuses, the circles represent the genera-tors, and the large arrow represents theaggregate load at bus 2. Three transmis-sion lines join the generator at bus 1 tothe load and generation at bus 2.

Superimposed on the transmissionlines are arrows whose sizes are propor-tional to the flow of power on the lines.The pie charts for each line indicate therelation between the loading on each lineand its rated capacity.

The upper and middle transmissionlines have a rating of 150 MVA, and thelower line has a rating of 200 MVA. Inaddition, we assume that the bus 1 gener-ation is more economical than the gener-ation at bus 2, and the entire load is beingsupplied remotely from the bus 1 genera-tor. With a bus 2 load of 420 MW, thepower distributes among the three linesbased on their impedances (which are not

identical), so the upper line is loaded at67 percent, the middle at 89 percent, andthe lower at 100 percent. Note: there are13 MW of transmission line losses in thiscase.

TRANSFER CAPACITYA natural question to ask is: what is

the transfer capacity of the transmissionsystem described in Figure 1? That is,how much power can be transferred frombus 1 to bus 2?

The answer is far from straightfor-ward. At first glance, the transfer capaci-ty appears to be 420 MW because thisamount of power causes the first line toreach its limit. However, this answer isbased on the assumption that all lines arein service. As defined by the NorthAmerican Electric Reliability Council(NERC), transfer capacity includes con-sideration of reliability. A typical reliabil-ity criterion is that a system be able towithstand the unexpected outage of anysingle system element; this is known asthe first contingency total transfer capa-

TRANSMISSION TECHNOLOGIES

EXAMINING ADVANCED TRANSMISSIONTECHNOLOGIES - PART I

By Jeff Dagle, Steve Widergren, John Hauer, Pacific Northwest National LaboratoryTom Overbye, University of Illinois at Urbana-Champaign


Figure 1: Two-Bus Example with No Local Generation


The Automatic Meter Reading Association (AMRA)endorses the far-sighted leadership embodied in a NationalAssociation of Regulatory Utility Commissioners (NARUC)resolution to eliminate regulatory barriers to the broad imple-mentation of advanced metering infrastructure (AMI).

The resolution acknowledged the role of AMI in support-ing the implementation of dynamic pricing and the resulting

benefits to con-sumers. The reso-lution further iden-tified the value ofAMI in achievingsignificant utilityoperational costsavings in the areasof outage manage-ment, revenue pro-tection and assetmanagement.The resolution

also called for AMIbusiness caseanalyses to identi-fy cost-effectivedeployment strate-gies, endorsedtimely cost recov-ery for prudentlyincurred AMIexpenditures andmade additional

recommendations on rate making and tax treatment of suchinvestments.

“We commend NARUC on its visionary policy statement,and AMRA recommends that state jurisdictions give close con-sideration of the NARUC resolution in their deliberationsunder the Energy Policy Act of 2005,” said Bernie Bujnowski,AMRA Sr. Vice President of Advocacy.

AMRA, the international voice of the AMR/AMI industry,provides information critical to the understanding and applica-tion of the wide range of AMR/AMI technologies. Throughindustry analyses, symposia and relevant publications, AMRAserves the business interests of utilities and utility technologysuppliers.

July / August 2007

AMRA APPLAUDSNARUC RESOLUTION

ELIMINATINGREGULATORY

BARRIERS TO AMI

“We commend NARUCon its visionary policystatement, and AMRArecommends that statejurisdictions give closeconsideration of theNARUC resolution intheir deliberationsunder the EnergyPolicy Act of 2005,”said Bernie Bujnowski,AMRA Sr. VicePresident of Advocacy.


Electricity Today40

bility (FCTTC). Based on this criterion,Figure 2 shows the limiting case with anassumed contingency on the lower line,which results in a transfer capability ofonly 252 MW. Which number is correct?

The answer depends on system oper-ational philosophy and on the availabili-ty of high-speed system controls.

If the operational philosophyrequires that no load be involuntarily lostfollowing any individual contingency,and if there are no mechanisms to quick-ly increase the generation at bus 2, vol-untarily decrease the load at bus 2, orredistribute the flow between the remain-ing upper two lines, then the limit wouldbe 252 MW. With these limitations, theonly way to increase the transfer capaci-ty would be to construct new lines.

However, if we relax one or more ofthese conditions, the transfer capacitycould be increased without constructionof new lines. For example, one approachwould be to provide at least some of thebus 2 load with incentives so that, fol-lowing the contingency, some customerson bus 2 would voluntarily curtail theirloads.

Incentives might involve price-feed-back mechanisms or agreements to allowthe system operator to curtail loadthrough some type of direct-control loadmanagement or interruptible demand.Another approach would be to have amechanism for quickly committing somelocal bus 2 generation. Availability oflocal generation reduces the net loadingon the transmission system and canincrease its capacity. A third approachwould be to use advanced power elec-tronics controls such as flexible ACtransmission system (FACTS) devices to

balance the load between the upper twolines.

The unifying themes of these alter-native approaches are knowledge aboutthe real-time operation of the system,availability of effective controls, and aninformation infrastructure that permitseffective use of the controls.

To understand these themes, it isimportant to understand the complexityof the actual national transmission grid.

COMPLEXITY OF THE NATIONALTRANSMISSION GRID

The term “national transmissiongrid” is something of a misnomer. TheNorth American transmission grid actual-ly consists of four large grids, each pri-marily a synchronous alternating current(AC) system. Together, these four gridsspan parts of three sovereign countries(U.S., Canada, and Mexico). By far thelargest grid is the EasternInterconnection, which supplies power tomost of the U.S. east of the RockyMountains as well as to all the Canadianprovinces except British Columbia,Alberta, and Quebec. The WesternInterconnection supplies most of the U.S.west of the Rockies, as well as BritishColumbia, Alberta, and a portion of Baja,California. The remaining two grids arethe Electric Reliability Council of Texas(ERCOT), which covers most of Texas,and the province of Quebec. In contrastto the two-bus example presented above,the Eastern and the WesternInterconnections contain tens of thou-sands of high-voltage buses and manythousands of individual generators and

loads. Because the individual grids areasynchronous with one another, nopower can be transferred among themexcept in small amounts through a fewback-to-back direct current (DC) links.Several major DC transmission lines arealso used within the individual grids forlong-distance power transfer.

At any given time the loading on thegrid depends on where power is beinggenerated and consumed. Load is con-trolled by millions of individual cus-tomers, so it varies continuously.Because electricity cannot be readilystored, generation must also vary contin-uously to track load changes. In addition,the impedances of the many thousands ofindividual transmission lines and trans-formers dictate grid loading. With sever-al notable exceptions, there is no way todirectly control this flow—electrons flowas dictated by the laws of physics.Because electricity propagates throughthe network very rapidly, power can betransferred almost instantaneously (with-in seconds) from one end of the grid tothe other. In general, this interconnectiv-ity makes grid operations robust and reli-able. However, it also has a detrimentaleffect if the grid fails; failures in onelocation can quickly affect the entire sys-tem in complex and dramatic ways, andlarge-scale blackouts may result.

The grid’s ability to transfer poweris restricted by thermal flow limits onindividual transmission lines and trans-formers; minimum and maximum limitson acceptable bus-voltage magnitudes;

Transmission TechnologiesContinued from page 38

Figure 2: Two-Bus Example with Limiting Contingency




and region-wide transient, oscillatory,and voltage-stability limitations. GivenNERC’s reliability requirements, theselimits must be considered not only forcurrent and actual system operating pointbut also for a large number of statistical-ly likely contingent conditions as well.The complexity of maximizing the powertransfer capability of the grid whileavoiding stressing it to the point of col-lapse cannot be overstated.

TECHNOLOGIES TO INCREASETRANSFER CAPACITY

The goal of this issue paper is toexamine technologies that can be used toincrease the grid’s power-transfer capa-bility. This increase can be achieved by acombination of direct technical rein-forcements to the grid itself along withindirect information and control rein-forcements that improve grid manage-ment practices and infrastructure.

Direct reinforcement of the grid

includes new construction and broad useof improved hardware technology.

Strategic decisions regarding thesetwo types of improvements are a functionof grid management—planning, develop-ment, and operation. Grid managementinvolves recognizing transmission needs,assessing options for meeting thoseneeds, and balancing new transmissionassets and new operating methods.Timely development and deployment ofrequisite technology are essential to rein-forcing the grid.

Requisite technology may not meannew technology. There is a massive back-log of prototype technology that can,given means and incentives, be adaptedto power system applications.

Indirect grid reinforcement includesimproving grid management by means oftechnology. Historically, the transmissionsystem was operated with very little real-time information about its state. Duringthe past few decades, advances in com-puter and communication technology ingeneral and SCADA (supervisory controland data acquisition) and EMS (energymanagement system) technology in par-

ticular have greatly improved data capa-bilities. Significant real-time data arenow available in almost every controlcenter, and many centers can conductadvanced on-line grid analysis. Despitethese improvements, more can andshould be done.

In the control center, additional dataneeds to be collected, better algorithmsneed to be developed for determiningsystem operational limits, and bettervisualization methods are needed to pre-sent this information to operators.Beyond the control center, additionalsystem information needs to be presentedto all market participants so that they canmake better-informed decisions aboutgeneration, load, and transmission sys-tem investments.

INSTITUTIONAL ISSUES THAT AFFECTTECHNOLOGY DEPLOYMENT

In order to effectively discuss therole of advanced transmission technolo-gies, we have to consider how theirdeployment is either hindered or encour-aged by institutional issues. Ultimately,the bottom line is economics— technolo-

Electricity Today42

Transmission TechnologiesContinued from page 40


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gies that are viewed as cost effective willbe used, and those that are considered toocostly will not. The issue of cost is notsimple; public policy must address howcosts and benefits should be allocated.

For example, it is difficult to beat theeconomics of traditional overhead trans-mission lines for bulk power transfer.The lines are cheap to build and entailrelatively few ongoing expenses. But thesiting of new transmission lines is not sosimple; right of way may be difficult toobtain, and new lines may face signifi-cant public opposition for a variety ofreasons from aesthetic to environmental.Advanced technologies can reinforce thegrid, minimizing the need for new over-head lines, but usually at higher cost thanwould be paid to build overhead lines.The challenge is to provide incentivesthat will encourage the desired transmis-sion investments.

Unfortunately, in recent years theuncertainties associated with electricityindustry restructuring have hamperedprogress in transmission reinforcement.The boundaries between responsibilitiesfor operation and planning were once

clearly delineated, but these responsibili-ties are now shifting to restructured orentirely new transmission organizations.This process is far from complete and hasgreatly weakened the essential dialoguebetween technology developers andusers. Development of new technologymust be closely linked to its actualdeployment for operational use.Together, these activities should reflect,serve, and keep pace with the evolvinginfrastructure needs of transmission orga-nizations. The current uncertainty dis-courages this cohesiveness.

The details and the needs of theevolving infrastructure for grid manage-ment are unclear, and all parties areunderstandably averse to investmentsthat may not be promptly and directlybeneficial. Some utilities are concernedthat transmission investments may be ofgreater benefit to their competitors thanto themselves. In the near term, relief ofcongestion may actually harm their busi-nesses.

As a result of such forces, manypromising technologies are stranded atvarious points in route from concept to

practical use. Included are large-scaledevices for routing power flow on thegrid, advanced information systems toobserve and assess grid behavior, real-time operating tools for enhanced man-agement of grid assets, and new systemplanning methods that are robust in rela-tion to the many uncertainties that arepresent or are emerging in the new powersystem.

Another important issue is that sometechnologies that would enable healthyand reliable energy commerce are notperceived as profitable enough to attractthe interest of commercial developers.Special means are needed to develop anddeploy these technologies for the publicgood. Involvement by the federal utilitiesand national laboratories may be neces-sary for timely progress in this area, aswell as a broadening of some activities ofEPRI or similar umbrella organizationsfocused on energy R&D along withdevelopment of better mechanisms tospur entrepreneurial innovation.

Look for Part II in the September issue ofElectricity Today

43July / August2007




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Electricity Today46


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